Directory

• Tobacco is a legacy recreational drug that causes cancers, and kills over 6m people each year
• No new food, drink, recreational or over the counter drug with a similar adverse health profile would ever be approved in the modern world
• Smoking causes 150 extra mutations in every lung cell
• New research demonstrates that smoking causes cancers in organs not exposed to smoke such as the bladder, kidney and pancreas
• Smoking triggers cell mutations that can cause cancer years after quitting
• Anti-smoking campaigns have decreased the prevalence of smoking, but incidence rates have increased because of population growth
• Identifying all the cancer genes will eventually improve treatments

Tobacco is the only legal drug that kills millions when used exactly as intended by manufacturers. New research into the root causes of cancer demonstrates how tobacco smoke mutates DNA, and gives rise to more than 17 types of cancers, and surprisingly, causes cancers in organs not directly exposed to tobacco smoke.
 

---

Cell mutation and the body’s natural resistance

 
A mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. The more mutations a cell acquires, the more likely it is to turn cancerous.

---

 

Decreased prevalence, but increased incidence of smoking

Globally, smoking prevalence - the percentage of the population that smokes regularly - has decreased, but the number of cigarette smokers worldwide has increased due to population growth. Today, over 1bn people worldwide smoke tobacco, which each year causes nearly 6m early deaths, many different cancers, pain, misery and grief; not to mention the huge costs to healthcare systems and the loss of productivity.  If current trends continue tobacco use will cause more than 8m deaths annually by 2030. On average, smokers die 10 years earlier than nonsmokers.
 

---

Cancer and the body’s natural resistance

Cancer is a condition where cells in a specific part of the body mutate and reproduce uncontrollably. There are over 200 different types of cancer. Cancerous cells can invade and destroy surrounding healthy tissue and organs. Cancer sometimes begins in one part of the body before spreading to other areas. This process is known a metastasis. The body has a capacity to naturally resist cancer, through tumor suppressor genes, which function to restrain inappropriate mutations, and stimulate cell death to keep our cells in proper balance.New therapies that boost the body’s own immune system to fight cancer are believed to be a game-changer in cancer treatment.

---

Cancer and the causes of cancer

Whitfield Growdon, a surgical oncologists from Harvard University Medical School and the Massachusetts General Hospital in Boston, describes cancer and the causes of cancer:
 

What is cancer?



What causes cancer?

 

---

Epidemiology of smoking

Today, it is widely accepted that tobacco use is the single most important preventable health risk in the developed world, and an important cause of premature death worldwide. The research of the British epidemiologists Richard Doll and Tony Bradford Hill, more than anyone else, is responsible for the link between tobacco use and lung cancer. Following reports of several case-controlled studies in the early 1950’s Doll and Hill published findings of a larger case-controlled study in 1954 in the British Medical Journal, which suggested that smoking was, "a cause, and an important cause" of lung cancer. This was followed by the publication of further research findings in 1956. Doll and Hill’s latter study confirmed their earlier case-controlled findings: that there is a higher mortality rate among smokers than in non-smokers, and a clear dose-response relationship between the quantity of tobacco used, and the death rate from lung cancer. Data also indicated a significant progressive reduction in mortality rates with the length of time following the cessation of smoking.

---

 

US Surgeon General Report of smoking and lung cancer

The research of Doll and Hill, along with other cohort studies published in the 1950s, formed the basis for the game-changing 1964 report of the US Surgeon General, which concluded that, "Cigarette smoking is causally related to lung cancer in men; the magnitude of the effect of cigarette smoking far outweighs all other factors". This led to groundbreaking research on tobacco use, and investments by governments and nonprofit organizations to reduce tobacco prevalence and cigarette consumption, which in some developed countries has been successful. In 2003, the Framework Convention on Tobacco Control was adopted by the World Health Organization, and has since been ratified by 180 countries.  
 

The best and the worst countries for smoking related lung cancer
 

Between 1980 and 2012 age-standardized smoking prevalence decreased by 42% for women and 25% for men worldwide. Canada, Iceland, Mexico, and Norway have reduced smoking by more than half in both men and women since 1980. The greatest health risks for both men and women are likely to occur in countries where smoking is pervasive and where smokers consume a large quantity of cigarettes. These countries include China, Ireland, Italy, Japan, Kuwait, South Korea, the Philippines, Uruguay, Switzerland, and several countries in Eastern Europe. The number of cigarettes smoked worldwide has grown to more than 6 trillion. In 75 countries: smokers consume an average of more than 20 cigarettes a day.
 

Smoking-related deaths in the UK and US

19% (10m) of adults in the UK, and 17% (40m), of adults in the US are current cigarette smokers, a figure, which has more than halved since the mid 1970s. Results from a 50-year study shows that half to two thirds of all lifelong cigarette smokers will be eventually killed by their habit. Death is usually due to lung cancer, chronic obstructive lung disease and coronary heart disease. Many who suffer from these diseases experience years of ill health and subsequent loss of productivity. Every year, around 96,000 people in the UK, and 480,000 people in the US, die from diseases caused by smoking. This equates to 226 and 1,300 smoking-related deaths every day in the UK and US respectively.
 

