Obese men tend to have lower PSA (prostate-specific antigen) measurements than normal-weight men, possibly because they have more blood, which could dilute their PSA reading. A study released Thursday looked at the consequences.
'Now we know some of the real implications of this,' said Dr. Stephen Freedland, the study's lead investigator.
'These men are at a disadvantage in terms of prognosis compared to normal-weight men,' he added in a release on Friday.
Freedland and his colleagues at Duke University came to that conclusion after studying data from nearly 3,400 men.
They compared men who had their cancers detected by PSA to those who had an abnormal digital rectal exam, an older method of screening for prostate cancer.
Obese patients who had their cancer diagnosed by PSA had more than twice the risk of cancer recurring after surgery compared with normal-weight patients, the researchers found.
But for those who had abnormal digital rectal exams, the outcomes were similar regardless of weight.
An earlier study by the team also concluded that there was a higher chance of cancer being left behind after surgery in obese men.
'The aggressiveness of obese men's tumours, coupled with the fact that they may be more difficult to remove, is like a double whammy for being obese,' said Duke oncologist Dr. Jayakrishnan Jayachandran, who led the previous study.
Freedland's study appears in Thursday's online issue of BJU International.