Dutch population-based study of treatment-free interval as determinant of second-line chemotherapy in ES-SCLC

For patients with recurrence after chemotherapy for extensive-stage small cell lung cancer (ES-SCLC), the length of the chemotherapy-free interval (CFI) may guide the choice of second-line treatment. A population-based study in The Netherlands investigated the impact of CFI on effectiveness of second-line treatment in ES-SCLC. The study included 261 patients diagnosed with recurrent ES-SCLC in 2022. Of these patients, 79 (30.3%) received topotecan, 153 (58.6%) received platinum rechallenge, and 29 (11.1%) received another systemic treatment. Median progression-free survival (PFS) was 2.0 and 3.9 months after topotecan and platinum rechallenge, respectively, while median overall survival (OS) was 3.8 months and 5.6 months, respectively. Multivariable analyses showed a lower risk of progression for patients with a CFI of 90-179 days receiving platinum rechallenge versus topotecan (HR 0.62; 95% CI 0.40-0.95) without a difference in OS (0.99; 0.65-1.52). Parametric survival models confirmed these results. The authors conclude that for patients with a CFI exceeding 90 days, platinum rechallenge represents a rational secondline strategy. These results remain relevant despite the introduction of first-line chemoimmunotherapy, as a substantial proportion of patients still relapse within 180 days. They are also relevant for healthcare settings where immunotherapy access is limited or unavailable.