First author Dr. Andrew Rundle of the Columbia University Mailman School of Public Health and colleagues investigated the association between obesity and future prostate cancer incidence within a cohort of 6,692 men at the Henry Ford Health System who were tracked for 14 years after a biopsy or transurethral resection of the prostate with benign findings.
The investigation was part of a larger study for prostate cancer.
The researchers conducted a case-control study among 494 of these patients and 494 matched controls; they found precancerous abnormalities in 11 percent of the patients' benign specimens. These abnormalities were significantly associated with obesity at the time of the procedure, Rundle said.
After accounting for several variables, including family history of prostate cancer and prostate-specific antigen levels, the researchers found that obesity at the time of the initial procedure was associated with a 57 percent increased incidence of prostate cancer during follow-up.
Rundle noted this association was only apparent for tumors occurring earlier in the follow-up period.
"We don't absolutely know what the true biology is," Rundle said in a statement. "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. Obesity should be considered a factor for more intensive follow-up after a benign prostate biopsy."
The findings were published online in Cancer Epidemiology: Biomarkers & Prevention.