Comparative survival outcomes among histological subtypes of non-small cell lung cancer in the United States.

e20072 Background: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. However, a comparative survival impact of its histological variants remains understudied in the US population. Methods: Using the National Cancer Database, we identified patients diagnosed with NSCLC histological subtypes (Adenocarcinoma, Adenosquamous, Squamous, Large cell, Pseudosarcomatous, Anaplastic, Pleomorphic, Giant cell, & Spindle cell carcinomas) between 2010 and 2017. Strobe guidelines were followed for reporting purposes. Unadjusted median overall survival (mOS) was estimated using Kaplan-Meier survival analysis. A multivariate regression analysis was conducted with an accelerated failure time model to estimate hazard ratios adjusted for covariates. Covariates included were age, sex, race, tumor grade, TNM stage, Charlson Comorbidity Index, insurance status, year of diagnosis, facility type, and treatment modality. Adenocarcinoma served as the reference arm for HR calculations. Results: A total of 708,671 patients were included in the study. Of these, 481,991 (68.01%) were aged ≥65 years, 344,131 (48.6%) were female, 608,012 (85.8%) were white, and 458,591 (64.7%) had Medicare insurance. Adenocarcinoma (n= 443,900; 62.64%) demonstrated the best outcome with mOS of 24.4 months (p<0.05), followed by Pleomorphic carcinoma (n= 1,089; 0.15%) with mOS of 16.0 months (HR = 1.14, p<0.01). Adenosquamous carcinoma (n= 12,211; 1.72%) had mOS of 19.0 months (HR = 1.18, p<0.01). Squamous cell carcinoma (n= 240,447; 33.93%) demonstrated an mOS of 17.25 months (HR = 1.23, p<0.01), while large cell carcinoma (n= 6,417; 0.91%) showed an mOS of 9.17 months (HR = 1.26, p<0.01). Of all, the worst outcomes were observed in Pseudosarcomatous carcinoma (n= 3,080; 0.43%), with a mOS of 5.98 months (HR = 1.53, p<0.01). Other histologies associated with poorer prognosis included Undifferentiated/anaplastic carcinoma (n= 399; 0.06%) with mOS of 5.98 months (HR = 1.32, p<0.01), Giant cell carcinoma (n= 395; 0.06%) with mOS of 7.16 months (HR = 1.32, p<0.01), and Spindle cell carcinoma (n= 733; 0.10%) with mOS of 6.37 months (HR = 1.35, p<0.01). Conclusions: NSCLC histological variants exhibit distinct survival outcomes, with adenocarcinoma showing the best prognosis and Pseudosarcomatous carcinoma the poorest. These results stress the importance of further research to develop therapies tailored to specific histological variants. Histology HR CI P value Adenocarcinoma ref Pleomorphic 1.14 1.06-1.22 <0.01 Adenosquamous 1.18 1.15-1.20 <0.01 Squamous cell 1.23 1.22-1.24 <0.01 Large cell 1.26 1.23-1.30 <0.01 Pseudosarcomatous 1.53 1.47-1.59 <0.01 Anaplastic 1.32 1.19-1.48 <0.01 Giant cell 1.32 1.19-1.48 <0.01 Spindle cell 1.35 1.25-1.46 <0.01