Risk Stratification and Adjuvant Chemotherapy Based on Clinical Risk Scores of Patients with Stage IB-IIA Non-Small Cell Lung Cancer

Abstract Background Despite the heterogeneity among patients with stage IB-IIA non-small cell lung cancer (NSCLC), clinical applicable model to identify those patients to receive adjuvant chemotherapy after radical resection is limited. We aimed to developed a clinical tool of benefits from adjuvant chemotherapy for risk stratification and individualized management in this heterogeneous patient population. Methods Between January 2008 and March 2018, patients with T2N0M0 NSCLC at Sun Yat-sen University Cancer Center were retrospectively retrieved. Survival curves were estimated by means of the Kaplan-Meier method and compared with the long-rank test. We used the Cox hazard regression models to identify the prognostic factors associated with the disease-free survival (DFS) and overall survival (OS). To reduce the possible effects of bias, propensity score matching (PSM) was implemented in a 1:1 ratio to. Subgroup analysis was further performed based on the quantized clinical risk score (CRS) derived from the prognostic variates and epidermal growth factor receptor (EGFR) mutation status. Results A total of 1063 patients with T2N0M0 NSCLC were enrolled in this retrospective study, 272 patients among them received adjuvant chemotherapy. Before PSM, Patients with a high-CRS (>1) had a significant worse OS and DFS. After PSM, the baseline characteristics of 270 pairs of patients were matched well. A significant improvement in OS was associated with adjuvant chemotherapy for patients with a high-CRS, while adjuvant chemotherapy was a positive independent prognostic factor for OS and DFS in patients with wild-type EGFR. The interaction analysis showed an apparent interaction effect between adjuvant chemotherapy and EGFR-activating mutations as well as chemotherapy regimens and histology.Conclusions Clinical risk score can be used to predict the prognosis of patients with stage IB-IIA NSCLC. Adjuvant chemotherapy could improve the outcome of patients after surgery, especially for those with clinical risk score over 1. Patients with non-squamous cell histology receiving pemetrexed plus platinum might benefit more, but not in those with EGFR-activating mutations.