Recurrence risk doubled for men who gained weight after prostatectomy

AACR 101st Annual Meeting

Obese men and men who gained weight after prostatectomy were found to be at increased risk for prostate cancer recurrence. Researchers said the risk was even greater for men who are sedentary or inactive.

Corinne E. Joshu, MPH, PhD, a postdoctoral fellow at Johns Hopkins Bloomberg School for Public Health, presented the results of a retrospective cohort study at the AACR 101st Annual Meeting.

“Weight gain may increase the risk for prostate cancer recurrence after prostatectomy,” she said. “Obesity, especially in inactive men, may also increase the risk.”

Joshu and colleagues reviewed files of about 1,300 men treated by a surgeon at Johns Hopkins from January 1993 to March 2006. None of the patients had undergone prior hormone or radiation therapy. Each man still living in the United States as of November 2007 received a survey on dietary, lifestyle and medical factors, including weight, height, physical activity and sedentary behavior five years before surgery and one year after surgery.

At the time of prostatectomy, men who recurred (n=102) were older (58.1 years vs. 56.3 years; P=.007), more likely to have poorer pathological tumor characteristics and less likely to have a family history of disease (14.7% vs. 27.7%; P=.013) compared with men who did not recur (n=1,235). Five years before surgery, 54% of men in the cohort were overweight and 9% were obese.

Compared with men who had stable BMI, those whose BMI increased by at least 1 kg/m² from five years before surgery to one year after surgery had twice the risk for recurrence (HR=2.18, 95% CI 1.24-3.81). Men who were obese one year after surgery were 1.67 times (95% CI 0.91-3.04) more likely to recur compared with men with normal BMI.

In men who were classified as sedentary (>20 hours per week sitting), the risk for recurrence was even stronger (HR=2.65, 95% CI 1.09-6.47). Similarly, men classified as inactive, (>5 hours per week of leisure time activity) also at increased risk (HR=2.30, 95% CI 0.94-5.62).

In contrast, obesity one year after surgery was not associated with recurrence in men who were not classified as sedentary (HR=0.89, 95% CI 0.36-2.21), or in those who were considered active (HR=1.09, 95% CI 0.45-2.69).

“By avoiding obesity and weight gain, men with prostate cancer may be able to both prevent recurrence but also improve their overall well-being,” Joshu said.

This is more evidence that insulin and/or insulin-like growth factors 'feed' cancers.

– Harry S. Jacob, MD

HemOnc Today Chief Medical Editor

For more information:

Joshu CE. #883. Presented at: AACR 101st Annual Meeting; April 17-21, 2010; Washington, D.C.

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