Prostate cancer is not insignificant in terms of numbers: 217,730 Americans will be diagnosed with prostate cancer this year and 32,050 will die from the disease, according to the American Cancer Society.
Results of a recent study published online in the Journal of the National Cancer Institute have raised concerns about the link between treatment for prostate cancer and increased risk for those men who may go on to develop colorectal cancer.
Androgen deprivation therapy is a common type of treatment for prostate cancer that involves blocking the male hormone testosterone through either surgical removal of the testicles or a series of injections. It’s been shown to benefit men with advanced cancers, but its benefit for less-advanced disease is unclear.
This study is large scale as researchers looked at data from 107,859 men aged 67 and older with prostate cancer in the USA. They were identified through the Surveillance, Epidemiology and End Results and Medicare linked database, which provides information about older adults with newly diagnosed cancer.
Vahakn B. Shahinian, M.D., M.S., assistant professor of internal medicine at the University of Michigan Medical School and a member of the U-M Comprehensive Cancer Center led the study. The researchers found that the risk increased the longer a man received androgen deprivation therapy. Patients who had their testicles removed, a procedure called orchiectomy, had the highest rates of colorectal cancer.
Overall, the risk of colorectal cancer was still low – less than 1 percent per year even among orchiectomy patients. But any increased risk should be carefully considered when using androgen deprivation therapy in cases when its benefit is not clear, the researchers say.
There is no suggestion that androgen deprivation therapy should be stopped as it can be lifesaving for certain men with prostate cancer, and those patients should not hesitate to use it. However, what is imperative is that men on this therapy should have continued routine preventive care, including colorectal cancer screening, as part of their treatment.