Cancer may go undetected without regional prostate biopsy cores
Prostate biopsies in men with a PSA level of 4.01-10.0 ng/mL and normal findings on digital rectal examination (DRE) should include lateral cores in addition to the sextant biopsy, according to investigators.
A study led by Hiromi Uno, MD, of Hirano General Hospital in Gifu, Japan, studied 313 men who underwent transrectal ultrasound-guided 14-core prostate biopsy because of PSA levels greater than 4.0 ng/mL and/or abnormalities found on DRE. In addition to standard six biopsy cores, six lateral cores and two transition zone cores were obtained.
Of the 313 men, 127 (40.6%) were found to have prostate cancer, the researchers reported in Urology (2008;71:23-27). If only the sextant biopsy had been performed, 28 cancers (22%) would not have been detected, according to the researchers. Of these 28, 24 were found in the far lateral region only, three were found in the far lateral region and transition zone, and one was found in the transition zone only.
Among the 211 patients with normal DRE findings, the cancer detection rate with 14-core biopsy was 29.4% versus 19.9% with the six-core biopsy. Of the 211 patients, 141 had a PSA level of 4.01-10.0 ng/mL. In this group, the cancer detection rate was 25.5% with the 14-core biopsy versus 15.6% with the six-core biopsy.
The mean PSA level was 47.2 ng/mL for men with cancer compared with 7.7 ng/mL for those without cancer. Fifty-one percent of those with cancer had abnormal DREs compared with about 20% of those without cancer. Additionally, men with cancer were significantly older than those without cancer (71.8 vs. 68.7 years).
Positive biopsies were 17.2%, 30.4%, 50.9%, and 82.6% in men with PSA levels of 4.0 or less, 4.01-10.0, 10.01-20.0, and greater than 20.0 ng/mL, respectively. The incidences of localized disease (T2 or less) for these PSA levels were 100%, 98.2%, 86.2%, and 39.5%, respectively.