April 24, 2013
For Obese Men, Even Benign Biopsies Have High Risk Of Becoming Prostate Cancer
redOrbit Staff & Wire Reports - Your Universe Online
Researchers from the Columbia University Mailman School of Public Health have discovered that benign precancerous lesions detected in prostate biopsies are more likely to develop into prostate cancer for obese men compared to their normal-weight counterparts.Writing in the online edition of the journal Cancer Epidemiology, Biomarkers & Prevention, study author and associate professor of epidemiology Andrew Rundle and colleagues investigated the link between obesity and future prostate cancer incidence with a cohort of 6,692 men at the Henry Ford Health System.
The study participants were followed for 14 years after a biopsy or transurethral resection of the prostate with benign findings. They conducted a case-controlled study of 494 of those patients, as well as 494 matched control subjects, and discovered “precancerous abnormalities” in 11 percent of the participants´ benign specimens. Rundle said that those abnormalities were associated with obesity at the time of the biopsy.
They accounted for family history of the disease, prostate-specific antigen (PSA) levels during the initial procedure, and the number of PSA tests and digital rectal exams during follow-up. They discovered that obesity at the time of the biopsy was associated with a 57 percent increase in the likelihood of being diagnosed with prostate cancer during follow-up exams.
“Our study is focused on a large group of men who have had a prostate biopsy that is benign but are still at a very high risk for prostate cancer,” Rundle said in a statement. “Studies conducted in the past have attempted to determine if there are subpopulations of men diagnosed with benign conditions that may be at a greater risk for developing prostate cancer. This is one of the first studies to assess the association between obesity and precancerous abnormalities.”
He added that the association was only detected for tumors which occurred earlier in the follow-up period.
“We don't absolutely know what the true biology is,” Rundle said. “In some ways, this reflects the association between the body size and larger prostate size, which is thought to reduce the sensitivity of the needle biopsy. It is possible that the tumors missed by initial biopsy grew and were detected in a follow-up biopsy.”
Rundle explained that the link between body weight and prostate cancer was greater than that observed in previous studies, and he said that the differences may be because the current study focused only on men who were at high risk for prostate cancer. He added that the researchers need additional “guidance” to determine whether or not a full follow-up study is required — and, if so, when that should take place.
Regardless, Rundle said, the research demonstrates that “obesity should be considered a factor for more intensive follow-up after a benign prostate biopsy.”