Clinical utility of the percentage of positive prostate biopsies in predicting prostate cancer-specific and overall survival after radiotherapy for patients with localized prostate cancer

D’Amico, Anthony V; Keshaviah, Aparna; Manola, Judith; Cote, Kerri; Loffredo, Marian; Iskrzytzky, Olga; Renshaw, Andrew A

« Previous Next »International Journal of Radiation Oncology * Biology * Physics
Volume 53, Issue 3 , Pages 581-587, 1 July 2002

Clinical utility of the percentage of positive prostate biopsies in predicting prostate cancer-specific and overall survival after radiotherapy for patients with localized prostate cancer

Anthony V D’Amico, M.D., Ph.D.
- Reprint requests to: Anthony V. D’Amico, M.D., Ph.D., Department of Radiation Oncology, Brigham and Women’s Hospital, 75 Francis St., L-2 Level, Boston, MA 02215 USA. Tel: (617)-732-7936; Fax: (617)-732-7347
- Department of Radiation Oncology, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, MA, USA
Aparna Keshaviah, M.S.
- Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA
Judith Manola, M.S.
- Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA
Kerri Cote, M.S.
- Department of Radiation Oncology, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, MA, USA
Marian Loffredo (R.N., O.C.N.)
- Department of Radiation Oncology, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, MA, USA
Olga Iskrzytzky, B.S.
- Department of Radiation Oncology, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, MA, USA
Andrew A Renshaw, M.D.
- Department of Pathology, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Boston, MA, USA

Received 16 November 2001; received in revised form 25 January 2002; accepted 6 February 2002.

Abstract

To determine whether the percentage of positive prostate biopsies provides clinically relevant information to a previously established risk stratification system with respect to the end points of prostate cancer-specific survival (PCSS) and overall survival after radiotherapy for patients with clinically localized prostate cancer.

A Cox regression multivariable analysis was used to evaluate the ability of the percentage of positive prostate biopsies to predict PCSS and overall survival for 381 men who underwent radiotherapy for localized prostate cancer during the prostate-specific antigen era.

At a median follow-up of 4.3 years (range 0.8–13.3), the presence of ≤50% positive biopsies vs. >50% positive biopsies provided a clinically relevant stratification of the 7-year estimates of PCSS (100% vs. 57%, p = 0.004) in intermediate-risk patients. Moreover, all patients could be stratified into a minimal or high-risk cohort on the basis of the 10-year estimates of PCSS (100% vs. 55%, p <0.0001) and overall survival (87% vs. 40%, p = 0.02) by incorporating the percentage of positive prostate biopsy information into a previously established risk stratification system.

The clinically relevant stratification of PCSS using the percentage of positive prostate biopsies in intermediate-risk patients confirms previous findings based on prostate-specific antigen outcome. These data provide evidence to support the ability to stratify newly diagnosed patients with clinically localized disease into a minimal-risk (low-risk + low biopsy volume [≤50%] intermediate-risk) or high-risk (high biopsy volume [>50%] intermediate-risk + high-risk) cohort for prostate cancer-specific death after conventional dose radiotherapy. Additional follow-up and independent validation are needed to confirm these findings.