Amrubicin monotherapy for refractory, relapsed, small cell lung cancer in elderly patients.

Abstract

Background: Amrubicin monotherapy has been used in Japan for patients with refractory, relapsed, small cell lung cancer (SCLC). However, the clinical guidelines do not specify a recommended initial dose for elderly patients. This retrospective study aimed to explore the appropriate initial dose of amrubicin for elderly patients with refractory, relapsed SCLC.

Methods: This study included elderly patients (aged ≥70 years) with refractory, relapsed SCLC who received amrubicin monotherapy at Nagoya City University Hospital between April 2009 and March 2023. Patients were divided into two groups based on the initial dose: the low-dose group (<40 mg/m2) and the high-dose group (≥40 mg/m2).

Results: Forty-seven patients were included, thirty-eight in the low-dose group and nine in the high-dose group. Median progression-free survival was significantly longer in the low-dose group than in the high-dose group (3.64 vs. 1.5 months, P = 0.04), whereas overall survival was not significantly different (10.18 vs. 8.18 months, P = 0.58). Febrile neutropenia occurred in seven patients. Treatment discontinuation due to adverse events was more frequent in the high-dose group (44.4%) than in the low-dose group (13.5%). Non-infectious adverse events such as interstitial pneumonia, arrhythmia, and myocardial infarction were observed in five patients who discontinued treatment.

Conclusions: Both hematological and non-infectious adverse events may have contributed to shorter progression-free survival in the high-dose group. Low-dose administration, granulocyte colony-stimulating factor support, and close monitoring for non-infectious toxicities may be important in elderly patients.