Costs

In addition to death and sickness, tobacco use also imposes a significant economic burden on society. These include direct medical costs of treating tobacco-induced illnesses, indirect costs including loss of productivity, fire damage and environmental harm from cigarette litter and destructive farming practices. Cigarettes sales contribute significant tax revenues to national coffers; the industry employs tens of thousands of people who also pay taxes. Notwithstanding, the total burden caused by tobacco products outweighs any economic benefit from their manufacture and sale.
 

Direct link between the number of cigarettes smoked and cancers

Scientists from the Wellcome Trust Sanger Institute near Cambridge, UK, the Los Alamos National Laboratory in New Mexico, and others have discovered a direct link between the number of cigarettes smoked and the number of mutations in the tumor DNA, and that smoking also causes cancers in organs not exposed to tobacco smoke.

Research published in the Journal Science in 2016 analyzed more than 5,000 cancer tumors from smokers and nonsmokers, and concluded that if you smoke even a few cigarettes a day you will erode the genetic material of most of the cells in your body, and thereby be at a significantly greater risk of cancer. "Before now, we had a large body of epidemiological evidence linking smoking with cancer, but now we can actually observe and quantify the molecular changes in the DNA due to cigarette smoking," says Ludmil Alexandrov, a theoretical biologist at Los Alamos National Labroratory and an author of the study.
 
The discovery means that people who smoke a pack of cigarettes a day for a year, develop on average, 150 extra mutations in every lung cell, and nearly 100 more mutations than usual in each cell of the voice box, 39 mutations for the pharynx, 23 mutations for mouth, 18 mutations for bladder, and 6 mutations in every cell of the liver.
 

Smoking causes cancers not exposed to smoke
 

Scientists were surprised to find that tobacco smoke caused mutations in tissues that are not directly exposed to smoke. While more than 70 of the 7,000 chemicals in tobacco smoke have long been known to raise the risk of at least 17 forms of cancer, the precise molecular mechanisms through which these chemicals mutate DNA, and give rise to tumours in different tissues have never been altogether clear, until now. The study showed that some chemicals from tobacco smoke damage DNA directly, but others found their way to different organs and tissues, and ramp up the natural speed at which mutations built up in the tissues in more subtle ways, often by disrupting the way cells function. The more mutations a cell acquires, the more likely it is to turn cancerous.
 

Why some smokers get cancer and others do not

“It won’t happen to me. . . . My grandfather started smoking when he was 11, smoked 20 a day, and lived ‘til he was 90”. We have all heard this before. But we now know why some smokers get cancer and others do not. it is because of the way mutations arise. When a person smokes, the chemicals they inhale create mutations at random points in the genome. Many of these changes will be harmless, but others will not be so benign. The more smoke a person is exposed to, the greater the chance that the accumulating mutations will hit specific spots in the DNA that turn cells cancerous. Even decades after people stop smoking, former smokers are at a long-term increased risk of developing cancers.“You can really think of it as playing Russian roulette,” says Alexandrov.
 

Takeaways

Until now, it has not been fully understood how smoking increases the risk of developing cancer in parts of the body that do not come into direct contact with smoke.
 
Sir Mark Walport, director of the Wellcome Trust, says that the findings from the research described above: “will feed into knowledge, methods and practice in patient care.” Dr Peter Campbell, from the Wellcome Trust Sanger Institute says: “The knowledge we extract over the next few years will have major implications for treatment. By identifying all the cancer genes we will be able to develop new drugs that target the specific mutated genes, and work out which patients will benefit from these novel treatments.”

• Stem cell study aims to improve prospects for lung cancer sufferers
• Professor Sikora suggests that lung cancer is associated with poverty
• Current therapies for lung cancer extend life by only a few months
• Lung cancer kills more people than any other cancer

       

    

Traditional therapies
 

• Oncologists increasingly use targeted agents directed at molecular features of cancer cells
• There is increased off label use of these new targeted agents without evidence to support the practice
• A landmark study concludes that off label use of targeted agents show no benefit and should be discouraged
• Professor Gabra, head of cancer at Imperial College, says more research is needed

Despite significant progress in cancer care over the past decade, there remain substantial challenges in the treatment of advanced cancers. This has increased off-label use of newer drugs based on molecular studies of tumours, largely without much evidence to support the practice.

A landmark clinical study, known as SHIVA, led by Christophe le Tourneau, a senior medical oncologist at the Institut Curie in Paris, raised expectations among both doctors and patients, because it is one of the first randomized studies to explore molecularly targeted agents applied outside their indicated use (off-label) among those with advanced cancers for whom standard therapies had failed.
 
Findings, published in Lancet Oncology, September 2015, concluded that, “off-label use of molecularly targeted agents should be discouraged,” since the study detected no improvement in survival rates when compared to treatments selected by clinicians that were not based on such sophisticated DNA profiling. 

What are the implications of the study’s negative findings for personalised medicine?

Christophe le Tourneau

In the videos below Le Tourneau describes the SHIVA trail and some of the challenges it faced.

   

   
    

The context

Cancer is a heterogeneous, complex, and challenging disease to treat. Tumours formerly categorized as a single entity on the basis of microscopic appearance are now known to be diverse in their molecular characteristics. Cancer chemotherapy is on an evolutionary path from non-specific cytotoxic drugs that damage both tumour and normal cells to targeted agents that are directed at unique molecular features of cancer cells, and aims to produce greater effectiveness with less toxicity.
 
