Full circle in cancer research
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:
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:
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.
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.