Validation of the lung inmune prognostic (LIPI) index in first-line immunotherapy treatment of small cell lung carcinoma

BackgroundSCLC presents challenges due to its aggressiveness and the limited treatment options available. Immunotherapy is promising, but selecting the suitable patients remains a challenge. LIPI index, which has been validated in NSLC, lacks thorough validation in SCLC. This multicenter study aimed to validate LIPI for predicting outcomes in advanced SCLC patients receiving first-line chemo-immunotherapy.MethodsA multicenter study conducted from January 2018 to December 2023 involved patients with SCLC who received first-line chemo-immunotherapy. LIPI index was calculated based on baseline LDH levels and pretreatment dNLR. Patients were stratified into three risk groups: good (0 factors), intermediate (1 factor), and poor (2 factors). The primary endpoint was OS, with secondary endpoints including PFS. Survival analysis utilized Kaplan-Meier curves and Cox proportional hazards models.ResultsIn our cohort of 273 SCLC patients, the majority were males (71.4%) with an ECOG performance status of 0/1 (84.9%). Common metastatic sites included the liver (41.8%), bones (42.9%), adrenal glands (28.6%), and central nervous system (20.9%). High LDH levels were observed in 65.2%, and NLR >3 in 36.6%. The mean number of cycles of atezolizumab administered was 8.6 (SD 3.9-8), with 70% of patients showing a partial response. Median OS was 9.6 months (95% CI, 8.6-10.6), and median PFS was 4.8 months (95% CI, 4.2-5.4). LIPI stratified patients into good (31.9%), intermediate (44.7%), and poor (23.4%) groups. Median OS differed significantly among these groups: 11.4 months (95% CI, 8.4-14.3) for good, 9.5 months (95% CI, 8-11) for intermediate, and 8.6 months (95% CI, 7.6-9.6) for poor LIPI scores (p = 0.004). Median PFS also varied: 5.2 months (95% CI, 4.3-6.2) for good, 4.9 months (95% CI, 3.9-5.9) for intermediate, and 4.4 months (95% CI, 3.7-5.2) for poor LIPI groups (p = 0.38).ConclusionsThe study demonstrated a significant correlation between LIPI categories and survival outcomes, indicating superior OS in patients with good LIPI scores compared to intermediate or poor scores. These findings highlight the potential of LIPI as a prognostic tool for guiding treatment strategies and risk assessment in SCLC patients.Legal entity responsible for the studyThe authors.FundingHas not received any funding.DisclosureAll authors have declared no conflicts of interest.