Over the past decade our understanding of cancer and the basis of its treatment has been significantly changed by the advent of rapid and cheap DNA sequencing technology. The application of these sophisticated analytic techniques to arrive at a therapy for a particular cancer has been called “personalized oncology.” The idea of personalized cancer care based on molecular characteristics of the tumour promises to expand the boundaries of precision medicine. Numerous case reports and other observations have suggested that therapy targeted at molecular characteristics of a tumour can have significant beneficial effects.
 
These personalized therapeutic strategies have rendered traditional classifications of many cancers redundant, because they have advanced our understanding of the underlying biology and molecular mechanisms of specific cancers. Cancer is no longer considered a single disease entity, and is now being subdivided into molecular subtypes with dedicated targeted and chemotherapeutic strategies. The concept of using information from a patient's tumour to make therapeutic and treatment decisions has changed the landscapes of both cancer care and cancer research.
 

The SHIVA study

The SHIVA study, carried out at eight academic centres in France and conducted in 195 patients with metastatic cancer resistant to standard care, was a proof-of-concept, open-label, randomized controlled study. The patients were randomly assigned to receive either molecularly targeted agents (used off-label) chosen on the basis of the molecular profile of the tumour; or therapy based on the clinician's choice. The median follow-up period was 11.3 months. Findings showed a median progression free survival (PFS) of 2.3 months for patients receiving targeted therapy, versus 2.0 months for patients receiving therapy based on the clinician's choice.

"So far, no evidence from our randomised clinical trial supports the use of molecularly targeted agents outside their indications on the basis of tumour molecular profiling . . . . . Our findings suggest that off-label use of molecularly targeted agents outside their indications should be discouraged, and enrolment into clinical trials encouraged," says Le Tourneau and his colleagues.
 

More research required

Hani Gabra, Professor of Medical Oncology and Head of Cancer, Imperial College London says, "SHIVA is important because it is the first randomized study carried out in this complex area of matching drugs to genomic profiles of tumours. Despite the fact that the results are negative we should continue research in this area because personalised medicine is a relatively new area. One thing to note is that the molecularly targeted agents used in SHIVA were single agents, which could increase resistance and reduce the agent’s efficacy. In clinical practice we tend to use several targeted agents in combination in order to counteract drug resistance. SHIVA tested specific agents and specific targets, which resulted in disappointing findings. This doesn’t necessarily negate the overall strategy, but it does suggest that more research is necessary to test the overall strategy, and this might be more challenging.”
 

Takeaways

SHIVA is one of several on going and proposed studies aimed at defining the role of targeting sequencing of tumours in an endeavour to enhance therapy. The SHIVA study did not uncover any new positive evidence to help in the management of advanced cancers. Le Tourneau and his colleagues suggest further studies in a subset of patients that have tumours with molecular alterations in the chain of proteins in the cell that communicates a signal from a receptor on the surface of the cell to the DNA in the nucleus of the cell. Oncologists, while disappointed by SHIVA’S results, still hold out hope for their patients and advocate further studies.

• Cancer results when stem cells divide and mutate uncontrollably
• Whether this is predominantly the result of intrinsic or extrinsic factors is unclear
• Some experts say 65% of cancers result from intrinsic factors and are unavoidable
• Other experts say most cancers result from extrinsic factors and are avoidable
• Cancer strategy should not hide behind ‘bad luck’
• Resources need to be allocated more smartly to prevent cancer

Is cancer the result of bad luck and unavoidable, or is it self-inflicted and prevented by simple lifestyles choices? Two 2015 studies arrive at strikingly different conclusions.
 
One, carried out by researchers from the John Hopkins Kimmel Cancer Centre and published in January 2015 in the journal Science, suggests that two thirds of cancers result from bad luck. Another, carried out by researchers from the Stony Brook Cancer Centre in New York and published in December 2015 in the journal Nature rebuts the findings of the Science paper, and suggests that 70 to 90% of cancer risk is self-inflicted and therefore can be avoided.

Which is right? And, why should this concern us?
 

Cancer

Cancer is a complex group of diseases characterised by the uncontrolled growth and spread of abnormal cells. If this is not checked it can cause death. Nearly 80% of all cancer diagnoses are in people aged 55 or older. Some facts about cancer In 2015 around 1.7m new cancer cases were diagnosed in the US, and about 330,000 in the UK. Each year, there are some 589,430 cancer deaths in the US, and some 162,000 in the UK. The annual treatment cost of cancer for the US is about $90bn and for the UK about £10bn. The causes of cancer include genetic, and lifestyle factors; certain types of infections; and environmental exposures to different types of chemicals and radiation.  Whitfield Growdon, Oncology Surgeon at Massachusetts General Hospital and professor at the Harvard University Medical School describes cancer and the causes of cancer.


         

The Science paper: cancer is unavoidable

The Science paper found that 65% of cancer cases are a result of bad luck: random DNA mutations in tissue cells during the ordinary process of stem cell division; regardless of lifestyle and hereditary factors. The remaining 35% of cancer cases, say the authors, are caused by a combination of similar mutations and some environmental and hereditary factors. One implication of these findings is that preventative strategies will not make a significant difference to the incidence rates of most adult cancers. So accordingly, the optimal way to reduce adult cancers is early detection when they are still curable by surgery.
 
