Perioperative chemotherapy is not associated with improved survival in stage I pleomorphic lung cancer

Pulmonary pleomorphic carcinoma represents an understudied, rare, and aggressive histologic subtype of non-small cell lung cancer. Better understanding of rare disease subtypes allows for improved individualization of patient care. This study aimed to evaluate current trends in treatment and survival of pleomorphic carcinoma.

The National Cancer Database was used to identify patients with staged, pleomorphic carcinoma and adenocarcinoma between 2004 and 2015. Patient characteristics and treatments were compared using χ² tests. Cox proportional hazard models examined survival by stage after controlling for confounders. Propensity score matched Kaplan-Meier curves estimated survivor functions stratified by stage. Differences in survival following treatment for stage I pleomorphic carcinoma with surgery alone versus surgery plus chemotherapy were compared with Cox proportional hazard models and Kaplan-Meier survival curves.

One thousand four hundred eight patients with pleomorphic carcinoma and 607,561 patients with adenocarcinoma were identified. Pleomorphic carcinoma accounted for 0.1% of all non-small cell lung cancers. Pleomorphic disease had poorer overall 5-year survival compared with adenocarcinoma for stages I through IV (49.4% vs 59.1%, 34.5% vs 43.8%, 16.9% vs 28.4%, and 5.7% vs 7.8%, respectively; P < .0047 for all). Perioperative chemotherapy was used more frequently for pleomorphic disease (17.5% vs 6.1%; P < .001). For stage I pleomorphic cancer, treatment with surgery alone (n = 253) and surgery with chemotherapy (n = 57) had overall 5-year survival rates of 55.2% and 53.7%, respectively, and were not significantly different (P = .2868).

Pulmonary pleomorphic carcinoma is rare and aggressive, with worse survival when compared with adenocarcinoma. Perioperative chemotherapy has not demonstrated significant survival benefits in stage I pleomorphic cancer.