Obese patients with prostate cancer have a much higher risk of the cancer growing and spreading, even with hormone therapy, compared to other prostate cancer patients, researchers from Duke University Medical Center explained at the American Urological Association annual Meeting yesterday.

The presenters informed that over the last ten years the prevalence of obesity and prostate cancer in Europe and the USA has been steadily increasing. Prostate cancer today is the second biggest cancer killer of men.

Out of every six American males, one will be diagnosed with prostate cancer at some time during his life, says the American Cancer Society. Over 33% of US males are obese.

Christopher J. Keto, M.D. and team set out to find out what obesity’s role might be in prostate cancer. They gathered data on 287 patients who had prostate cancer and had a radical prostatectomy (prostate surgically removed) at five different Department of Veteran Affairs hospitals between 1998 and 2009.

All their cancers had come back, so they were on ADT (androgen deprivation therapy). Their testosterone production was suppressed. Testosterone encourages prostate tumor growth.

The researchers found that obese men, in comparison to men of normal body weight:

  • Were three times as likely to have cancer progression.
  • Were three times as like to have their cancer spread to the bone
  • Were five times as likely to have metastasis

Keto and team say further studies are required to find out exactly what it is that gives obese men such worse outlooks than men of normal weight, even when treatments are the same. Perhaps the ADT dosage needs to be reviewed.

Keto said:
“We think perhaps obese men may require additional ADT. The dose is the same regardless of weight, while most drugs are dosed according to weight.”

Stephen J. Freedland, M.D., senior study author, said:

“By being thematic in our research we can really get to the bottom of something. The study supports a growing body of literature showing that obese men with prostate cancer do worse. Our next step is to figure out why.”

Also, knowing that obese men generally have worse outcomes might lead to better interventions, Freedland added.

The same researchers are currently involved in a study to find out what impact diet and exercise might have on obese patients’ prostate cancer treatment, including hormone therapy.

Freedland said:

“If obesity is bad for prostate cancer, we may have to be more aggressive in our treatment. Ultimately, we aim to learn why, which in turn can lead us to better treatments for these men.”

Source: Duke University Medical Center, Durham, N.C.

Written by Christian Nordqvist