Survival in limited disease small cell lung cancer according to N3 lymph node involvement

Abstract

Background/Aim: There are several definitions of limited disease (LD) in small cell lung cancer (SCLC), differing with respect to N3 disease accepted. We analyzed patients from a randomized trial comparing two schedules of thoracic radiotherapy (TRT) in LD SCLC to investigate whether there were survival differences between N3 subcategories (n=144). Patients and Methods: Patients with a baseline CT scan available were analysed. Patients received four courses of cisplatin/etoposide and TRT of 45 Gy/30 fractions (twice daily) or 42 Gy/15 fractions (once daily). Results: Median overall survival (OS) was 23.3 months in the whole cohort. N3-patients (n=37) had shorter survival than those with N0-2 (16.7 vs. 33.0 months; p<0.001). There were no significant OS-differences between the N3 subcategories, but patients with metastases to two or more N3 regions had shorter survival than other N3 patients (13.4 vs. 19.9 months; p=0.011). Conclusion: There were no survival differences between the N3 subcategories, suggesting that all N3 disease should be considered as LD.