Large cell carcinoma with rhabdoid phenotype: Demographics, treatment, and survival in the NCDB.

Abstract

e20078 Background: Large cell carcinoma with rhabdoid phenotype (LCC-RP) constitutes <1% of lung malignancies and is associated with a poorer prognosis than classic LCC, characterized by aggressive biologic behavior with early widespread metastasis and rapid progression. The median survival and five-year survival rate among LCC patients are eight months and 15.6%, respectively. Case series report LCC-RP patients as primarily male (ages 35-70) and often presenting with advanced disease stages (n=11). Since comprehensive survival data remain unreported, this study uses the NCDB to analyze the demographic profile and survival outcomes of patients with LCC-RP. Methods: A retrospective cohort study using the 2004–2020 National Cancer Database to identify patients with histologically confirmed LCC-RP (ICD-O-3 code 8014). Variables included demographics (age, sex, race, Hispanic origin, educational attainment, insurance status, treatment facility type, Charlson-Deyo comorbidity score), clinical characteristics (stage at diagnosis, primary tumor site), treatment modalities (surgical resection, chemotherapy, radiation therapy), and survival outcomes. Incidence patterns were evaluated using regression analysis. Results: The study cohort included 293 patients with LCC-RP. No substantial temporal trend in annual incidence was observed (R² = 0.033). Stage IV disease was most common at diagnosis (37.5%), with upper lobe predominance (31.1%). Most patients were male (60.8%), non-Hispanic (93.2%), and White (83.3%), with a mean age of 65.4 years. Patients predominantly resided in metropolitan areas (84.7%) and were evenly distributed across income quartiles, with the largest proportion in the ≥$74,063 quartile (28.2%). Most were insured by Medicare (51.9%), and comprehensive community cancer programs treated the plurality of patients (42.5%). Most patients (64.8%) did not undergo surgical resection. Chemotherapy was the most common treatment (42%), followed by radiation therapy (35.2%). Median survival was 62.7 months, with five-year and ten-year survival rates of 34.1% and 26.7%, respectively. Conclusions: This is the first NCDB analysis of large cell carcinoma with rhabdoid phenotype, providing demographic, treatment, and overall survival data from a large national cohort. Most patients were male, non-Hispanic, and white, consistent with the gender distributions in prior case series. Patients were evenly distributed across income quartiles, with the largest proportion in the highest quartile. They predominantly lived in metropolitan areas and were most commonly treated at comprehensive community cancer programs. Median survival (62.7 months) dramatically exceeded survival estimates reported in prior case series. Further research is needed to analyze factors contributing to improved survival and the impact of demographic, socioeconomic, and treatment variables on outcomes.