J.Jpn. Surg. Soc.. 127(1): 11-18, 2026

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Feature topic

CURRENT STATUS AND FUTURE PERSPECTIVES OF TREATMENT STRATEGIES FOR SMALL-SIZED LUNG CANCER

In Japan, the number of surgical procedures for primary lung cancer has continued to rise, exceeding 48,000 cases in 2023. Sublobar resection now accounts for 39% of procedures and has become an important treatment option for small-sized lung cancers. With 5-year survival rates for stage IA disease exceeding 90%, the 2022 Japanese Lung Cancer Guidelines for the first time strongly recommended sublobar resection in selected cases. Evidence supporting this approach has evolved following the negative results of the 1995 LCSG trial, primarily through a series of JCOG/WJOG studies. JCOG0802/WJOG4607L demonstrated that segmentectomy was not only noninferior but also superior to lobectomy in overall survival for small invasive tumor patients, while CALGB140503 confirmed the noninferiority of sublobar resection, establishing its global validity. For noninvasive tumors, JCOG0804/WJOG4507L (CTR ≤0.25) and JCOG1211 (≤3 cm, CTR ≤0.5) reported excellent 5-year disease-free survival rates of 99.7% and 98.0%, respectively, further supporting sublobar resection as a standard option. These findings have firmly positioned sublobar resection as a standard treatment, although unresolved issues remain, including predictors of local recurrence, surgical margins, and lymph node dissection strategies. Continued innovation toward “sublobar resection ver. 2.0” is the next mission for thoracic surgeons in Japan.

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