Obese men with prostate cancer are at higher risk for treatment failure after primary radiation therapy, according to a new study.
Published in the August 1, 2006 issue of CANCER, a peer-reviewed journal of the American Cancer Society, the study reveals that each incremental increase in body mass index (BMI) increased the risk for clinical or biochemical failure. The study is the first to investigate the association between obesity and post-radiotherapy outcome.
Evidence has increasingly shown that obesity has a deleterious effect on the human body, from the risk of diabetes to joint disease. Obesity has more recently been shown to play a significant role in the development of some cancers, including cancers of the breast, prostate, colon, and many others. Obesity has also been associated with the progression of disease. Obese men with prostate cancer often have more aggressive disease and higher mortality rates. Researchers postulate that fat tissue influences concentrations of various significant signaling molecules, such as testosterone, estrogen, insulin and insulin-like growth factor, which play a role in prostate cancer development and progression.
There is already a body of scientific evidence demonstrating that obesity is linked to treatment failure after prostatectomy. However, there are no data on the effects of obesity on the effectiveness of radiation treatment for prostate cancer. Sara Strom, Ph.D. of the University of Texas M. D. Anderson Cancer Center in Houston and colleagues reviewed the medical records of 873 patients who received radiotherapy alone for prostate cancer. Among the group, 18 percent were mildly obese and 5 percent were moderately to severely obese.