Comparing treatment strategies for stage I small cell lung cancer: A National Cancer Database study.

Abstract

8566 Background: Concurrent chemoradiotherapy is the standard of care for limited stage small cell lung cancer (SCLC). The ideal treatment strategy for stage I SCLC, however, is less clear. The purpose of this study is to compare outcomes for patients receiving definitive surgery, stereotactic body radiation therapy (SBRT), or external beam radiation therapy (EBRT) for stage I SCLC using the National Cancer DataBase (NCDB). Methods: Patients with a first primary diagnosis of stage I (T1-2 N0 M0) SCLC treated between 2004 and 2013 were identified in the NCDB. Patients were defined as having a first course of treatment of either definitive surgery, EBRT (45-74 Gy in 15-40 fractions) or SBRT (40-60 Gy in ≤5 fractions). Other recorded information included age, gender, race, T stage, Charlson-Deyo score, and use of chemotherapy. Overall survival (OS) was determined using the Kaplan-Meier method and Cox proportional hazards regression methods were used to estimate risk of overall mortality. Results: A total of 5944 patients with stage I SCLC were identified; of those, 2681 fit the study criteria. The median age of patients in the cohort was 68 years and median follow up was 26.6 months. Definitive surgery was performed in 944 (35%), EBRT in 1597 (60%), SBRT in 140 (5%), and chemotherapy was delivered in 2067 (77%). The 2- and 3-yr OS for the whole cohort was 62% and 50%; 72% and 62% for surgery, 56% and 44% for EBRT, and 56% and 40% for SBRT. Patient age, female gender, Charlson-Deyo score < 2, tumor size ≤3 cm, receipt of surgery and receipt of chemotherapy were all associated with improved OS. Comparing treatment strategies in a multivariate model, surgical resection demonstrated improved OS over EBRT (HR 2.0, p < 0.001) and SBRT (HR 1.66, p < 0.001). When excluding patients who underwent surgery, SBRT demonstrated improved OS compared with EBRT (HR 1.28, p = 0.04). In addition, receipt of chemotherapy resulted in improved OS (HR 0.66, p < 0.001). Conclusions: In this hospital-based registry study, definitive surgical resection and use of chemotherapy resulted in improved survival outcomes for patients with stage I SCLC. For patients who are not candidates for surgery, SBRT may offer a survival benefit compared with standard EBRT.