Screening for Prostate Cancer


While with most cancers, early detection increases the chance of a cure; it is unclear whether screening for prostate cancer reduces the number of deaths from this disease. Despite the controversy, it is still recommended that men undergo annual screening for this disease utilizing digital rectal examination (DRE), PSA blood test or transrectal ultrasonography. Currently, it is recommended that men begin annual screening with PSA and DRE at age 50 and that men from Afro Caribbean origin and men with a strong family history of prostate cancer begin annual screening at age 45. 

The combination of detail gained by the PSA and DRE together improves the chance of identifying prostate cancer at an early stage.

  • Digital Rectal Exam (DRE): During a digital rectal exam (DRE), a physician inserts a gloved finger into the rectum to assess the texture and size of the prostate. If there are any abnormalities in the texture, shape or size of your gland, you may need more tests. 

  • PSA Blood Test: A simple blood test allows laboratory technicians to determine PSA levels. PSA is a protein that is normally secreted and disposed of by the prostate gland. Its function is involved in liquefying sperm. 

    It's normal for a small amount of PSA to enter your bloodstream. However, if a higher than normal level is found, it may be an indication of prostate infection, inflammation, benign prostate enlargement, or cancer. In patients with a known diagnosis of prostate cancer, the PSA level roughly reflects the total amount of cancer. The higher the PSA level , the more likely that the cancer is advanced.

  • Transrectal Ultrasonography: During transrectal ultrasonography, a small probe is inserted into the rectum. The probe emits high frequency sound waves that bounce off the prostate and produce echoes. A computer uses these echoes to create a picture called a sonogram that can show abnormal areas.

  • Prostate biopsy: If initial test results suggest prostate cancer, a biopsy may be recommended. To do a prostate biopsy, a small ultrasound probe is inserted into the rectum. Guided by images from the probe, a fine, spring-propelled needle retrieves several very thin sections of tissue from the prostate gland. This is done under local anaesthetic. 

    A pathologist who specializes in diagnosing cancer and other tissue abnormalities evaluates the samples. From those, the pathologist can tell if the tissue removed is cancerous and estimate how aggressive the cancer is.

Cancer that is removed by surgical resection or needle biopsy will be classified according to the Gleason Grading System for prostate cancer. This grading system, on a scale of 2-10, helps physicians predict how rapidly the cancer is likely to spread. The tissue samples are studied, and the cancer cells are compared with healthy prostate cells. The more the cancer cells differ from the healthy cells, the more aggressive the cancer and the more likely it is to spread quickly. 

The pathologist identifies the two most aggressive types of cancer cells when assigning a grade. The most common scale used to evaluate prostate cancer cells is called a Gleason score. Based on the microscopic appearance of cells, individual ratings from 1 to 5 are assigned to the two most common cancer patterns identified. These two numbers are then added together to determine your overall score. Scoring can range from 2 (nonaggressive cancer) to 10 (very aggressive cancer). 

Generally, higher Gleason scores are associated with more advanced and more rapidly growing cancers than lower scores.

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