Stem cell division is the normal process of cell renewal, but the extent to which random cell mutations contribute to cancer incidence, compared with hereditary or environmental factors, is not altogether clear. This is what the John Hopkins researchers sought to address with their study. Scientists examined 31 tissue types to discover whether the sheer number of cell divisions increases the number of DNA mutations, and therefore make a given tissue more prone to become cancerous.
 
Researchers developed a mathematical model, which suggested that it is incorrect to assume that cancer may be prevented with “good genes” even though we smoke, drink heavily, and carry excess weight. Their study found that, "the majority [of adult cancer risk] is due to bad luck, that is, random mutations arising during DNA replication in normal, noncancerous stem cells."  And, "this is important not only for understanding the disease, but also for designing strategies to limit the mortality it causes," say the researchers.
 
According to the Science paper bad luck mutations account for 22 of 31 adult cancer types, including ovarian, pancreatic, bone and testicular cancers. The remaining nine, including lung, skin and colorectal cancers, occurred more often than the random mutation rate predicted. This suggests that in these cancers, either inherited genes or environmental factors have a significant influence on cases.
 
“Our study shows, in general, that a change in the number of stem cell divisions in a tissue type is highly correlated with a change in the incidence of cancer in that same tissue,” says Bert Vogelstein, Clayton Professor of Oncology at the John Hopkins University School of Medicine, and co-author of the study. One example, he says, is in colon tissue, which in humans, undergoes four times more stem cell divisions than small intestine tissue. Likewise, colon cancer is much more prevalent than small intestinal cancer.
 
In a BBC Radio 4 interview Cristian Tomasetti, co-author of the study said: “Let’s say my parents smoked all their lives, and they never got lung cancer. If I strongly believed cancer was only environment, or the genes that are inherited, then since my parents didn’t get cancer, I may think I must have good genes, and it would be OK to for me to smoke. On the contrary, our study says ‘no’, my parents were just extremely lucky, and played a very dangerous game.”

Related Commentaries

Liquid biopsies to detect pancreatic cancer are near 
Full circle in cancer research
Is immunotherapy a breakthrough in cancer treatment?
Is patient engagement the new blockbuster drug? 
We should give up trying cure cancer

The Nature paper: cancer is avoidable

In a BBC interview, Yusuf Hannun, Director of the Stony Brook Cancer Center, Joel Strum Kenny Professor of Cancer Research and one of the authors of the Nature paper, challenged the findings of the ‘bad luck’ study. He suggests that hiding behind ‘bad luck’ is like playing Russian roulette with one bullet; one in six will get cancer. "What a smoker does is add two or three more bullets to the revolver and pulls the trigger. Although there is still an element of luck, because not every smoker gets cancer, they have stacked the odds against themselves. From a public health point of view, we want to remove as many bullets as possible from the revolver," says Hannun.
 
The Nature paper rebuts the John Hopkins ‘bad luck’ thesis. Its lead author, Song Wu, from the Department of Applied Mathematics and Statistics at Stony Brook University, notes that the Science paper had not conducted an alternative analysis to determine the extent to which external risk factors contribute to cancer development, and it assumes that the two variables: intrinsic stem-cell division rates, and extrinsic factors, are independent. “But what if environmental factors affect stem-cell division rates, as radiation is known to do?” asks Wu.
 
Wu and his colleagues provide an alternative analysis by applying four analytical approaches to the data that were used in the earlier Science paper and arrive at a radically different conclusion: that 70 to 90% of adult cancer cases result from environmental and lifestyle factors, such as smoking, drinking alcohol, sun exposure and air pollution. Wu admits that some rare cancers can result from genetic mutations, but suggest that incidence rates of cancers are far too high to be explained primarily by mutations in cell division.
 
According to the Nature paper, if intrinsic risk factors did play a key role in cancer development, the total number of divisions in tissue stem cells would correlate with lifetime cancer risk, and the incidence rates of the disease would be less than it actually is. Wu and his colleagues analyzed the same 31 cancer types as in the earlier Science paper, and evaluated the number of stem cell divisions in each. They then compared these rates with lifetime cancer incidence among the same cancer types. This allowed them to calculate the contribution of stem cell division to cancer risk.
 
Wu et al also pursued epidemiological evidence to further access the contribution of environmental factors to cancer risk. They analyzed previous cancer studies, which show how immigrants moving from regions of low cancer incidence to regions with high cancer incidence soon develop the same tumor rates, suggesting that the risks are environmental rather than biological or genetic.
 
The researchers’ findings suggest that mutations during cell division rarely accumulate to the point of producing cancer, even in tissues with relatively high rates of cell division. In almost all cases, the Nature paper found that some exposure to carcinogens or other environmental factors would be needed to trigger disease, which again suggested that the risks of the most prevalent adult cancers are due to environmental factors. For example, 75% of the risk of colorectal cancer is due to diet, 86% per cent of the risk of skin cancer is due to sun exposure, and 75% of the risk of developing head and neck cancers is due to tobacco and alcohol.
 
The Nature paper concludes that bad luck, or intrinsic factors, only explain 10 to 30% of cancer cases, while 70 to 90% of adult cancer cases result from environmental and lifestyle factors. "Irrespective of whether a subpopulation or all dividing cells contribute to cancer, these results indicate that intrinsic factors do not play a major causal role," say the authors. This suggests that many adult cancers may be more preventable than previously thought. 
 

