Postoperative Prognosis in Patients With Non–Small Cell Lung Cancer With Synchronous Ipsilateral Intrapulmonary Metastasis

Background. Non–small cell lung cancer with intrapulmonary metastasis (PM) was recently reclassified according to the revision of the TNM classification. To determine whether the new staging system is appropriate, we analyzed the postoperative prognosis of patients with synchronously detected and resected PM lesions. Methods. Of 509 patients with non–small cell lung cancer who underwent surgical resection, 42 patients were revealed to have synchronous and ipsilateral PM. Their survival was compared with that of matched stage groups (without PM) by Kaplan-Meier test and log rank test. Results. Two patients who were classified as stage I survived 40 and 30 months after operation, respectively. One patient was determined to be stage II, and survived 100 months postoperatively. Thirty-eight patients were classified as stage IIIA/IIIB (19 each) (90.5% of all cases with PM). There was no significant difference between 3- and 5-year survival rates of the PM stage IIIA group (34.2% and 34.2%) and those of the other IIIA (144 patients; 37.9% and 31.6%). Survival rates of such stage IIIA subgroups as PM, T3 and N2, were comparable. No significant differences were observed between the 3- and 5-year survival rates of the PM stage IIIB (16.6/16.6%) and those of the other stage IIIB (45 cases; 11.7% and 0.0%). The survival rates of such stage IIIB subgroups as PM, T4 and N3 were also similar. Conclusions. The new staging system for patients with synchronous resectable PM appears to be reasonable regarding survival. Most cases of PM are categorized as locally advanced disease; however, stage IIIA/IIIB cases have become a more heterogeneous population.