Adjuvant Chemotherapy in Patients with Node-Negative Non-Small Cell Lung Cancer with Satellite Pulmonary Nodules in the Same Lobe

Background: According to the eighth TNM (tumor-node-metastasis) staging system, the presence of separate tumor nodules in the same lobe is designated as a T3 descriptor. However, it remains unclear whether adjuvant chemotherapy confers survival advantages in this setting. Methods: We retrospectively identified 142 pathologic T3N0M0 patients with additional pulmonary nodules in the same lobe from a single-institutional database from 2004 to 2019. The main outcomes were overall survival and recurrence-free survival. Multivariable Cox regression was used to identify the benefit of adjuvant chemotherapy while adjusting for other variables. Results: Sixty-one patients received adjuvant chemotherapy (adjuvant group) and 81 patients did not receive adjuvant therapy after surgery (surgery-only group). There were no demonstrable differences between the 2 groups regarding hospital mortality and postoperative complications, indicating that treatment selection had not significantly occurred. However, the use of adjuvant chemotherapy was associated with improved 5-year overall survival (70% vs. 59%, p=0.006) and disease-free survival (60% vs. 46%, p=0.040). A multivariable Cox model demonstrated that adjuvant chemotherapy was associated with a survival advantage (adjusted hazard ratio, 0.54; p<0.001). In exploratory analyses of subgroups, the effect of adjuvant chemotherapy seemed to be insufficient in those with small main tumors (<4 cm). Conclusion: Adjuvant chemotherapy was associated with better survival in T3 cancers with an additional tumor nodule in the same lobe. However, the role of adjuvant chemotherapy in patient subgroups with small tumors or those without risk factors should be determined via large studies.