Treatment Landscape for Older Men With Metastatic Hormone-Sensitive Prostate Cancer in the United States.

[OBJECTIVE] This study evaluated treatment patterns and factors associated with androgen deprivation therapy (ADT) intensification with androgen receptor pathway inhibitors (ARPI) and/or docetaxel among older men with mHSPC in the United States.

[METHODS] The study utilized a retrospective cohort of 6850 older men (age ≥ 67 years) diagnosed with mHSPC between July 2016 and December 2019 from the Surveillance, Epidemiology, and End Results Medicare-linked database. Men must maintain continuous enrollment in Medicare fee-for-service Parts A/B/D for ≥ 12 months before mHSPC diagnosis and ≥ 6 months after diagnosis. Initial treatment was classified as ADT alone, ADT + ARPI, or ADT + docetaxel. Factors associated with initial treatment were examined using multivariable multinomial logistic regression.

[RESULTS] The study cohort (mean age = 76.6 years, SD = 7.0) was mostly non-Hispanic white (77.7%), followed by non-Hispanic Black (8.4%) and Hispanic (6.5%). 30.4% received no systemic drug therapy within 6 months of mHSPC diagnosis, 47.1% received ADT alone, 14.8% received ADT + ARPI, and 5.9% received ADT + docetaxel. Among men treated with ADT, there was an increase in ADT + ARPI treatment from 19.0% to 30.0% and a concomitant decline in ADT monotherapy from 72.1% to 62.6% between 2017 and 2019, while ADT + docetaxel treatment marginally decreased from 8.8% to 7.3%. In multinomial logistic regression, men with de novo mHSPC were more likely to receive ADT + docetaxel (aOR = 2.73, 95% CI = [2.07, 3.60]) or ADT + ARPI (aOR = 1.56, 95% CI = [1.32, 1.84]); whereas men with higher frailty index were less likely to receive ADT + docetaxel (aOR = 0.93, 95% CI = [0.91, 0.95]) or ADT + ARPI (aOR = 0.97, 95% CI = [0.96, 0.98]). Specifically, ADT + ARPI was less likely to be utilized among the lower socio-economic status groups.

[CONCLUSIONS] Three in 10 older men with mHSPC received no systemic treatment. Although there was a gradual uptake of ARPIs, monotherapy with ADT was still highly prevalent, suggesting the integration of intensified treatment is still suboptimal. Targeted interventions are necessary to enhance guideline adherence among older and frail men with mHSPC.