Intensification of androgen deprivation therapy (ADT) in metastatic hormone sensitive prostate cancer (mHSPC): Patterns of use and impact on outcomes from a large academic medical center.

Abstract

e17115 Background: ADT intensification with docetaxel and/or androgen receptor pathway inhibitors (ARPIs) has survival benefit in mHSPC. While triplet (ADT+ docetaxel + ARPI) or doublet (ADT + ARPI) therapy is standard of care, studies have shown intensification may be underutilized. Here, we evaluate patterns of ADT intensification in pts with mHSPC and impact on survival outcomes at a large academic medical site. Methods: Pts who received continuous ADT at Indiana University from 1/1/17 to 3/26/24 for mHSPC were included. Demographics, disease characteristics, and treatment regimens were summarized. Pts were grouped into those who received intensification (RI) vs no intensification (NI). Comparisons between cohorts were done using chi-squared and Wilcoxon test. Progression free survival (PFS) and overall survival (OS) were analyzed with Kaplan-Meier method, and comparisons between groups done using log-rank test. Results: 339 pts were included, of which 188 (55.5%) RI. Median age at diagnosis was 67.6 yrs (range 40.8-92). 58.4% were white, 13.6% black, 0.9% Asian, and 27.1% unknown race. 30.1% of pts had high volume disease. Met sites included regional (61.9%) and distant (21.2%) lymph nodes, bone (65.5%), lungs (7.4%), liver (3.2%), brain (0.3%), and other (5.6%). Leuprolide (85.3%), relugolix (12.1%) or degarelix (2.7%) were used for ADT. Of those who RI, 80.3% received an ARPI; 62.3% received abiraterone, 14.6% darolutamide, 13.9% apalutamide, and 9.3% enzalutamide. 56 pts (29.8%) of those who RI received docetaxel- 33.9% as triplet therapy. Table 1 summarizes clinical characteristics in RI vs NI groups. In 65.6% of pts with NI, reason for NI was not given. Patient preference was the reason for NI for 17.2% of pts, physician preference for 9.3%, medical comorbidities for 7.9%, age for 3.3%, performance status for 3.3%. Median PFS was 3.6yrs (95% CI 2.7-5.9) for those who RI vs 2.5yrs (95% CI 2-3.2) for those with NI (p=0.0083). Median OS was 7.3 yrs for those who RI vs 9.3 for those with NI (p=0.75). Conclusions: While PFS was longer for those who RI, these pts also had higher volume of disease, higher PSA, and higher rates of de novo disease, likely contributing to poorer OS. Even at a large academic institution, only about half of pts received intensification. Pts not given intensification were older, and patient preference was the most commonly identified reason for not receiving intensification. Characteristics of pts who received intensification vs pts who did not. No Intensification (n=151) Received Intensification (n=188) P-value Age at diagnosis (yrs) 70.1 65.4 <0.0001 ECOG PS at diagnosis of 0-1 137 (90.7%) 181 (96.3%) 0.0502 High volume disease 34 (22.5%) 68 (36.2%) 0.0073 De novo metastatic disease 48 (31.8%) 99 (52.7%) 0.0002 Median PSA at diagnosis 13.1 20.7 0.0135 Presence of bone mets 89 (58.9%) 133 (70.7%) 0.0231