The prognosis of small-sized non-small cell lung cancer with visceral pleural invasion after sublobar resection

Background: Sublobar resection is sometimes performed as a surgical treatment for small peripheral tumors. However, there is a question about whether sublobar resection is adequate treatment when visceral pleural invasion is diagnosed postoperatively. The purpose of this study was to evaluate the prognosis of patients with small-sized stage IB non-small cell lung cancer (NSCLC) after sublobar resection. Methods: From January 2010 to December 2018, 227 consecutive patients with eighth edition TNM stage IB NSCLC (per the joint staging system of the International Association for the Study of Lung Cancer and the American Joint Committee on Cancer) underwent curative surgery at a single center. Those patients were reviewed retrospectively. The clinicopathological characteristics and prognosis were compared between the sublobar resection group and the lobectomy group. The sublobar resection group included only smallsized (invasive component size cm) NSCLC. Results: In all study patients, clinicopathological characteristics between the sublobar resection and lobectomy groups were not different except in maximum standardized uptake value (SUVmax) and invasive component size. The 5-year recurrence-free survival (RFS) rate was 80.7% after sublobar resection and 73.4% after lobectomy (P=0.349). The 5-year overall survival (OS) rate was 87.3% after sublobar resection and 84.8% after lobectomy (P=0.503). In patients with small-sized NSCLC, the clinicopathological characteristics were not different between the sublobar resection group and the lobectomy group. The 5-year RFS rate was 80.7% after sublobar resection and 72.3% after lobectomy (P=0.417). The 5-year OS rate was 87.3% after sublobar resection and 91.2% after lobectomy (P=0.956). Sublobar resection was not a risk factor for recurrence in the multivariate analysis. Conclusions: The prognosis of sublobar resection in patients with small-sized stage IB NSCLC was comparable with lobectomy. Thus, additional completion lobectomy may not be essential in this setting, despite postoperative upstaging from T1 to T2a.