Preventing cancer 

Even the Science study concedes that extrinsic factors play a role in 35% of the most common adult cancers, including lung, skin and colorectal cancers. This, together with the Nature study, and the rising incidence of avoidable cancers, should be a wake-up call because a substantial proportion of cancers can be prevented.
 
Hannun is right! Whatever the causes of cancer, we should not ‘hide behind bad luck’.  We should act on evidence, which suggests that it is within everyone’s capabilities to make simple lifestyle changes that can prevent common adult cancers.  Although maintaining a healthy lifestyle is no guarantee of not getting cancer, the Nature paper underlines the fact that a healthy lifestyle stacks the odds in your favor.  The paper supports preventative cancer strategies.
 
In 2015, tobacco smoking caused about 171,000 of the estimated 589,430 cancer deaths in the US. The Nature paper suggests that the overwhelming majority of these could have been prevented. In addition, the World Cancer Research Fund has estimated that up to 33% of the cancer cases that occur in developed countries are related to being overweight or to obesity, physical inactivity, and/or poor nutrition, and thus could also be prevented.
 
It seems reasonable to suggest that the risk of cancer can be significantly reduced by: (i) a cessation of smoking, (ii) drinking less alcohol, (iii) protecting your skin from the sun, (iv) eating healthily, (v) maintaining a healthy weight, and (vi) exercising regularly.
 

The UK Position

Everyone understands the enormity of the burden of cancer, and what to do to reduce its risk. In the UK, as in other wealthy countries, there is no lack of money, no lack of resources, and no lack of expertise for cancer care. The annual spend on cancer diagnosis and treatment alone in the UK is about £10 billion. The UK also has a government appointed Cancer Czar charged with producing a national cancer plan to bring Britain's cancer survival rates up to those of European levels. Despite our understanding and all these resources, a 2014 study published in the Lancet suggests that cancer survival rates in the UK still lag more than 20 years behind many other European countries, and that people are dying needlessly.  Why is this?
 

Fear of preventative medicine 

Writing in The Times in January 2016, Sir Liam Donaldson, a former UK Chief Medical Officer, suggested that although preventative healthcare strategies are vital “to provide safe, high quality care without running out of money”, governments avoid helping the public to mitigate the risks of modern living, which can cause cancer, because of  “two primal political forces: the mortal dread of being labeled a ‘nanny state’, and a fear of removing people’s perceived pleasures.”
 
During Donaldson’s tenure between 1998 and 2010, the government rejected his recommendation for a minimum unit price for alcohol, and for the same reasons in 2014, the government rejected a tax on sugar recommended by Public Health England. Excess sugar increases the risk of cancer, heart disease and diabetes. According to Donaldson, without effective government action to lower the vast and escalating burden of cancer, and other chronic diseases, the NHS is unsustainable.
 
The missing link in preventative strategies is behavioral techniques that engage people who are at risk and help them change their behaviors. Such techniques have been demonstrated to be successful in both the UK and US. They explain how people behave, and encourage them to reduce unhelpful influences on their health, and change the way they think and act about important health-related issues such as diets, lifestyles, screenings and medication-management. See: Behavioral Science provides the key to reducing diabetes
 

Takeaway 

It is crucial that the UK government now embraces behavioral techniques to curb the curse of cancer.  Donaldson is right: if cancer, and other chronic diseases, which together consume the overwhelming percentage of healthcare expenditure, are not prevented the NHS will become unsustainable.

• Detecting pancreatic cancer early is a significant advance
• 80% of people with pancreatic cancer are diagnosed late
• Only 3% of pancreatic cancer patients survive 5 years after diagnosis
• 12% of pancreatic cancer is associated with obesity
• MD Anderson blood test is 100% accurate at detecting pancreatic cancer
• Urine test 90% accurate at detecting pancreatic cancer
• Both tests could be in the clinic in a few years

Liquid biopsies are poised to detect pancreatic cancer early, which is a significant advance.

This is important because the clinical symptoms arise late in people with this cancer. Eighty per cent of people with the disease are diagnosed when it has already spread, so they are not eligible for surgery to remove the tumour, which currently is the only potential cure. Only about 3% of patients diagnosed with pancreatic cancer survive five years after diagnosis.
 

The pancreas is an organ that sits close behind the stomach, and has two main functions: (i) producing digestive enzymes, which break down food so that it can be absorbed, and (ii) producing insulin, which regulates blood sugar levels. Pancreatic cancer occurs when cells are produced in the pancreas in an uncontrolled fashion. This can lead to a number of health risks. Almost half of all new cases of cancer of the pancreas are diagnosed in people aged 75 and over, and is uncommon in people under 40. This year, an estimated 48,960 adults in the US and some 9,000 in the UK will be diagnosed with pancreatic cancer. It is estimated that 40,560 US deaths, and about 9,000 deaths in the UK from this disease also will occur this year. Those at higher risk include people with a family history of the cancer, heavy smokers, and obese people. There is some suggestion that pancreatic cancer is a risk for people over 50 who are newly diagnosed with diabetes.
 

