Lost opportunities: the underutilization of castrate-resistant prostate cancer treatment in real-world settings.

Background: Various treatment regimens are now available for metastatic castrate-resistant prostate cancer (CRPC). This work evaluates the real-world prescription patterns of CRPC in a large tertiary care center and the factors influencing them.

Methods: Health records of 330 patients with de novo metastatic hormone-sensitive prostate cancer (HSPC), treated and progressed to CRPC between 2016 and 2020, were reviewed from a prospective uro-oncological database. We studied their demographics, medical co-morbidities, treatment utilization patterns before and after progression to CRPC, and survival outcomes.

Results: The median age was 74 years [interquartile range (IQR), 67-80 years] at diagnosis of CRPC. At CRPC, beyond androgen deprivation therapy (ADT) monotherapy, 70.3% (n=232) of patients received at least one additional line, 21.5% (n=71) received two lines, and 5.5% (n=18) received three lines of systemic treatments. As first-line treatment, novel hormonal agents (NHAs) were the most prescribed at 57.6% (n=190). The likelihood of receiving treatment was associated with age <65 years [odds ratio (OR) 2.08, P=0.01, 95% confidence interval (CI): 1.22-3.57] and lower Charlson Comorbidity Index (CCI) score (OR: 2.62, P=0.04, 95% CI: 1.07-6.45), treatment intensification for HSPC (OR 2.45, P=0.04, 95% CI: 1.07-5.62) and primary physician being an oncologist (OR 1.59, P=0.04, 95% CI: 1.04-2.48). Patients who received additional treatment lines at CRPC had longer survival (median: 23 vs. 17 months, OR 1.72, P<0.01, 95% CI: 1.23-2.38).

Conclusions: More than one in four patients do not receive any additional treatment line beyond ADT monotherapy and have worse survival outcomes. Health status, prescribing physician, and treatment at HSPC appear to affect prescription patterns at the CRPC stage.