Uncertain Resection in Lung Cancer: A Comprehensive Review of the International Association for the Study of Lung Cancer Classification

Objective: We aimed to explore the relevance of uncertain resection in lung cancer. Methods: We performed an exhaustive literature review of all studies comparing prognosis after resection according to IASLC classification. Results: Systematic review led to select 64 original studies included in this review. R(un) reclassification was mostly caused by a lack of hilar or mediastinal node dissection, or because of metasta-sis in the highest node. R(un) is a strong factor for higher recurrence and mortality, while its effects seem limited in early stages. Carcinoma in situ at bronchial margin resection (CIS BRM) does not show effect on survival, while positive pleural cytology (Cy+) and positive highest mediastinal lymph node (HMLN+) appear to be highly pre-dictive of recurrence and death. Conclusion: The R(un) classification of the IASLC 2005 appears highly relevant, espe-cially in locally advanced stages IIb-IIIA, and helps to discriminate patients with poor prognosis despite being classified as R0 according to UICC classification. The use of this more precise classification would allow for better stratification of recurrence risk and more effective use of adjuvant therapies. Cy+ patients should receive adjuvant chemotherapy, while CIS BRM patients could likely benefit from endoscopic surveil-lance to detect local recurrences. HMLN+ patients should be considered at high risk of recurrence, and adjuvant radiochemotherapy should be considered.