The part of the prostate that is biopsied may matter more than the number of biopsy samples taken for accurately diagnosing prostate cancer.
It is difficult to know whether prostate biopsies are correctly identifying prostate cancer because men with prostate biopsies do not usually undergo surgery to have their prostates removed.
To determine the accuracy of prostate biopsies, Gabriel Haas, M.D., of the State University of New York Upstate Medical Center in Syracuse and colleagues performed biopsies on prostates from 164 deceased men who had no history of prostate cancer. Biopsies were taken from various areas of the prostate in an attempt to mirror the way biopsies are performed on live patients.
Almost 30% of the prostates had cancer cells, and 43% of those were clinically significant cancers as defined by tissue characteristics. Cancer detection depended more on the part of the prostate that was biopsied than on the number of samples that were taken.
“This information … can assist the clinician to design the appropriate biopsy regimen to detect clinically significant cancers that pose biologic risk and avoid the overdiagnosis of clinically insignificant cancers that would be unlikely to have an adverse effect on the patient,” the authors write.