Effect of Prostate Size on Cancer Detection Rate of Traditional Sextant Prostate Biopsy / 대한비뇨기과학회지

ABSTRACT

PURPOSE: We aimed to evaluate whether cancer detection rates could vary with prostate size using a systematic sextant biopsy. MATERIALS AND METHODS: We performed a systematic sextant biopsy in 225 consecutive men from January 1997 to August 2002. Indications for biopsy included an elevated prostate specific antigen(PSA) level(more than 4.0ng/ml), or the hypoechoic lesion on TRUS. Prostate volume was calculated using the following fomula volume=0.52 x length x width x height. We examined biopsy yield according to gland-volume intervals of 10cc. RESULTS: Adenocarcinoma was detected in 68 out of 225 patients(30.22%). The mean volume of prostate in all patients was 51.5cc. The highest biopsy rate(65.7%) was recorded among men with prostates between 20 to 29.9cc. The lowest biopsy rate (17.2%) was recorded among men with prostates larger than 80cc. Decreasing yield of sextant biopsy was strongly associated with increasing gland volume(p or =30cc)(62.63% and 22.09%, respectively, p or =30cc) prostate groups. CONCLUSION: Our cancer detection rate using a systematic sextant biopsy was higher in men with prostates less than 30cc. Our results suggest that significant sampling error may occur in men with large glands, and more biopsies may be needed under these circumstances.