Breaking barriers for patients with stage IV non-small cell lung cancer with brain metastases: Insight into the impact of immunotherapy on survival and survival disparities.

Abstract

8545 Background: Brain metastases (BM) correlate with poor prognosis, occurring in 10% of non-small cell lung cancer (NSCLC) patients (pts) at diagnosis and up to 40% over the disease course. Immunotherapy (IO) with or without chemotherapy has become the new standard of care for stage IV NSCLC. However, the survival benefit of IO in pts with BM remains unclear as most studies are limited to small sample sizes or highly selected pts with asymptomatic or treated BMs. This study represents the largest real-world data analysis evaluating the survival benefits of IO in stage IV NSCLC pts with BM. Methods: Demographics, clinical features, and survival were analyzed in stage IV NSCLC pts with BM from the National Cancer Database (NCDB) from 2014-2020. A multivariate Cox proportional hazards modeling assessed factors impacting mortality. Results: Of 204,249 pts with stage IV NSCLC, 30% had BM. The mean age was 68 years, with 54% male. Most pts were White (82%), followed by Black (12%) and Asian (3.1%). Government insurance covered 70% of pts, and 26% had private insurance. Adenocarcinoma was the predominant histology (62%), followed by squamous cell carcinoma (SCC) (20%). Liver and bone metastases were observed in 19% and 42% of pts, respectively. Among pts with BM, 18% received immunotherapy, 53% received chemotherapy, 66% received whole-brain radiation, and 18% received limited-brain radiation. Multivariate Cox analysis showed that pts receiving IO had a 46% lower mortality risk compared to not receiving IO (HR: 0.54, 95% CI: 0.51–0.56, p < 0.001), demonstrating the independent benefit of IO in pts with BM, regardless of brain radiation or chemotherapy. Females had a lower mortality risk than males (HR: 0.88, 95% CI: 0.85–0.91, p < 0.001). Asian (HR: 0.71, 95% CI: 0.64–0.79), Hispanic (HR: 0.76, 95% CI: 0.65–0.89), and Black pts (HR: 0.88, 95% CI: 0.84–0.93) had improved survival as compared to White. Pts with private insurance have lower mortality risk (HR: 0.94, 95% CI: 0.90–0.98), compared to lack of insurance (HR: 1.19, 95% CI: 1.08–1.31). SCC was linked to worse survival (HR: 1.28, 95% CI: 1.22–1.35). Conclusions: IO significantly improves survival in pts with NSCLC with BM, regardless of brain radiation therapy or chemotherapy. However, survival disparities based on histology, insurance status, and demographic factors persist, highlighting the need for more equitable treatment strategies.