Study: After a Diagnosis of Prostate Cancer, Men Who Have Obesity or Who Gain 10+ Pounds Are More Likely to Die from All Causes

Researcher: Ying Wang, PhD
Institution: American Cancer Society
Area of Focus: Epidemiology Research, Surveillance & Health Equity Science

The Challenge: Survivors of prostate cancer may have a higher risk of death for up to 15 years after diagnosis.

Previous studies suggest that men who have obesity before a diagnosis of prostate cancer or who have obesity during the first year after diagnosis may have a higher risk of dying specifically from prostate cancer.

Since men can’t do anything to change their previous behavior, and since the treatment of a cancer may influence body weight, it might be the most helpful to offer recommendations about weight for survivors beyond the first year after a diagnosis of prostate cancer.

But so far only 2 studies have examined the effect of gaining weight or developing obesity after a diagnosis of prostate cancer, and their results conflict.

The Research: Ying Wang, PhD, led an American Cancer Society (ACS) study using data from the Cancer Prevention Study II Nutrition Cohort about nearly 12,000 men who were diagnosed with prostate cancer between 1992 and 2013 and whose cancers had not spread. Those men were followed through December 2016 to collect information about the cause of any deaths that occurred.

Wang and research colleagues from Emory University and the ACS found further evidence to support that:

  • Developing obesity after a diagnosis of localized prostate cancer was linked with a higher risk of death from all causes, as well as death from cardiovascular disease, and possibly from prostate cancer. (This was the first study to look at the link between postdiagnosis BMI and weight change with cardiovascular disease among survivors of prostate cancer.)
  • Men who gained more than 5% of their body weight or more than 10 lbs. after a diagnosis of prostate cancer were more likely to die of prostate cancer and all causes than men who maintained their weight.

Most of the prostate cancer survivors in Wang’s study were elderly and White, so results may not be generalizable to people who are non-White or younger.

Why Does It Matter? Survivors of prostate cancer are advised to maintain a healthy weight and avoid weight gain, and Wang’s findings provide additional evidence to follow these recommendations. However, this study did not support promotion of weight loss among prostate cancer survivors—such suggestions require more research.