Smaller prostates also increase the risk of aggressive disease, they say.
Both findings are being presented at the annual meeting of the American Urological Association May 21-26 in San Antonio.
The obesity study examined the association between body mass index weight to height ratio and prostate cancer in 787 men undergoing biopsy due to an elevated tumor marker in the blood or an abnormal physical exam at a Veterans Affairs hospital in California between 1998 and 2002.
It indicated that obesity increases the risk of prostate cancer, particularly in young men, as well as the risk of aggressive disease in all men.
"The exact relationship between obesity and prostate cancer is still very much a point of controversy and debate in urology," says Dr. Martha K. Terris, urologist at the Veterans Affairs Medical Center in Augusta and the Medical College of Georgia.
"One consensus that seems to be evolving is that obese men have an increased risk of more aggressive, and therefore potentially more deadly, disease," she says. "The take-home message for men and for all of us really is that we should try to maintain a healthy weight for a variety of health reasons."
Obesity may literally be a deterrent to finding prostate cancer because it makes digital rectal exams, a major screening tool, more difficult, says Dr. Terris. Also, in men and women alike, fat makes estrogen-like compounds, which lowers circulating levels of prostate specific antigen, or PSA, a marker for prostate cancer. If PSA levels are lower due to hormone changes from obesity, the prostate cancer is less likely to be detected at an early stage.
Hormone changes observed with obesity also cause decreased levels of the male hormone testosterone. Since testosterone feeds prostate cancer, obesity could, in theo
Contact: Toni Baker
Medical College of Georgia