Important observations' from large CPS-II nutrition cohort
Ask most people the biggest public health crisis, other than the Covid-19 virus, that impacts people with cancer; they will say it is smoking. This is true, but obesity is set to overtake smoking as the leading cause of preventable cancer deaths in the United States.
In prostate cancer, some but not all observational studies have found that obesity measured during the first 12 months after diagnosis may be associated with worse prostate cancer-specific outcomes. However, we have little understanding of outcomes about the impact of obesity or weight change after diagnosis.
Using data from 8,330 men in the Cancer Prevention Study-II Nutrition Cohort, Troeschel and colleagues evaluated how body mass index (BMI) and weight gain after a prostate cancer diagnosis affect prostate cancer-specific cardiovascular all-cause mortality. They concluded an association between obesity after a prostate cancer diagnosis and prostate cancer mortality; however, this association was not statistically significant.
They also found that post-diagnosis obesity was significantly associated with prostate cancer-specific mortality in men with lower-risk tumors. Furthermore, men who gained more than 5% of their body weight or more than 10 lb after diagnosis had a higher risk of prostate cancer mortality than men who maintained a stable weight. Since men with low-risk tumors have a long life expectancy after diagnosis and treatment, special heed to this is essential.
This leads us to the next important question, if obesity and weight gain are risk factors for prostate cancer mortality, is weight loss protective? We don’t know the answer to this critical question.
Several ongoing trials are evaluating the impact of weight loss on outcomes after prostate cancer treatment such as the WARRIOR (Weight Management Aimed to Reduce Risk and Improve Outcomes From Radical Prostatectomy) study and the EMPOWeR (Evaluation and Management for Prostate Oncology, Wellness, and Risk) study.
In the interim, we should be mindful of any weight gain.
Peter E. Lonergan, MD, FRCS (Urol), is a urologic oncology clinical fellow in the Department of Urology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco.
