Assessing the prognostic impact of the International Association for the Study of Lung Cancer proposed definitions of complete, uncertain, and incomplete resection in non-small cell lung cancer surgery

OBJECTIVE: The aim of this study was to assess the prognostic impact of the definitions of complete, uncertain, and incomplete resection in non-small cell lung cancer (NSCLC) surgery, as proposed by the International Association for the Study of Lung Cancer (IASLC). PATIENTS AND METHODS: Single institution retrospective study of consecutive patients undergoing surgery for NSCLC between 1998 and 2007. Complete resection was defined by absence of gross and microscopic residual disease; systematic nodal dissection; no extracapsular extension in distal lymph nodes; and negativity of the highest mediastinal node removed. An uncertain resection was defined by free resection margins, but one of the following applied: lymph node evaluation less rigorous than systematic nodal dissection; positivity of the highest mediastinal node removed; presence of carcinoma in situ at the bronchial margin; positive pleural lavage cytology. A resection was defined incomplete by presence of residual disease; extracapsular extension in distal lymph nodes; positive cytology of pleural or pericardial effusions. Follow-up was complete and all patients were followed up until death or for a minimum period of 5 years. Overall survival (OS) was analyzed using Kaplan-Meier method, log rank test, and Cox proportional hazards model. RESULTS: A total of 1277 patients were identified. One thousand and three patients (78.5%) underwent complete resection, 185 (14.5%) underwent uncertain resection, and 89 (7.0%) underwent incomplete resection. Both uncertain and incomplete resection were associated with significantly worse OS when compared with complete resection (hazard ratio: 1.69 and 3.18, respectively; both p=0.0001). Median OS and 5-year survival rate were 80.1, 39.9, 17.3 months and 58.8%, 37.3%, 15.7% in patients undergoing complete, uncertain, and incomplete resection, respectively. CONCLUSION: The present analysis suggests that in patients undergoing surgery for NSCLC, the IASLC definitions of complete, uncertain, and incomplete resection are associated with statistically significant differences in survival.