Six core versus twelve core prostate biopsy: A retrospective study comparing accuracy, oncological outcomes and safety - Beyond the Abstract

In the Republic of Ireland the National Cancer Control Programme (NCCP) established guidelines to standardise the prostate biopsy technique in 2009. A notable recommendation was that 12 core prostate biopsies should be taken during the biopsy protocol instead of the traditional sextant biopsy. Perceived limitations with sextant biopsies were false negative rates that ranged from 28-42% (1).

The potential advantages associated with a 12 core prostate biopsy are improved accuracy for diagnosing prostate cancer (PCa) in male patients. Studies by Durkan et al. and Ceylan et al. demonstrated that the cancer detection rate increased by approximately 20% when sextant core biopsies were compared with 12 core biopsies (2, 3).

Currently, 12 core TRUS biopsies are performed in all prostate cancer centres as per National Cancer Control Policy (NCCP) guidelines (4). However, it has been hypothesised that the increased number of core biopsies may be associated with an increased risk of diagnosing clinically insignificant prostate cancer and/or developing post biopsy complications such as urosepsis (5). This was the first Irish study to compare the histopathology of six and twelve core biopsies in terms of detection rates for prostate cancer. We also investigated whether 12 core prostate biopsies are associated with a higher incidence of insignificant prostate cancer and complications requiring inpatient admission.

A total 286 patients were included in this retrospective case-controlled study; 143 underwent sextant core biopsy and 143 underwent 12-core biopsy. The most notable findings of the study were that 12 core biopsies were associated with higher PCa cancer detection rates, greater accuracy for Gleason grading and no difference in terms of detecting clinically insignificant PCa compared to sextant biopsies. In addition, 12 core biopsies were not associated with higher rates of post biopsy complications.

References:
1. Crawford ED., Hirano D, Werahera PN, et al (1998) Computer modeling of prostate biopsy: tumor size and location - not clinical significance - determine cancer detection. J Urol, 159: 1260.
2. Durkan GC, Sheikh N, Johnson P, et al. (2002) Improving prostate cancer detection with an extended-core transrectal ultrasonography-guided prostate biopsy protocol. BJU Int. 89(1):33-9.
3. Ceylan C, Doluoglu OG, Aglamis E, et al (2014) Comparison of 8, 10, 12, 16, 20 cores prostate biopsies in the determination of prostate cancer and the importance of prostate volume. Can Urol Assoc J. (1-2):E81-5.
4. Weblink: http://www.cancer.ie/cancer-information/prostate-cancer/symptoms-and-diagnosis#sthash.lrjO5zGN.dpbs (Last accessed January 2015)
5. Rodrigues LV, Terris M.K (1998). Risks and Complications of Transrectal Ultrasound Guided Prostate Needle Biopsy: A Prospective Study and Review of the Literature. J Urol 160(6): 2115–2120

Written by:
W Mohammed, NF Davis, S Elamin, P Ahern, CM Brady, P Sweeney
Department of Urology, Mercy University Hospital, Cork City, Co Cork, Ireland.

AbstractSix core versus twelve core prostate biopsy: A retrospective study comparing accuracy, oncological outcomes and safety