Operation and Chemotherapy: Prognostic Factors for Lung Cancer With One Synchronous Metastasis

Stage IV non-small cell lung cancer (NSCLC) is considered incurable; however, some patients with only few metastases may benefit from treatment with a curative intent. We aimed to identify the prognostic factors for stage IV NSCLC with synchronous solitary M1.

A database constructed from our weekly multidisciplinary thoracic oncology meetings was retrospectively screened from 1993 to 2012. Consecutive patients with NSCLC stages I to IV were included.

Of the 6,760 patients found, 4,832 patients were studied. Among the 1,592 patients (33%) with stage IV NSCLC, 109 (7%) had a synchronous solitary M1. Metastasis involved the brain in 64% of patients. Median overall survival was significantly longer in synchronous solitary M1 than in other stage IV (18.9 months, interquartile range [IQR]: 9.9 to 34.6 months versus 6.1 months, IQR: 2.3 to 13.7 months], respectively, p < 10^-4). Among patients with synchronous solitary M1, 90 (83%) received a local treatment with curative intent at the primary and metastatic sites. Factors independently associated with survival were age older than 63 years (hazard ratio [HR] 1.63, 95% confidence interval [CI]: 1.01 to 2.63), Performance status of 3 or 4 (HR 7.91, 95% CI: 2.23 to 28.03), use of chemotherapy (HR 0.38, 95% CI: 0.23 to 0.64), and operation conducted at both sites (HR 0.35, 95% CI: 0.19 to 0.65).

Synchronous solitary M1 treated with chemotherapy and operation at both sites resulted in better survival. Survival of NSCLC with synchronous solitary M1 was more similar to stage III than other stage IV NSCLCs. The eighth TNM classification takes this into account by distinguishing between stages M1b and M1c.