Clinical Associations of Luminal and Basal Subtyping in Prostate Cancer
Posted: Friday, July 20, 2018
Luminal B prostate cancers carry a worse clinical prognosis than luminal A and basal-like tumors, but they respond better to postoperative androgen-deprivation therapy (ADT), according to a study by Shuang Zhao, MD, of the University of Michigan, Ann Arbor, and colleagues. They utilized the PAM50 gene-expression classifier to subtype 3,782 radical prostatectomy samples to determine associations with clinical outcomes and response to treatment. Their research was published in JAMA Oncology.
“These findings contribute novel insight into prostate cancer biology, providing a potential clinical tool to personalize ADT treatment for prostate cancer by predicting which men may benefit from ADT after surgery,” stated the investigators.
The study included both retrospectively (n = 1,567) and prospectively (n = 2,215) collected prostate cancer samples classified as three subtypes: luminal A (34.3% and 33.3%), luminal B (28.5% and 32.6%), or basal-like (37.1% and 34.1%). Luminal B prostate cancer had the poorest 10-year rates versus basal and luminal A subtypes for biochemical recurrence–free survival (29% vs. 39% vs. 41%), prostate cancer–specific survival (78% vs 86% vs 89%), and overall survival (69% vs. 80% vs. 82%).
Both luminal-like subtypes were associated with increased androgen receptor expression and signaling. However, a subset analysis of 315 patients matched by clinicopathologic variables revealed that only luminal B prostate cancers were significantly associated with postoperative response to ADT (P = .006).