Pancreatic cancer and diabetes

Type-2 diabetes is considered to be associated with pancreatic cancer, but it is not altogether clear whether diabetes is a risk factor or a symptom. Two studies published in 2011; one in the British Journal of Cancer, and the other in the Annals of Oncology confirm the hypothesis that, “increased BMI and abdominal obesity are associated with increased pancreatic cancer risk.” One of the studies estimates that about 12% of all pancreatic cancers in the UK are attributable to overweight and obesity. Fatty tissue in overweight people produces more hormones and growth factors than those in people of a healthy weight. High levels of some of these hormones, including insulin, which is produced in the pancreas, can increase the risk of pancreatic cancer.

Dr Roni Sharvanu Saha, a consultant in acute medicine, diabetes and endocrinology at St George's Hospital, London, opines on the possible relationship between diabetes treatment and pancreatic cancer, and says that, “the jury is out” about the link. 


            
                

Blood test for pancreatic cancer 

Pancreatic cancer is devastating, it usually shows no signs or symptoms, and presents late. Being able to detect the disease early is considered life enhancing for patients. Scientists from the University of Texas MD Anderson Cancer Center believe they are close to developing a blood test to detect pancreatic cancer, which they describe as "a major advance". Early results, published in 2015 in the journal Nature, showed the test was 100% accurate. Experts said the findings were striking and ingenious, but required refinement before they could be used in the clinic.
 

Major advance

A wall of fat marks the boundary of every cell in the human body. The MD Anderson test hunts for tiny spheres of fat, called exosomes, which are shed by the cancers. Scientists looked for unique signatures of cancer in these fatty exosomes, and noticed that a protein called proteoglycan glypican-1 was found in much higher levels in people with pancreatic cancer. Further blood tests on 270 people showed it was 100% accurate at distinguishing between cancers, other pancreatic disorders and healthy tissue.

The need for such a test is huge. According to Dr Raghu Kalluri, one of the MD Anderson researchers, the test is, "not too far" from the clinic. "We think the ability to identify and isolate cancer exosomes is a major advance and provides the possibility of immensely benefiting our patients," says Kalluri.
 

Urine test for pancreatic cancer

Scientists from Barts Cancer Institute, Queen Mary College, London, have developed a simple urine test to detect pancreatic cancer. The UK-Spanish study, published in Clinical Cancer Research in 2015, showed that out of 1,500 proteins found in the urine samples of 500 people, three were seen to be at much higher levels in the pancreatic cancer patients. This provided a "protein signature" that could identify the most common form of the disease, and distinguish between this cancer and the inflammatory condition chronic pancreatitis, which can be hard to tell apart. The signature was found to be 90% accurate. More research is now planned, and scientists will focus particularly on people whose genes put them at particular risk of pancreatic cancer.
 

Advantages of urine over blood 

Lead researcher, Dr Tatjana Crnogorac-Jurcevic, said: "We've always been keen to develop a diagnostic test in urine as it has several advantages over using blood. It's an inert and far less complex fluid than blood, and can be repeatedly and non-invasively tested.  We're hopeful that a simple, inexpensive test can be developed, and be in clinical use within the next few years."

"For a cancer with no early stage symptoms, it's a huge challenge to diagnose pancreatic cancer sooner, but if we can, then we can make a big difference to survival rates," says co-author and Director of Barts Cancer Institute, Professor Nick Lemoine.
 

Takeaways

Although there is a significant amount of work still to do before these tests appear in clinics, the levels of accuracy reported by the researchers are striking, and suggest that, in principle, a liquid biopsy has been found for this devastating cancer, which is good news for patients suspected of having the disease.

• The scientific framework for understanding cancer has gone full circle
• Cancer research is back where it began 60 years ago
• Cancer mutations outsmart the smartest scientists
• Challenges for cancer treatment go beyond biological complexity 

After sixty years of cancer research we’re back where we started. That’s according to MIT cancer scientist Professor Robert Weinberg, known for his discoveries of the first human oncogene (a gene that causes normal cells to form tumors), and the first tumor suppressor gene.

Writing in the journal Cell in 2014, Weinberg argues that, in the 1950s scientists viewed cancer as, “An extremely complicated process that needed to be described in thousands of different ways.” Then, scientists believed viruses caused cancer, which was proved wrong. In the 1980s cancer scientists developed the notion that the disease was caused by mutant genes. “This gave . . . the illusion . . . that we would be able to understand the laws of cancer formation the way we understand, with some simplicity, the laws of physics," says Weinberg. This was not the case. Over the past decade, scientists have returned to where they started in the 1950s, and view cancer as an extremely complex disease, “We are once again caught in this quandary: how can we understand this complexity in terms of a small number of underlying basic principles?", asks Weinberg.
 

Each cancer is unique

Victor Velculescu, Professor of Oncology at Johns Hopkins University, and internationally known for his discoveries in cancer genomics, stresses the uniqueness of cancer. “Between everybody that has cancer today, to everybody that's probably ever had cancer since the beginning of humankind, [each person] has had different molecular alterations in this disease,” he says. Adding to cancers complexity is the fact that the disease mutates over time, which means that people become resistant to specific drugs, and clinicians are obliged to search for other treatments. Professor Axel Walther, Consultant Medical Oncologists and Director for Research in Oncology at University Hospitals, Bristol describes the challenges of drug resistance for cancer patients:

     
 

Pathways

A significant advance in cancer treatment is the notion that random “errors” in our genes, which cause cancer could be simplified into specific pathways, which are the “rail tracks” within cells along which chemicals flow that keep cells alive and functioning. Genes are “stations” along these pathways. There are thousands of pathways, some known and others, unknown, and their breakdown causes cancer. Discovering these pathways provides an opportunity to block the progress of cancer, with appropriate drugs.

