Function-preserving radical surgery for early-stage non-small cell lung cancer: A review of limited resection approaches.

Radical lobectomy, proposed as a curative treatment for lung cancer in 1960, has long been regarded as the standard surgical approach. The findings of two phase III randomized controlled trials comparing limited resection versus lobectomy for non-small cell lung cancer (NSCLC) ≤2 cm have challenged the long-standing evidence supporting lobectomy as the universal surgical option for all patients with lung cancer. The Japanese clinical oncology group (JCOG) and West Japan Oncology Group (WJOG) (JCOG0802/WJOG4607L) demonstrated both the non-inferiority and superiority of segmentectomy, while the Cancer and Leukemia Group B trial (CALGB140503) conducted by the Alliance for Clinical Trials in Oncology in North America, confirmed the non-inferiority of limited resection, including wedge resection for NSCLC measuring ≤2 cm. As both trials demonstrated non-inferiority of limited resection in NSCLC ≤2 cm, their results are often summarized together. However, patient background, radiological findings, prognosis, and extent of resection differ significantly between the two trials and should be interpreted with caution. Previous trials have demonstrated that preserving lung parenchyma helps maintain pulmonary function and improves patient prognosis by enabling appropriate management of subsequent malignancy or other diseases. Limited resection, including segmentectomy, is currently the standard of care for early-stage NSCLC. The JCOG and WJOG are conducting trials to determine whether the indications for limited resection can be expanded to include patients with NSCLC >2 cm or those with stage I NSCLC. This review article outlines the results of previous trials, provides an overview of ongoing trials, and discusses prospects for limited resection.