225P - Prostate cancer treatments and outcomes in the elderly: A retrospective analysis of an Australian real-world cohort

Background

Elderly men (>/=75yo) comprise 25% of patients with prostate cancer. However, they are typically underrepresented in pivotal trials. Limited data suggest these patients receive less intensive treatment with greater toxicity, despite comparable response rates. Our retrospective study examined treatment patterns and outcomes in a real-world population with castration-resistant prostate cancer (CRPC).

Methods

Using the multi-centre electronic CRPC Australian Database (ePAD), we extracted clinicopathologic, treatment and outcome data. Descriptive statistics were used to report data in patients aged >/=75yo and <75yo. Comparisons between these groups were analysed using T-tests and Fisher’s exact tests. Time-to-event analyses were performed using the Kaplan-Meier method.

Results

We identified 753 men with CRPC, with 327 (43%) aged >/=75yo. Elderly patients had higher rates of ischemic heart disease (33% vs 16% in younger patients, p=0.004) and stroke (11% vs 5%, p=0.007). They were more likely to receive only one line of systemic therapy (67% vs 40%, p<0.001), and androgen receptor signalling inhibitors (ARSIs) were most commonly prescribed as initial therapy (78% vs 48%, p<0.001). Enrolment in clinical trials was less frequent (5% vs 15%, p<0.001). There was no statistical difference in treatment duration or PSA50 response rates with ARSIs or docetaxel (Table). Overall, serious adverse events (SAEs) leading to hospitalisation, dose delays or modifications occurred in more elderly men (24% vs 16%, p=0.003), with a trend towards greater SAEs in those receiving docetaxel or ARSIs. Elderly patients were more likely to stop docetaxel due to toxicity (39% vs 21%, p=0.02). Table: 225P

First-line therapy for CRPC

Conclusions

In our real-world cohort, elderly men had greater comorbidities and received fewer lines of systemic therapy. Although there was no difference in treatment response or duration, elderly patients experienced higher SAE rates. Prospective studies are required to further evaluate long-term outcomes in these patients.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Astellas, AstraZeneca, Janssen, Amgen.

Disclosure

E. Kwan: Honoraria (self): Janssen; Honoraria (self), Travel/Accommodation/Expenses: Ipsen; Research grant/Funding (institution), Travel/Accommodation/Expenses: Astellas; Research grant/Funding (institution), Travel/Accommodation/Expenses: Pfizer; Research grant/Funding (institution): AstraZeneca; Research grant/Funding (institution): Bristol-Myers Squibb; Research grant/Funding (institution): Merck Serono. F.X. Parnis: Leadership role, Administrative Board: Janssen; Leadership role, Administrative Board: Astellas; Leadership role, Administrative Board: Bayer. All other authors have declared no conflicts of interest.