5α-Reductase inhibitors and risk of high-grade or lethal prostate cancer - Abstract

IMPORTANCE: 5α-Reductase inhibitors (5ARIs) are widely used for benign prostatic hyperplasia despite controversy regarding potential risk of high-grade prostate cancer with use.

Furthermore, the effect of 5ARIs on progression and prostate cancer death remains unclear.

OBJECTIVE: To determine the association between 5ARI use and development of high-grade or lethal prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS: Prospective observational study of 38 058 men followed up for prostate cancer diagnosis and outcomes between 1996 and 2010 in the Health Professionals Follow-up Study.

EXPOSURES: Use of 5ARIs between 1996 and 2010.

MAIN OUTCOMES AND MEASURES: Cox proportional hazards models were used to estimate risk of prostate cancer diagnosis or development of lethal disease with 5ARI use, adjusting for possible confounders including prostate specific antigen testing.

RESULTS: During 448 803 person-years of follow-up, we ascertained 3681 incident prostate cancer cases. Of these, 289 were lethal (metastatic or fatal), 456 were high grade (Gleason sum [GS] 8-10), 1238 were GS 7, and 1600 were low grade (GS 2-6). A total of 2878 (7.6%) men reported use of 5ARIs between 1996 and 2010. After adjusting for confounders, men who reported ever using 5ARIs over the study period had a reduced risk of overall prostate cancer (hazard ratio [HR], 0.77; 95% CI, 0.65-0.91). 5ARI users had a reduced risk of GS 7 (HR, 0.67; 95% CI, 0.49-0.91) and low-grade (GS 2-6) prostate cancer (HR, 0.74; 95% CI, 0.57-0.95). 5ARI use was not associated with risk of high-grade (GS 8-10) prostate cancer (HR, 0.97; 95% CI, 0.64-1.46) or lethal disease (HR, 0.99; 95% CI, 0.58-1.69). Increased duration of use was associated with significantly lower risk of overall prostate cancer (HR for 1 year of additional use, 0.95; 95% CI, 0.92-0.99), localized (HR, 0.95; 95% CI, 0.90-1.00), and low-grade disease (HR, 0.92; 95% CI, 0.85-0.99). There was no association for lethal, high-grade, or grade 7 disease.

CONCLUSIONS AND RELEVANCE: While 5ARI use was not associated with developing high-grade or lethal prostate cancer, it was associated with a reduction in low-grade, GS 7, and overall prostate cancer. Because the number of patients with high-grade or lethal prostate cancer in our cohort was limited, we cannot rule out potential risk of harm with 5ARI use.

Written by:
Preston MA, Wilson KM, Markt SC, Ge R, Morash C, Stampfer MJ, Loda M, Giovannucci E, Mucci LA, Olumi AF.   Are you the author?
Department of Urology, Massachusetts General Hospital, Boston; Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; Division of Urology, University of Ottawa, Ottawa, Ontario, Canada; Departments of Pathology and Medical Oncology, Dana-Farber Cancer Institute, Brigham and Women's and Hospital, Boston, Massachusetts; Broad Institute of Harvard and MIT, Cambridge, Massachusetts; Division of Cancer Studies, King's College London, London, En; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Nutrition, Harva.

Reference: JAMA Intern Med. 2014 Jun 2. Epub ahead of print.
doi: 10.1001/jamainternmed.2014.1600


PubMed Abstract
PMID: 24887392

UroToday.com Prostate Cancer Section