Abstract 711P
Background
ICI plus chemotherapy (ICT) is the standard treatment for extensive-stage small cell lung cancer (ES-SCLC). However, its efficacy and safety in elderly individuals have not been investigated. Previously, we reported oligometastasis (OM) as a prognostic factor in ES-SCLC. In this study, we investigated the frequency of OM and its prognostic effect on older patients.
Methods
Data of patients diagnosed with ES-SCLC and treated with 1st-line ICT were retrospectively reviewed between September 2019 and June 2022. Patient backgrounds and outcomes were compared between the elderly (≥ 75 years) and non-elderly (< 75 years) cohorts. Synchronous OM (SOM) and oligoprogression (OP) were defined as a maximum of five worsened or newly appearing lesions in up to two organs at the start of 1st-line treatment and disease progression after 1st-line treatment, respectively.
Results
In total, 228 patients (42 elderly individuals) were included. Baseline patient characteristics did not significantly differ between the elderly and non-elderly groups: median age (range), 77 (75–86) and 69 (47–74) years; male, 71% and 73%; ECOG PS 0-1, 85% and 88%, respectively. SOM frequency was 21% (p = 1.0) in both groups. Among patients who received 2nd-line treatment, the frequencies of OP in the elderly and non-elderly groups were 45% and 51% (p = 0.68), respectively. In the elderly group, median OS of 1st-line treatment was 11.5 and 12.6 months for SOM and non-SOM (p = 0.74); median OS of 2nd-line treatment was 16.0 and 13.2 months for OP and non-OP (p = 0.62), respectively; both were not significantly different in the elderly group. In the non-elderly group, median OS was 20.6 and 15.8 months (p = 0.02) for SOM and non-SOM and 13.1 and 7.2 (p < 0.01) for OP and non-OP, respectively; both were significantly better in the OM patients.
Conclusions
The frequencies of SOM and OP were not significantly different between elderly and non-elderly patients. However, elderly patients with SOM and OP showed no significant prognostic improvement compared with those without SOM or OP. When deciding to add local treatment based on the number of lesions, it is necessary to consider that elderly patients with OM may not benefit as much.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
H. Asahina.
Funding
Has not received any funding.
Disclosure
H. Asahina: Financial Interests, Personal, Invited Speaker: Chugai Pharmaceutical, AstraZeneca, MSD, Ono Pharmaceutical, Kyowahakko Kirin, Eli Lilly, Merck; Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Research Grant: AstraZeneca. H. Tanaka: Financial Interests, Personal, Invited Speaker: AstraZeneca, Chugai. H. Kikuchi, Y. Hosomi: Financial Interests, Personal, Invited Speaker: AstraZeneca. H. Yokouchi: Financial Interests, Personal, Invited Speaker: AstraZeneca; Financial Interests, Institutional, Local PI: AstraZeneca, Bristol Myers Squibb, Sanofi, Takeda Pharmaceutical Company Limited, Chugai Pharmaceutical Company Limited, Daiichi Sankyo Company Limited. S. Oizumi: Financial Interests, Personal, Invited Speaker: AstraZeneca, Chugai; Financial Interests, Personal, Research Grant: AstraZeneca, Chugai. All other authors have declared no conflicts of interest.