Twelve prostate biopsies detect significant cancer volumes (> 0.5 mL).

OBJECTIVES

To compare, in a retrospective study, pathological specimens of prostate cancer detected in additional areas of a 12-core biopsy with tumours detected using traditional sextant biopsy.

PATIENTS AND METHODS

The study included 27 patients who had undergone radical prostatectomy (RP) for prostate cancer. Prostatectomy specimens of cancers detected using standard sextant biopsies were compared with those detected using six additional core biopsies. The RP specimens were analysed for cancer volume, Gleason score, tumour grade (Mostofi) and pathological stage.

RESULTS

Of the 27 patients, six (29%) had cancer detected in the extra six biopsy cores which would have otherwise have been undetected using sextant biopsy. Only two insignificant cancers were detected. The mean Gleason score was 6.1 for cancer detected by the sextant or 12-core method (P = 0.907); the mean grade (Mostofi) was 2.1 and 2. 33, respectively (P = 0.29). The final tumour stage in the 21 patients undergoing sextant biopsy was pT2 in 13 and pT3 in eight, compared with six pT2 tumours in the six patients diagnosed using extra biopsies. The mean (median, range) tumour volume was 5.7 (3.5, 0.312-23.75) mL for cancers detected on sextant biopsy and 1.99 (1. 85, 0.4-3.6) mL in the six cancers detected using extra cores (P = 0. 0138).

CONCLUSION

The detection of prostate cancer was increased using extra biopsy cores. There was a significant difference in tumour volume but not in Gleason score, Mostofi grade or final pathological tumour stage between tumours diagnosed using 12 cores and those detected on sextant biopsy.