Prognostic factors for survival in extensive-stage small cell lung cancer: An Italian real-world retrospective analysis of 244 patients treated over the last decade.

Background: Potential relationships with the prognosis of patients with extensive-stage non-small cell lung cancer (ES-SCLC) have been investigated without valid results.

Methods: A retrospective analysis of real-world data of consecutive patients with ES-SCLC admitted to our Medical Thoracic Oncology Unit was carried out from 2010 to 2020, focusing on identification of prognostic factors. Kaplan-Meier analysis was used to represent progression-free survival (PFS) and overall survival (OS). Univariable and multivariable Cox models were used to investigate prognostic factors.

Results: The analysis included 244 patients. The median OS was 8 months (95% confidence interval [CI]: 8-10) and the median PFS was 5 months (95% CI: 5-6). The univariable analysis showed that factors associated with shorter OS were older age (p = 0.047), TNM stage 4 versus 3 (p < 0.001), Eastern Cooperative Oncology Group (ECOG) performance status (PS) 1 and 2 versus 0 (p < 0.001), and >2 metastatic sites (p = 0.004). Mediastinal radiotherapy (RT) (p < 0.001), >1 irradiated site (p = 0.026), 3 and 4 chemotherapy (CT) lines versus 1 (p = 0.044 and 0.001, respectively), prophylactic cranial irradiation (PCI) (p < 0.001), and surgery (p = 0.001) correlated with longer OS. The multivariable analysis revealed statistically significant associations for TNM, ECOG PS 2 versus 0, number of CT lines, PCI, and surgery. A total of 23 patients (9.4%) survived ≥24 months, 39% of whom had received four CT lines and 48% had mediastinal RT.

Conclusions: Our data suggest that tumor burden, PS, and mediastinal RT strongly correlate with outcome. With the addition of immunotherapy to CT, the identification of new biomarkers as predictive factors is urgently required.