Surgical Consideration Based on Lymph Nodes Spread Patterns in Patients with Peripheral Right Middle Non-small Cell Lung Cancer 3 cm or Less

Background The optimal extent of lung resection and lymph nodes dissection for peripheral early-stage right middle non-small cell lung cancer (NSCLC) still remains controversial. In this study, we analyzed the patterns of lymph nodes metastasis (LNM) of patients with peripheral right middle NSCLC <= 3 cm, aiming to provide evidences for surgical choice for early-stage peripheral right middle lobe NSCLC. Methods We retrospectively investigated the clinical and pathological data of patients diagnosed with peripheral right middle lobe NSCLC <= 3 cm between January 2015 and December 2019. The LNM patterns were analyzed by tumor size. Results A total of 60 patients were included for analysis. The tumor size was preoperatively divided as follows: <= 1 cm (13 patients); > 1 cm but <= 2 cm (36 patients); > 2 cm but <= 3 cm (11 patients). Fifty-four patients were categorized as N0 group, 1 patient as N1 group, and 5 patients as N2 group. In the upper zone, 3 patients were found to have LNM. In the subcarinal zone, another 3 patients had LNM. But the lymph nodes of all these patients were negative in the lower zone. In station 10, 1 patient (1.67%) was found to have LNM, while in station 11-13, 2 patients (3.33%) were found to have LNM. Conclusion For the right middle lobe peripheral NSCLC <= 1 cm, sublobar resection with lymph node sampling may be a feasible treatment. For cancers > 1 cm but <= 2 cm, lobectomy with lobe-specific lymph node dissection (especially station 2R and 4R) may be a preferred choice. For tumors > 2 cm but <= 3 cm, lobectomy with systematic lymph node dissection may still be the standard of care.