Abstract
Given the limited evidence on prognostic factors specifically for older patients with extensive-stage small cell lung cancer (ES-SCLC), a population with distinct clinical characteristics, this study aimed to validate whether previously reported prognostic indicators retain their predictive value in this vulnerable group. A retrospective analysis was conducted on data from 270 older ES-SCLC patients who received treatment at the Fourth Hospital of Hebei Medical University between December 2016 and June 2024. By the final follow-up date of October 15, 2024, 212 deaths had been recorded. The median progression-free survival (mPFS) was 6.7 months (95% confidence interval [CI] 6.0-7.4), and the median overall survival (mOS) was 13.1 months (95% CI 11.8-14.4). For PFS, univariate and multivariate Cox analyses identified first-line chemotherapy (CT) and old-old (≥ 75 years) as independent adverse prognostic factors. For OS, old-old, a positive smoking history, bone metastasis, and high-lactate dehydrogenase (> 250 U/L) were identified as significant adverse prognostic factors. Notably, high-pro-gastrin-releasing peptide (ProGRP) (> 69.2 pg/mL) was significantly associated with an increased risk of death during the follow-up period beyond 10 months (HR = 1.85, 95% CI 1.05-3.26, p = 0.032); conversely, no significant association was observed within the initial 10 months of follow-up (HR = 0.84, 95% CI 0.44-1.60, p = 0.604). In conclusion, these findings not only corroborate the prognostic value of previously identified risk factors in older patients with ES-SCLC but also demonstrate that the prognostic impact of ProGRP is distinctly time-dependent.