December 6, 2005

Obesity increases risk of prostate cancer relapse

NEW YORK (Reuters Health) - After surgery to remove a
cancerous prostate, the malignancy is more likely to recur
among obese men than in those of normal weight, a new study

The effect of obesity on prostate cancer incidence and
recurrence is "controversial," Dr. Christopher J. Kane of the
University of California at San Francisco and colleagues say in
the medical journal Urology. However, they note, two recent
look-back studies found recurrence of the disease was more
common among obese men.

To investigate this further, the researchers evaluated data
on 2,131 men who had undergone radical prostatectomy, i.e.,
removal of the prostate. Twelve percent of men developed
recurrent disease during follow-up over an average of 23

There was a significant association between body mass index
(BMI) and disease recurrence after factoring in the effect of
ethnicity, age and other conditions, the researchers found.

Men with BMIs of 35 or greater were 69 percent more likely
to have recurrence of prostate cancer than men whose BMIs were
25 or less (normal weight). Men with BMIs greater than 30 had a
31 percent increased risk of recurrence than men with lower

There are a number of potential mechanisms through which
obesity could promote prostate recurrence, the researchers
note, from the effect of excess fat on hormone levels to the
difficulty of operating on obese patients.

"Obese individuals undergoing radical prostatectomy require
vigilant follow-up care," the researchers write.

"Continued research is necessary," they add, "to evaluate
the efficacy of other treatments in obese patients with
prostate cancer, as well as to clarify how prostate cancer
recurrence affects survival in obese patients."

SOURCE: Urology, November 2005.