Professor William Nelson, a recognized leader in cancer research, and Director of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, says, the complexity of cancer means that, “Only rarely can a single drug block a single pathway.” Most cancers require a combination of drugs. Walther describes the challenges that the complexity of cancer pose for personalised medicine:

   
 

Cost factor

Challenges in cancer treatment go far beyond biological complexity. Increasingly, the cost of drugs is an important factor. Dr. Richard Pazdur, the FDA’s Cancer Czar, questions how much longer the FDA can remain blind to drug prices, and the growing debate over how to place an appropriate value on cancer drugs, which can cost US$100,000 or more a year. Earlier this year NHS England withdrew funding for 25 cancer drugs because the costs were too high.
 

Takeaways

Weinberg is not defeated by the notion that the scientific framework for understanding cancer has come full circle. Over the past 60 years of cancer research, many ideas have flowed from laboratories, and led to incremental advances in treating cancer, and this will continue.

• Experts describe new prostate cancer study as the disease’s ‘Rosetta Stone’

• Prostate cancer kills nearly 11,000 men each year in the UK alone

• Men with untreatable prostate cancer could benefit from standard drugs

• Study opens black box of genetics to treat previously untreatable cancer

• Mediterranean diet lowers mortality risk for men with prostate cancer

A new UK-US cancer study could transform prostate cancer treatment, and give hope to sufferers whose cancers have become resistant to treatment. Experts’ hail the study as “incredibly exciting and ground breaking”. According to Professor Johann de Bono, of the Institute of Cancer Research, London, who led the British team, the study opens up a new era of treatment, in which men will be given drugs tailored to their tumours. 

Cancer is lethal when it metastasises and becomes resistant to drugs. The study, published in the journal Cell in 2015, involved 150 men close to death whose prostate cancers had spread throughout their bodies, and were not responding to available drugs. 
     

Prostate cancer’s ‘Rosetta Stone’

The research has opened up a black box in cancer genetics, and changes the way we think about and treat prostate cancer. Now that doctors have a map of which mutations to look for, they could search for them using a £200 test. 

De Bono, extracted samples of the cancer from metastatic tumors, and analysed their DNA, which showed that 90% of the men carried genetic mutations in their tumors, which matched drugs already on the market. A third of the men studied had tumors suitable for treatment with new drugs called PARP inhibitors.

‘’We're describing this study as prostate cancer's Rosetta Stone because of the ability it gives us to decode the complexity of the disease, and to translate the results into personalised treatment plans for patients. What's hugely encouraging is that many of the key mutations we have identified are ones targeted by existing cancer drugs - meaning that we could be entering a new era of personalised cancer treatment," says de Bono.

According to de Bono, “We are changing how long these men are living. This gives me hope that I can make a difference for men dying of prostate cancer. There is still a lot of work to do. This is not a cure, but it is a huge step forward.” 
 

Prostate cancer

In an earlier Commentary we discussed the dilemmas men face when they have been diagnosed with prostate cancer. Prostate cancer is the most common cancer in men, and each day in the UK alone 110 men are diagnosed with the disease. Cancer begins to grow in the prostate, a gland in the male reproductive system, and develops slowly. Although it can be cured if diagnosed early, there may be no signs that you have it for many years, and symptoms often only become apparent when your prostate is large enough to affect the urethra. Here cancer expert Professor Karol Sikora describes the symptoms of advanced prostate cancer:

         
             
Once prostate cancer begins to spread it becomes difficult to treat, and each year nearly 11,000 men die of the disease in the UK. Treatment options include watchful waiting, surgery, radiation, hormone therapy, chemotherapy, biological therapy and bisphosphonate therapy.
 

Mediterranean diet

According to research published in the journal Cancer Prevention Research, a Mediterranean diet rather than a Western diet may improve survivorship for men diagnosed with prostate cancer.

This is welcome news because there is a dearth of evidence to counsel men living with prostate cancer on how they can modify their lifestyle to lower the risk of mortality. The new study from Harvard’s Chan School of Public Health, investigated the diets of 926 men with prostate cancer for an average of 14 years after their diagnosis, and in 2015 published their findings, which suggest that people living with prostate cancer who ate a predominantly Western diet, high in red and processed meat, fatty dairy foods, and refined grains, were two-and-a-half times more likely to die from prostate cancer, and had a 67% increased risk of all-cause mortality, compared with participants who followed a Mediterranean diet, rich in vegetables, fruits, fish, whole grains, and healthy oils. In comparison, men who follow a Mediterranean diet had a 36% lower risk of all-cause mortality.

Lead author Meng Yang suggests treating the findings cautiously, "Given the scarcity of literature on the relationship between post-diagnostic diet and prostate cancer progression, and the small number of disease-specific deaths in the current study.”
 

