Modeling and analysis of Gleason score 8-10 prostate cancers in the REDUCE study.

Authors

• Gerald L Andriole
• David G Bostwick
• Leonard G Gomella
• Michael Marberger
• Francesco Montorsi
• Teuvo L Tammela
• Donald J Tindall
• Ivy L Fowler
• Harmony P Garges
• Timothy H Wilson
• Ramiro Castro

Publication/Presentation Date

8-1-2014

Abstract

OBJECTIVE: To explore explanations for the numerical imbalance of biopsy-detected Gleason 8-10 prostate cancers (PCa) diagnosed in years 3-4 in the dutasteride and placebo groups of the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study.

METHODS: REDUCE was a 4-year, randomized, double-blind, placebo-controlled trial of dutasteride (0.5 mg/d) vs placebo for PCa risk reduction. We modeled the incidence of Gleason 8-10 cancer and used logistic regression analysis to evaluate the effects of baseline predictors of PCa, as well as post-baseline prostate volume at the time of biopsy, on PCa diagnosis. We compared needle biopsy Gleason scores with corresponding surgery Gleason scores. All statistical tests conducted were 2-sided.

RESULTS: Had there been a scheduled biopsy occurring only at year 4, we estimated a similar incidence of Gleason 8-10 PCa in the dutasteride (n = 45) and placebo (n = 46) groups. Two biopsy Gleason 7 cancers in the placebo group (n = 150) were upgraded to Gleason 8-10 cancer on prostatectomy, and no patients in the dutasteride group (n = 111) were upgraded. Logistic regression analysis demonstrated the effect of prostate volume on Gleason 8-10 cancer diagnosis.

CONCLUSION: Although modeling of REDUCE data showed a similar incidence of Gleason 8-10 cancer in the dutasteride and placebo groups at year 4, an association between dutasteride and Gleason 8-10 cancer cannot be definitely excluded. It is likely that several biases, notably study design and prostate size at the time of biopsy, contributed to the numerical imbalance in Gleason 8-10 cancers observed between the treatment groups in years 3-4.

Volume

84

Issue

2

First Page

393

Last Page

399

ISSN

1527-9995

Published In/Presented At

Andriole, G. L., Bostwick, D. G., Gomella, L. G., Marberger, M., Montorsi, F., Tammela, T. L., Tindall, D. J., Fowler, I. L., Garges, H. P., Wilson, T. H., & Castro, R. (2014). Modeling and analysis of Gleason score 8-10 prostate cancers in the REDUCE study. Urology, 84(2), 393–399. https://doi.org/10.1016/j.urology.2014.04.016

Disciplines

Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods

PubMedID

24916669

Department(s)

Administration and Leadership

Document Type

Article