Prior therapy and volume of disease are prognostic for metastatic hormone sensitive prostate cancer (mHSPC) in a hospital-based database.

Abstract

221 Background: Recent reports have shown that patients (pts) with low volume (LV) mHSPC and those who relapse after prior local therapy (PLT) have median overall survival (OS) longer than 5 years with androgen deprivation therapy (ADT) alone. Using data from our prospectively collected hospital-based database, we aimed to detail the outcomes of pts with mHSPC by combining PLT or de novo (DN) and LV or high volume (HV) of disease. Methods: A cohort of mHSPCpts treated with ADT between 1990 and 2013 was identified in the Dana-Farber Cancer Institute IRB approved database and categorized as DN or PLT and HV or LV, at time of ADT start. HV was defined as visceral metastases and/or ≥ 4 bone metastases (BM) with at least 1 BM beyond the pelvis and axis. The analysis endpoints included OS, defined as time from ADT start to death from all causes. Kaplan-Meier method estimated the time to events distribution with median (95% CI). Cox proportional hazards model evaluated patient and disease volume groups on disease outcomes and provided estimates of hazard ratio (95% CI) for the comparison by groups. Results: Of the 354 pts included and classified as LV or HV, 202 (57%) had PLT, while 152 (43%) presented with DN metastases. The distributions of the 4 groups are 38% (PLT/LV), 19% (PLT/HV), 14% (DN/LV) and 29% (DN/HV). Compared to pts in PLT/LV group, those in the other 3 cohorts had a significantly higher risk of death. In particular, a statistically significant gradient in OS was noted (Trend test P < 0.001) within the groups in favor of PLT, primarily, and LV, secondarily. Conclusions: Consistent with the results seen in clinical trials, our hospital database informs us that disease volume and history of PLT define 4 distinct subgroups with different outcomes. This classification can be routinely used for counseling pts and future clinical trial design including oligometastatic disease. [Table: see text]