Clinical significance of post‑progression survival after chemoradiotherapy on overall survival in limited‑disease small cell lung cancer

Overall survival (OS) among patients with limited-disease small-cell lung cancer (LD-SCLC) receiving chemoradiotherapy can be significantly influenced by subsequent treatments. Thus, the present study aimed to examine the interplay between progression-free survival (PFS), post-progression survival (PPS) and OS in patients with LD-SCLC undergoing chemoradiotherapy. This study retrospectively analyzed 84 patients with relapsed LD-SCLC who received chemoradiotherapy between April 2007 and June 2021. The correlations between PFS and OS as well as PPS and OS post-chemoradiotherapy were analyzed at the individual patient level. Spearman's rank correlation and linear regression analyses revealed a robust correlation between PPS and OS (r=0.76; P<0.05; R²=0.85). PFS was moderately correlated with OS (r=0.57; P<0.05; R²=0.25). Furthermore, the presence of liver metastases upon relapse and the administration of platinum re-challenge chemotherapy were significantly associated with PPS (P<0.05). The analysis of relationships between OS and PFS as well as OS and PPS in this patient cohort revealed that OS was more strongly correlated with PPS than PFS. These findings suggest that factors such as liver metastases at relapse and the administration of platinum re-challenge chemotherapy may influence PPS.