Assessing Differences in Lymph Node Metastasis Based Upon Sex in Early Non-Small Cell Lung Cancer

Whether sex has any impact on the risk of lymph node (LN) metastasis (LNM) in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compared the risk of LNM between female and male patients with early-stage NSCLC so as to figure out whether sex-different extent of surgery may be justified for treating these patients.

We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic hilar and mediastinal LN dissection for clinical stage IA peripheral NSCLC from June 2014 to April 2019. Both multivariate logistic regression analysis and propensity score-matched(PSM) analysis were applied to compare the risk of LNM between female and male patients.

We finally included a total of 660 patients for analysis. In the analysis of unmatched cohorts, there was no significant different rate of LNM (12.4% Vs 13.9%, P=0.556), hilar/intrapulmonary LNM (8.4% Vs 10.7%, P=0.318) and mediastinal LNM(7.9% Vs 7.5%, P=0.851) between female and male patients. In the multivariate analysis, sex was not found to be an independent predictor of LN in these patients. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, there was still no significant different rate of LNM (13.8% Vs 13.4%, P=0.892), hilar/intrapulmonary LNM (9.1% Vs 11.2%, P=0.442) and mediastinal LNM (9.1% Vs 6.5%, P=0.289) between female and male patients.

Sex was not an independent predictor of LNM in early-stage NSCLC and there is no sufficient evidence justifying for sex-different extent of surgical resection for these patients.