Dietary supplements and vitamins

Researchers continue to look for foods (or substances in them) that can help lower prostate cancer risk. Scientists have found some substances in tomatoes (lycopenes) and soybeans (isoflavones) that might help prevent prostate cancer. Studies are now looking at the possible effects of these compounds more closely. Scientists are also trying to develop related compounds that are even more potent, and might be used as dietary supplements. 
 

Takeaways

Some studies suggest that certain vitamin and mineral supplements (such as vitamin E and selenium) might lower prostate cancer risk. But a large study of this issue, called the Selenium and Vitamin E Cancer Prevention Trial (SELECT), found that neither vitamin E nor selenium supplements lowered prostate cancer risk after daily use for about five years. In fact, men taking the vitamin E supplements were later found to have a slightly higher risk of prostate cancer.

De Bono’s breakthrough in cancer genetics means that many men whose prostate cancer was thought untreatable could be given drugs that are already on hospital shelves. Some patients have already benefited, and are alive more than a year on, despite only having been given weeks to live.

• Immunotherapy drugs heralded as game changing cancer treatment

• MD Anderson Professor Allison stripped cancer’s ability to evade attack

• Nivolumab focuses on the environment around a cancer

• Immunotherapy drugs are too expensive as sustainable treatments

• The future is personalized medicine says cancer expert Karol Sikora

A new drug class that neither directly treats nor kills cancer is heralded as a game changer in cancer treatment. 
 

New hope for late stage cancer patients

In March 2015, the American Food and Drug Administration (FDA) awarded an expanded approval for Opdivo (nivolumab), to treat non-small-cell lung cancer, which is the most common type of lung cancer, and means lung cancer patients who have failed other therapies and have no other treatment options, have another shot at containing their tumors. In June 2015, the European Commission approved the same Bristol-Myers Squibb drug in a fast track assessment for previously treated advanced melanoma patients.

Accelerated assessment was given in Europe because Opdivo (nivolumab) qualified as a “Medicinal product of major interest from the point of view of public health, and in particular from the viewpoint of therapeutic innovation.” 

FDA and EU approvals of the drug Opdivo, opens the door for other, next-generation immunotherapies to treat advanced cancers. These are heralded as a new class of game changing drugs. But are they? 
 

The genesis

Because cancer is a result of your body’s own cells growing abnormally, your immune system is held back from recognising cancer as foreign and potentially harmful. This is important because without such checks your immune system would kill you.  

Professor James Allison, director of MD Anderson’s immunotherapy platform, which cultivates, supports and tests new developments of immunology-based drugs and combinations, is credited with ground-breaking research that stripped away cancer’s ability to evade attack by the immune system. Allison’s discoveries led to nivolumab to improve the survival rate of patients with metastatic melanoma, and his insights into the basic biology of immune system T cells is broadly applicable to a variety of cancers. 
 

How it works

These new drugs release the body’s own weapons: killer white blood cells called T cells, and have been likened to taking the brakes off the immune system so that it is able to recognise tumors it wasn't previously recognising, and react to destroy them.

Unlike traditional cancer therapies such as surgery, chemotherapy, radiation or the anti-cancer drugs, immunotherapy does not target the tumor itself. Instead, it focuses on the environment around the cancer, and releases a check on the immune system’s appetite for anything that it does not recognize, so the body’s own defences can recognize tumor cells as targets. Allison says, “This drug doesn’t treat cancer; it doesn’t kill cancer cells so you can’t inject it and expect cancer to melt away immediately because it won’t.” 

However, when nivolumab is combined with tumor-targeted treatments, it lowers the risk of recurrent cancers. It does this by training the body’s T cells to recognize specific features of tumors, just as they do for viruses and bacteria. Thus, the immune system itself is programmed to destroy any returning or remaining cancer.
 

Too costly

Although immunotherapies are generating excitement among cancer clinicians and researchers, clinical studies on melanoma patients show relatively modest prolongations of life, compared with historical norms, at significant costs. For example, the cost of Opdivo (nivolumab) for one patient is about £100,000 per year.

Speaking at the 2015 American Society of Clinical Oncology (ASCO) conference in Chicago, Dr Leonard Saltz from Memorial Sloan Kettering Cancer Center, New York City, suggested that new immunotherapies would cost more than US$1 million per patient per year at the higher dose currently being studied in many different cancer types, and warned, "This is unsustainable.... We must acknowledge that there must be some upper limit to how much we can, as a society, afford to pay to treat each patient with cancer . . As someone who worries about making cancer care available to everyone and minimizing disparities, I have a major problem with this: these drugs cost too much."
      

Takeaway

According to cancer expert Professor Karol Sikora the future of cancer treatment is personalized medicine rather than new immunotherapy products. Personalized cancer care takes into account the individual’s disease, and their personal circumstances. According to Sikora, “The extent to which treatment can be tailored to an individual has been limited by crude descriptions of their disease, and generic treatment options. Advances in genomics and drug responsiveness are leading to more detailed descriptions of a patient’s cancer and better-targeted treatments, which offer significant advantages over blunderbuss chemotherapies. Personalised medicine is the real future for all our patients. Forget the drug hype; this is where the real hope lies”. 

Here Mike Birrer, Professor of Medicine at the Harvard University Medical School, and Director of the Cancer Center at Massachusetts General Hospital describes personalised medicine: