Effects of surgery on survival of elderly patients with stage I small-cell lung cancer: analysis of the SEER database.

Abstract

Surgery improves survival of small-cell lung cancer (SCLC) patients in early stage. However, the role of surgery in the elderly stage I SCLC patients is not well established. We designed this retrospective study to explore the efficacy of surgery on survival of this subset population. Elderly patients aged ≥ 75years with stage I SCLC diagnosed histologically from 1998 to 2013 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Included patients were divided into surgery group (received surgery, accompanied by chemotherapy, radiotherapy, or both or neither), non-surgical group (only received radiotherapy, chemotherapy, or combination), and untreated group. Overall survival (OS) and lung cancer-specific survival (LCSS) were compared among the three groups by the Kaplan-Meier analysis. Cox proportional hazards regression was used to identify factors associated with survival. A total of 983 patients were included. Among all of the patients, 24.0% patients received surgery, 46.6% patients received non-surgical treatment, and 29.4% patients received no treatment. The 5-year OS rates of surgery, non-surgical and untreated groups were 31%, 12% and 6%, respectively (P < 0.0001). In multivariable analysis, surgery was an important factor that improved OS when compared with non-surgical treatment (HR 0.554; 95% CI 0.458-0.670 [P < 0.0001]). In subgroup analysis, surgery remained an independent factor for OS among patients aged 75-79years (HR 0.506; 95% CI 0.391-0.655 [P < 0.0001]) and 80-84years (HR 0.544; 95% CI 0.388-0.763 [P < 0.0001]), while did not reach statistical significance when compared to non-surgical treatment for patients age ≥ 85years (HR 0.914; 95% CI 0.507-1.650; [P = 0.766]). Surgical resection significantly improved OS in stage I SCLC patients aged 75-84years in our study, but further exploration in larger prospective clinical trials is needed.