LAUSR

Abstract Background Polypharmacy (PP) is a common problem in elderly patient population. However, the prevalence and impact of PP on treatment-related morbidities in elderly patients with advanced cancer have not been well investigated. Methods We retrospectively analyzed data from 157 elderly (aged ≥65 years) patients treated with immune checkpoint inhibitor (ICI) for advanced or recurrent non-small cell lung cancer (NSCLC). Statistical analysis was performed using the Kaplan–Meier method and Cox regression adjusted for risk factors. Results The prevalence of PP, defined as ≥ 5 medications, was 40.1% (63/157). The prevalence of potentially inappropriate medication (PIM), according to the screening tool of older people's prescription (STOPP) criteria version 2, was 38.2% (60/157). The median progression-free survival (PFS) times in patients with and without PP were 3.7 [95% confidence interval (CI), 1.8–5.4] and 5.5 (95% CI, 3.4–9.0) months, respectively (P = 0.0017). The median overall survival (OS) times in patients with and without PP were 9.5 (95% CI, 6.0–14) and 28.1 (95% CI, 13.3–not reached) months, respectively (P  Conclusions PP is an independent prognostic factor in elderly patients with advanced or recurrent NSCLC treated with ICI. Although PP may not affect the efficacy or toxicity of ICI, it is useful as a simple surrogate indicator of comorbidities or as a predictive marker of negative events during ICI treatment. Editorial acknowledgement The authors thank Enago for the English language review. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure Y. Hosomi: Speaker Bureau / Expert testimony: AstraZeneca; Speaker Bureau / Expert testimony: Chugai Pharmaceutical; Speaker Bureau / Expert testimony: Eli Lilly Japan; Speaker Bureau / Expert testimony: Ono Pharmaceutical; Speaker Bureau / Expert testimony: Taiho Pharmaceutical. All other authors have declared no conflicts of interest.