137TiP Adaptive maintenance therapy guided by multimodal biomarkers after first-line targeted therapy plus chemotherapy for advanced EGFR-mutant non-small cell lung cancer: A multicenter, randomized controlled phase II study

Background: Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small cell lung cancer (NSCLC), accounting for only 0.1%-0.4% of lung cancers.Studies have shown that PSC is more aggressive than other non-small cell lung cancers and has a worse prognosis.Despite numerous efforts to study the features of PSC, few large population-based studies have specifically characterized long-term incidence trends of PSC.Therefore, this study was conducted to provide an overview of PSC incidence and survival outcomes based on data from the SEER database. Methods:We performed a retrospective analysis using the SEER database for patients with histologically confirmed pulmonary sarcomatoid carcinoma between 2004 and 2022.Incidence rates, cancer-specific survival (CSS), and demographic and clinical characteristics were assessed.Incidence rate ratios (IRRs) were calculated using the Tiwari method.Joinpoint regression was used to assess temporal trends, while Kaplan-Meier and Cox proportional hazard models analyzed survival outcomes.Data were analyzed using the latest version of Jamovi.Results: A total of 2560 patients with PSC were identified, 42.7% were female and 57.3% male; 82.4% were White, 11.7% Black, and 5.9% Asian/Pacific Islander.At diagnosis, 52.6% presented with metastases and 17.7% with localized disease.Median CSS was 9 months; 3-year and 5-year CSS were 31.4% and 27.7%, respectively.Incidence declined from 0.13 (2004) to 0.10 (2022) per 100,000 (APC -1.6).Significant decreases occurred in White, metropolitan, and male populations, while rates stagnated in Black, female, and rural groups.Localized disease showed significantly better survival (median 144 months vs. 3 months for metastases; HR 0.16, p<0.001).Male sex (HR 1.20) and age >50 (HR 1.39) were independent predictors of poor prognosis.Conclusions: PSC incidence is declining overall but remains stagnant in Black, female, and rural populations.Survival remains poor, particularly for males, older patients, and those with metastases, emphasizing the need for early detection and targeted risk reduction.