Studies on whether obesity is linked with an increased risk of prostate cancer death post-radical prostatectomy are conflicting.
Researchers at the Kaiser Permanente Southern California's Department of Research & Evaluation examined data from three large health plans to evaluate if an increased body mass index (BMI) at prostate cancer diagnosis is related to prostate cancer mortality.
This new study included 751 men with prostate cancer who underwent radical prostatectomy. Researchers evaluated the link between BMI at the time of diagnosis and prostate cancer mortality, adjusted for Gleason score, PSA, tumor characteristics, and matching factors.
For the study Dr. Reina Haque, PhD, MPH, at Kaiser Permanente Southern California's Department of Research & Evaluation and lead author of this study along with colleagues divided participants into groups based on BMI; healthy (18.5–24.9), overweight (25–29.9) and obese (≥30).
Almost 43% of the participants had a BMI ≥25 at diagnosis, 30% were obese compared to the control group, 22%.
Overall, the results showed obese men had more than a 50% increase in prostate cancer mortality when compared to men with healthy BMI. . Men with high Gleason scores and the highest association between BMI and death, specifically men with Gleason scores of 8 or higher. The Gleason score ranges from 2 to 10, with the highest number representing the greatest likelihood of tumor cells spreading.
In a public release Dr. Haque stated "We found among patients undergoing surgical treatment for prostate cancer, weight at time of diagnosis is more strongly correlated with prostate cancer survival than many other factors researchers have studied in the past, including some prostate cancer treatments.” "Moving forward, we are hoping future studies will examine the effect of weight loss and other lifestyle modifications on prostate cancer mortality."
In their conclusion the team writes “These results suggest that BMI at diagnosis is strongly correlated with prostate cancer mortality, and that men with aggressive disease have markedly greater odds of death if they are overweight or obese.”
Additional studies are needed to determine which lifestyle modifications, such as diet or exercise, could prolong a prostate cancer patient's life. Further investigation also is needed to determine if the findings of this study, which looked at men who had prostate cancer surgery, apply to men who received other treatments such as radiation or hormone therapy.
Prior studies have examined the link between men’s weight at the time of diagnosis and the likelihood of survival however, many of those studies had been limited by self-reported body weight data or it was unclear when the BMI data were obtained, so the link between prostate cancer and mortality remained conflicted.
The manner in which this study was conducted had been different due to the fact the researchers had used medical records collected for the BMI. The researchers identified men who died of prostate cancer and compared their BMI at time of diagnosis to controls to determine if body weight is related prostate cancer death.
This study appears in the journal Obesity Research and Clinical Practice.
According to the American Cancer Society “Prostate cancer is the most common type of cancer found in American men, other than skin cancer. Prostate cancer is the second leading cause of cancer death in men, behind only lung cancer. One man in 6 will get prostate cancer during his lifetime. And one man in 36 will die of this disease.”
“Prostate cancer can be a serious disease, but most men found to have prostate cancer do not die from it. In fact, more than 2.5 million men in the United States who have had prostate cancer at some point are still alive today.”