Segmentectomy for early-stage non-small-cell lung cancer with invasive characteristics: the definitions of invasiveness and feasibility of segmentectomy.

Abstract

Kagimoto recently compared the survival difference between segmentectomy and lobectomy by retrospectively analysing 321 patients with early-stage small-sized non-small-cell lung cancer (NSCLC) with invasive characteristics, including lymphatic invasion, vascular invasion, pleural invasion and/or lymph node (LN) metastasis [1]. Comparable cumulative incidences of recurrence were found between segmentectomy and lobectomy, suggesting that segmentectomy might be feasible for clinically early-stage NSCLC regardless of invasiveness. The authors conducted propensity score matching analysis to narrow the inter-group heterogeneity and employed cumulative incidences of recurrence to reduce the impact of competing events. However, whether this conclusion can assist intraoperative decision-making remains a question. Other than pleural invasion and LN metastasis, although tumours with lymphatic invasion and/or vascular invasion were referred to as poor prognosis [2], they were not identified as upstaging descriptors in the eighth edition of the TNM classification and might not definitively instruct the treatment strategies. Previous research indicated that lymphatic invasion and vascular invasion were associated with several clinicopathologic characteristics, such as tumour size and adenocarcinoma subtypes [2]. In this way, the determinative risk factors, upstaging descriptors, and the indications of segmentectomy for early-stage small-sized NSCLC remain to be investigated in prospective studies. Moreover, the potential confounding factors were likely to be attached to the importance and explored in subgrouping analysis, including adjuvant treatment and the number of dissected lymph nodes [3].