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 shows.
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 months.
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 BMIs.
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.”