The Role of Adjuvant Therapy Following Surgical Resection of Small Cell Lung Cancer: A Multi-Center Study

PURPOSE: This multi-center, retrospective study was conducted to evaluate the long-term survival in patients who underwent surgical resection for small cell lung cancer (SCLC) and to identify the benefit of adjuvant therapy following surgery. MATERIALS AND METHODS: The data of 213 patients who underwent surgical resection for SCLC at four institutions were retrospectively reviewed. Patients who received neoadjuvant therapy or an incomplete resection were excluded. RESULTS: The mean patient age was 65.29±8.93 years, and 184 patients (86.4%) were male. Lobectomies and pneumonectomies were performed in 173 patients (81.2%), and 198 (93%) underwent systematic mediastinal lymph node dissections. Overall, 170 patients (79.8%) underwent adjuvant chemotherapy, 42 (19.7%) underwent radiotherapy to the mediastinum, and 23 (10.8%) underwent prophylactic cranial irradiation. The median follow-up period was 31.08 months (interquartile range, 13.79 to 64.52 months). The 5-year overall survival (OS) and disease-free survival were 53.4% and 46.9%, respectively. The 5-year OS significantly improved after adjuvant chemotherapy in all patients (57.4% vs. 40.3%, p=0.007), and the survival benefit of adjuvant chemotherapy was significant in patients with negative node pathology (70.8% vs. 39.7%, p=0.004). Adjuvant radiotherapy did not affect the 5-year OS (54.6% vs. 48.5%, p=0.458). Age (hazard ratio [HR], 1.032; p=0.017), node metastasis (HR, 2.190; p < 0.001), and adjuvant chemotherapy (HR, 0.558; p=0.019) were associated with OS. CONCLUSION: Adjuvant chemotherapy after surgical resection in patients with SCLC improved the OS, though adjuvant radiotherapy to the mediastinum did not improve the survival or decrease the locoregional recurrence rate.