An NCDB analysis on the demographic, treatment, and survival of small cell carcinoma with fusiform cells of the lungs.

Abstract

e20137 Background: Small cell carcinoma with fusiform cells (SCC-FC), commonly originating in the lungs, is clinically characterized by spindle-shaped tumor cells and represents a highly aggressive morphological variant of the general small cell carcinoma. Though survival statistics for SCC-FC are limited due to its rarity, the 98% five-year mortality rate of general small cell carcinoma suggests possible similarity aggressive behavior. Given the rarity of this disease, we aim to provide insights into its epidemiology by analyzing the National Cancer Database (NCDB) to characterize sociodemographic factors of patients diagnosed with SCC-FC. Methods: A retrospective cohort study using the 2004–2020 NCDB included patients with histologically confirmed cases of SCC-FC (N = 304), ICD-O-3 code - 8043. Demographic and clinical variables—age, sex, race, Hispanic ethnicity, mortality rate, treatment methods, and Charlson/Deyo comorbidity score—were analyzed using descriptive statistics, and incidence trends were evaluated using regression analysis. Survival analysis was conducted using Kaplan-Meier estimates. Results: A total of 304 patients with SCC-FC were identified in the NCDB between 2004 and 2020 with a decreasing incidence (R² = 0.6). Most patients were female (54.3%), White (91.1%), and non-Hispanic (93.1%), with the mean age at diagnosis being 67.5 years old (SD = 0.59). The primary payor at diagnosis was Medicare (60.5%), followed by private insurance/ managed care (26.3%). The median household income quartiles and distribution are as follow, 21.0% within Q1 ( < $46,277), 36.9% in Q2 ($46,227 - $57,856), 24.1% in Q3 ($57,857 - $74,062), and 17.9% in Q4 ($74,063 or more). The upper lobes of the lungs are the most common primary site location with most cases being diagnosed at Stage IV (52.0%) and Stage III (22.4%); most of the patients (57.2%) had a Charlson-Deyo Score of 0. The mean tumor size is 47mm (SD = 5.09). The vast majority (95.7%) of patients received no surgical procedure at the primary site, instead 51.6%, 61.8%, and 0.7% of patients received radiation, chemotherapy, and immunotherapy as their primary treatment, respectively. The 2, 5, and 10 year survival rates are 13.5%, 5.9%, and 3.7% respectively, with the mean survival time being 18.231 months (SD = 2.26). Conclusions: To the best of our knowledge this is the first NCDB analysis on SCC-FC. The upper lobes were the most common primary site, differing slightly from prior reports that emphasize central lung involvement. According to previously published papers chemotherapy does present itself as the primary treatment option the vast majority of patients use for small cell lung cancer, which aligns with the data we have for the variant with fusiform cells. This analysis is the first to suggest that most SCC-FC patients do not receive surgery at the primary site and instead, are primarily treated using radiation and chemotherapy.