Impact of new agents (NAs) on post-docetaxel (DOC) survival of octogenarians with metastatic castration resistant prostate cancer (mCRPC) patients (pts): Results of an Italian multicenter retrospective study (DELPHI study).

Abstract

e16017 Background: After DOC became the reference first line treatment for mCRPC pts, cabazitaxel (CABA), abiraterone acetate (AA), and enzalutamide (ENZ) significantly prolonged overall survival (OS) after DOC. Since a quote of pts develops mCRPC at very old age, often after 80 years, it could be questionable if the administration of these expensive NAs is justifiable in this population. We retrospectively evaluated the impact of post-DOC treatments on OS of octogenarians mCRPC pts treated with first-line DOC in 30 Italian hospitals. Methods: In this multicentric retrospective study, after Ethical Committee approval, we have reviewed the clinical records of all octogenarians mCRPC pts from participating institutions, treated with DOC in clinical practice, recording the pre and post-DOC clinical history, the DOC treatment details and outcomes. Results: We collected a consecutive series of 121 octogenarians pts treated between May 2003 and November 2013. The median age was 82 yrs (range 80-90). All pts had received 3-week or weekly DOC (44% and 56%, respectively) with a PSA reduction > 50% and an objective response achieved in 55% and 15% of the pts, respectively. The median PFS and OS were 7 mos and 20 mos, respectively. After DOC, 57 pts (47%) did not receive further systemic treatment, 21 (17%) received at least one old therapy (DOC rechallenge, mitoxantrone or other chemotherapies), and 43 (36%) received at least one NA (36 AA, 7 CABA, 9 ENZ). We compared these groups in terms of OS and post-DOC progression OS 3-month landmark analysis to avoid the bias due to early deaths after progression (see table). Conclusions: Although our population is highly selected and our data was obtained from a retrospective analysis, our results suggests that NAs are able to significantly prolong OS also in octogenarians mCRPC pts. This is valuable in the light of the debate concerning the appropriate use of NAs in the daily clinical practice. Post-DOC treatment Median OS Median post-DOC progression OS* No further therapy (57 pts) 14 9 Old therapies (21 pts) 20 14 NAs (43 pts) 33 26 P value < 0.0001 < 0.0001 *3-month landmark analysis