Overweight or obese men diagnosed with prostate cancer are at greater risk of dying of the disease even after treatment, finds a new study in Cancer, the journal of the American Cancer Society.
In fact, overweight men with a BMI (body mass index) greater than 25 at the time of diagnosis are nearly twice as likely to die from advanced prostate cancer as patients with a normal BMI.
Prostate cancer is the most common cancer among Canadian men.
While treatment advances have reduced mortality rates since the early 1990s, one in eight Canadian men will develop prostate cancer during his lifetime, mostly after age 60. One in 27 will die of it.
While obesity has long been known as a risk factor for more aggressive prostate cancer, the impact of weight on the chances of survival in those who have received treatment has been less understood.
Typical advanced prostate cancer treatments include surgical removal of the prostate, external beam radiation, and hormonal therapy.
In this study, researchers at Massachusetts General Hospital in Boston studied 788 patients with locally advanced prostate cancer and followed them for over eight years.
The authors found that, compared to men with normal BMI (which is defined as anything less than 25), men with a BMI between 25 and 30 were more than 1.5 times more likely to die from their cancer.
Men with BMI greater than 30 were 1.6 times more likely to die from their disease compared to men with normal range BMI.
After five years, the prostate cancer mortality rate for men with a normal BMI was less than seven per cent, compared to about 13 per cent for men with BMI greater than 25.
Lead researcher Dr. Jason Efstathiou says his team's results support previous studies that have found similar associations between obesity and prostate cancer-related mortality.
His team says further studies are needed to see whether weight loss after prostate cancer diagnosis will change the course of the disease.
