Transperineal biopsy prostate cancer detection in first biopsy and repeat biopsy after negative transrectal ultrasound-guided biopsy: the Victorian Transperineal Biopsy Collaboration experience

Abstract

Objectives: To present the Victorian Transperineal Biopsy Collaboration (VTBC) experience in patients with no prior prostate cancer diagnosis, assessing the cancer detection rate, pathological outcomes and anatomical distribution of cancer within the prostate.

Patients and methods: VTBC was established through partnership between urologists performing transperineal biopsies of the prostate (TPB) at three institutions in Melbourne. Consecutive patients who had TPB, as first biopsy or repeat biopsy after previous negative transrectal ultrasound-guided (TRUS) biopsy, between September 2009 and September 2013 in the VTBC database were included. Data for each patient were collected prospectively (except for TPB before 2011 in one institution), based on the minimum dataset published by the Ginsburg Study Group. Univariate and multivariate analyses were used to identify factors predictive of cancer detection on TPB.

Results: In all, 160 patients were included in the study, of whom 57 had TPB as first biopsy and 103 had TPB as repeat biopsy after previous negative TRUS biopsies. The median patient age at TPB was 63 years, with the repeat-biopsy patients having a higher median serum PSA level (5.8 ng/mL for first biopsy and 9.6 ng/mL for repeat biopsy) and larger prostate volumes (40 mL for first biopsy, and 51 mL for repeat biopsy). Prostate cancer was detected in 53% of first-biopsy patients and 36% of repeat-biopsy patients, of which 87% and 81%, respectively, were clinically significant cancers, defined as a Gleason score of ≥7, or more than three positive cores of Gleason 6. Of the cancers detected in repeat biopsies, 75% involved the anterior region (based on the Ginsburg Study Group's recommended biopsy map), while 25% were confined exclusively within the anterior region; a lower proportion of only 5% of cancers detected in first biopsies were confined exclusively within the anterior region. Age, serum PSA level and prostate volume were predictive of cancer detection in repeat biopsies, while only age was predictive in first biopsies.

Conclusions: TPB is an alternative approach to TRUS biopsy of the prostate, offering a high rate of detection of clinically significant prostate cancer. It provides excellent sampling of the anterior region of the prostate, which is often under-sampled using the TRUS approach, and should be considered as an option for all men in whom a prostate biopsy is indicated.

Keywords: TRUS; prostate biopsy; prostate cancer; transperineal.