Pathological Vascular Invasion and Tumor Differentiation Predict Cancer Recurrence in Stage IA Non-Small-Cell Lung Cancer After Complete Surgical Resection

Introduction: The appropriate therapeutic strategy and postoperative management for patients with stage IA non-small-cell lung cancer (NSCLC) still remain a matter of debate because of the prognostic heterogeneity of this population, including the risk of cancer recurrence. The objective of the current study was to identify the clinicopathological factors that affect overall prognosis and cancer recurrence of stage IA NSCLC. Methods: We reviewed the data of 532 patients in whom complete resection of stage IA NSCLC had been performed. Overall survival and recurrence-free proportion (RFP) were estimated using the Kaplan-Meier method. RFP was estimated from the date of the primary tumor resection to the date of the first recurrence or last follow-up. We performed univariate and multivariate analyses to determine the independent prognostic factors. Results: On multivariate analyses, three variables were shown to be independently significant recurrence risk factors: histological differentiation (hazard ratio [HR] = 1.925), blood-vessel invasion (HR = 1.712), and lymph-vessel invasion (HR = 1.751). On subgroup analyses combining these risk factors, the 5-year RFP was 91.3% for patients with no risk factors, 79.5% for those with either poorly differentiated carcinoma or vascular invasion, (p < 0.001 for both), and 62.9% for those with both poorly differentiated carcinoma and vascular invasion (p = 0.068). Conclusion: These results indicated that vascular invasion and tumor differentiation have a significant impact on the prediction of cancer recurrence in patients with stage IA NSCLC. Patients with these predictive factors of recurrence may be good candidates for adjuvant chemotherapy.