Obesity and weight gain contribute to risk of prostate cancer recurrence after prostatectomy, especially in inactive men, according to results of a retrospective cohort study, presented at the American Association for Cancer Research 101st Annual Meeting 2010.

Corinne E. Joshu, a postdoctoral fellow in the department of epidemiology at Johns Hopkins Bloomberg School of Public Health in Baltimore and colleagues followed 1,337 men with clinically-localized prostate cancer who underwent prostatectomy between 1993 and 2006. Participants completed a survey on dietary, lifestyle and medical factors (i.e. weight, height, physical activity and sedentary behavior) five years before surgery and one year after.

By the end of follow-up in 2008, 102 men had prostate cancer recurrence. Men whose cancer had recurred were older, more likely to have poorer pathological tumour characteristics and were less likely to have a family history of prostate cancer than men whose cancer did not recur.

"Weight gain of at least five pounds five years before surgery, to one year after surgery was associated with a nearly two-fold increased of prostate cancer recurrence compared with men who maintained their weight," said Joshu.

At five years prior to prostatectomy, 54 percent of the men were overweight and 9 percent were obese; among men who gained at least five pounds, the average weight gain was about 10 pounds by one year after surgery, according to Joshu. Obesity after surgery was associated with about a 1.7-fold increased risk.

"Our message is consistent with public health messages that are given for chronic conditions and other types of cancer: it is best for men to avoid weight gain or obesity, especially as they age - including men with prostate cancer," said Joshu.

Source: The American Association for Cancer Research