SESSION TYPE: Thoracic Surgery I
PRESENTED ON: Monday, October 22, 2012 at 11:15 AM - 12:30 PM
PURPOSE: Over the last two decades, many studies sought to find reliable predictors of N0 status in small-sized (≤2 cm in diameter) non-small cell lung cancers (NSCLC). However, the way of tumor size measurement was usually not standardized, and controversy remains as to whether systematic lymph node dissection should be performed in patients with subcentimeter tumors. Moreover, the correlations between lung adenocarcinoma subtypes in line with the new classification and lymph node metastasis have not yet been determined specifically in small peripheral tumors.
METHODS: We reviewed association between lymph node involvement and clinicopathologic variables in 243 small peripheral NSCLC with their size measured in fresh specimens before formalin fixation. Histologic subtypes of adenocarcinomas were classified according to the new International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) lung adenocarcinoma classification.
RESULTS: Incidence of N1 and N2 nodal involvement was 5.3% and 6.6%, respectively. N2 disease was present in a proportion of subcentimeter tumors (2 out of 53, 3.8%). No lymph node metastasis was revealed in squamous cell carcinomas, adenocarcinoma in situ, minimally invasive adenocarcinoma, lepidic predominant adenocarcinoma or invasive mucinous adenocarcinoma. Collectively, the five cell types accounted for 34.6% of all the small peripheral cases.
CONCLUSIONS: Precise measurement of tumor size in fresh tissues revealed that tumor size was not a reliable predictor of N0 status. However, through histologic classification, systematic lymph node dissection might be avoided in more than one third of small peripheral NSCLC.
CLINICAL IMPLICATIONS: Through analysis of 243 small peripheral non-small cell lung cancers with their size measured precisely in fresh specimens, we found that tumor size alone should not be criteria to rule out systematic lymph node dissection. However, through histologic classification, omission of systematic lymph node dissection might be an alternative in more than one third of small peripheral NSCLC.
DISCLOSURE: The following authors have nothing to disclose: Yang Zhang, Haiquan Chen, Jiaqing Xiang, Yawei Zhang, Yihua Sun, Hong Hu
No Product/Research Disclosure InformationFudan University Shanghai Cancer Hospital, Shanghai, China