Similar Survival in ES-SCLC with Cis/Carbo Plus Etoposide

Therapy with either cisplatin and etoposide or carboplatin and etoposide achieved similar survival results, though average treatment effect was more favorable with cisplatin and etoposide in patients who were fit, among those with frontline extensive-stage small cell lung cancer (SCLC), according to results from a modern, real-world analysis shared at the IASLC 2025 World Conference on Lung Cancer (WCLC).

The median overall survival (OS) was 8.8 months (95% CI, 8.2-9.5) with cisplatin and etoposide compared with 7.8 months (95% CI, 7.4-8.3) with carboplatin and etoposide; the median progression-free survival (PFS) were 5.8 months (95% CI, 5.5-6.2) and 5.1 months (95% CI, 4.9-5.5), respectively. Treatment was discontinued due to toxicity in 18% of patients in both groups, and consolidative thoracic radiotherapy was received by 21% of the cisplatin and etoposide group and 19% of the carboplatin and etoposide group.

A statistically significant difference was observed between the 2 groups in patients who received second-line therapy, with 30% of the cisplatin and etoposide group receiving second-line therapy and 22% of the carboplatin and etoposide group receiving second-line therapy.

Statistically significant factors associated with OS were age at diagnosis (HR, 1.01; 95% CI, 1.00-1.01), male sex (HR, 1.19; 95% CI, 1.06-1.33), ECOG performance status of 1 (HR, 1.37; 95% CI, 1.11-1.69), and ECOG performance status of 2 or higher (HR, 2.19; 95% CI, 1.77-2.71). The only statistically significant factor associated with real-world PFS was an ECOG performance status of 2 or higher (HR, 1.63; 95% CI, 1.33-2.00).

In an inverse propensity score weighted Cox model of average treatment effect on the treated with cisplatin as the reference, the HR for OS with carboplatin was 1.12 (95% CI, 0.99-1.29; P = .08) and for PFS was 1.08 (95% CI, 0.97-1.20; P = .15); in a model of average treatment effect, the HR for OS with carboplatin was 1.04 (95% CI, 0.92-1.17; P = .53), and for PFS it was 1.04 (95% CI, 0.93-1.17; P = .46).

“[Cisplatin and etoposide] and [carboplatin and etoposide] yield similar OS and PFS durations in a modern, real-world setting when adjusting for confounders. Careful patient selection is key for optimizing outcomes,” wrote lead study author Deepro Chowdhury, MD, from Princess Margaret Cancer Center in Toronto, Ontario, Canada, and coauthors. “This study confirms that either [cisplatin and etoposide] or [carboplatin and etoposide] are appropriate [first-line] chemotherapy options in [extensive-stage] SCLC. Future analysis of real-world efficacy in the immunotherapy era is warranted.”

This real-world analysis identified 4438 patients in the Canadian Small Cell Lung Cancer Database (CASCaDe), and 1365 patients were included in the analysis after meeting the inclusion criteria of having de novo extensive-stage SCLC diagnosed between 2000 and 2022 that received cisplatin and etoposide or carboplatin and etoposide in the first line of therapy.

The primary outcome of the analysis was OS; secondary end points included real-world PFS, rate of treatment completion and discontinuation due to toxicity, receipt of consolidative radiation therapy, and receipt of second-line therapy.

Notably, OS and real-world PFS were estimated using the Kaplan-Meier method, and the differences between both groups were compared via the log-rank test.

In the cisplatin and etoposide group, the median age at diagnosis was 64 years (IQR, 58.0-69.0) vs 69 years (IQR, 63.0-74.5) in the carboplatin and etoposide group; 53% and 52% of patients were male, respectively, 54% and 43% had an ECOG performance status of 1, 79% and 78% had no brain metastases at diagnosis, and 62% and 53% had no liver metastases at baseline.

Chowdhury D, Zhan L, Gill J, et al. Real-world comparison of carboplatin-etoposide vs cisplatin-etoposide in ES-SCLC. Presented at the International Association for the Study of Lung Cancer World Conference on Lung Cancer 2025; September 6-9, 2025; Barcelona, Spain. Abstract P2.100.