The Necessity of Lymphadenectomy for Non-Small Cell Lung Cancer Smaller Than 6 mm in Solid Size

This study aimed to evaluate the necessity of lymph node sampling for specific non-small cell lung cancer (NSCLC).

Patients with small-size (≤2 cm) NSCLC who underwent surgical resection between 2009 and 2022 were retrospectively screened. The characteristics of patients with nodal metastasis were demonstrated. For selected patients, the perioperative and long-term outcomes with and without lymphadenectomy were compared.

Of the 2713 patients enrolled in this study, 75 (2.76 %) had involvement of nodules with a minimum solid size of 6 mm. No patient with pure ground glass opacity (0/945) had nodal metastasis, whereas 14 patients with part-solid nodules (14/1260, 1.11 %) and 61 patients with solid nodules (61/508, 12.01 %) had nodal involvement. Patients who had NSCLC with solid components smaller than 6 mm (n=1588) had no nodal metastasis. Of these patients, 339 underwent sublobar resection without lymphadenectomy (SRN0), 1056 received sublobar resection with lymphadenectomy (SRN1), and 190 received lobectomy with lymphadenectomy (LRN1). The patients with SRN0 had a shorter operating time, less volume of drainage, a lower incidence of chylothorax (0 % vs 0.6 % vs. 2.1 %; P = 0.012) and air leakage, as well as a shorter postoperative hospital stay (3 vs. 4 vs. 4 days; P < 0.001) than those with SRN1 or LRN1. The 5-year recurrence-free survival was 100 % for the patients with SRN0, 99.2 % for those with SRN1, and 98.5 % for those with LRN1 (P = 0.370).

Lymphadenectomy may be unnecessary for NSCLC smaller than 6 mm in solid size. Sublobar resection without lymphadenectomy had favorable effects on postoperative complications and fast recovery with no compromise of long-term outcomes.