The Lung Cancer Surgical Study Group of the Japan Clinical Oncology Group: outstanding contribution and entering a new phase.

The Lung Cancer Surgical Study Group (LCSSG) of the Japan Clinical Oncology Group (JCOG) was organized in 1986 and initially included 26 collaborative institutions, which has increased to 52 institutions currently. JCOG-LCSSG includes thoracic surgeons, medical oncologists, pathologists, and radiotherapists. In the early period, the JCOG-LCSSG mainly focused on combined modality therapies for lung cancer. Since the 2000s, the JCOG-LCSSG has investigated adequate modes of surgical resection for small-sized and peripheral non-small cell lung cancer and based on the radiological findings of whole tumor size and ground-glass opacity. Trials, such as JCOG0802, JCOG0804, and JCOG1211, have shown the appropriateness of sublobar resection, which has significantly influenced routine clinical practice. With the introduction of targeted therapy and immunotherapy, treatment strategies for lung cancer have changed significantly. Additionally, with the increasing aging population and medical costs, tailored medicine is strongly recommended to address medical issues. To ensure comprehensive treatment, strategies, including surgical and nonsurgical approaches, should be developed. Currently, the JCOG-LCSSG has conducted numerous clinical trials to adjust the diversity of lung cancer treatment strategies. This review highlights recent advancements in the surgical field, current status, and future direction of the JCOG-LCSSG.