Postoperative chemotherapy significantly improves survival of elderly patients with stage IB-II non-small cell lung cancer: A population-based study.

Background: There is scant evidence-based information about survival benefits of postoperative chemotherapy in elderly patients with early-stage non-small cell lung cancer (NSCLC). The purpose of this study is to compare the overall survival (OS) and cancer-specific survival (CSS) rates of surgery alone versus postoperative chemotherapy in patients aged ≥70 years with stage I-II NSCLC.

Methods: Elderly patients aged ≥70 years diagnosed with stage I-II NSCLC were selected from the Surveillance, Epidemiology, and End Results (SEER) database from January 1, 2010 to December 31, 2015. OS and CSS were compared between the two groups utilizing overlap weighting analysis, inverse probability of treatment weight (IPTW), and propensity score matching (PSM).

Results: Of the 7193 included patients with stage I-II NSCLC who are more than 70 years old, 681 patients (9.5%) received postoperative chemotherapy and 6512 patients (90.5%) received surgery-alone. Median OS was 77 months in postoperative chemotherapy group versus 79 months in surgery-alone group (p = 0.89). The result of IPTW analysis showed the similar results. The probability of patients choosing chemotherapy increased with the AJCC stage and Grade increasing (p < 0.001) and decreased with the growth of age (p < 0.001). The results of subgroup analysis showed that the survival rate of stage IA patients decreased significantly after postoperative chemotherapy (p < 0.01) while the survival rate of stage IB-II patients increased significantly (p < 0.01). At the same time, we found that patients in the postoperative chemotherapy group tended to have better OS than those in the surgery-alone group with the grade and tumor size increasing.

Conclusion: The results of this study indicated that postoperative chemotherapy could significantly improve the survival of stage IB-II NSCLC patients aged ≥70 years, and decrease the survival of stage IA patients.