Prognosis of Resected Non-small Cell Lung Cancer with Ipsilateral Pulmonary Metastasis

Background: Ipsilateral pulmonary metastasis (PM) in the same lobe (T3_Satell) or different lobe (T4_{Ipsi Nod}) constitutes a small proportion of patients with non-small cell lung cancer (NSCLC). In our study, we aimed to determine prognostic factors and to evaluate long-term survival outcomes in the patients who underwent complete resection due to NSCLC.

Methods: Data of 1,502 surgically treated patients with NSCLC from January 2007 to December 2016 were retrospectively reviewed. Fifty (3.3%) patients diagnosed with PM were the basis of the study. Demographic and histopathological characteristics, surgical procedures, and prognostic factors for survival were analyzed, categorizing patients according to the presence of PM in the same lobe or different lobe.

Results: Among the 50 patients, 23 (46%) had PM in the same lobe as the primary tumor and 27 (54%) had PM in different ipsilateral lobes. The mean size of nodules was 11.5 mm. While T3_Satell was detected mostly in squamous cell carcinoma (SCC) (65.2%), T4_{Ipsi Nod} was more common in adenocarcinoma (AC) (70.4%), and the difference was statistically significant (p = 0.022). Survival was significantly better in the SCC-T3_Satell group than the AC-T3_Satell group (64 and 58.3%, respectively; p = 0.043). Although the overall 5-year survival was better in the T3_Satell group, the difference between survival outcomes of both groups was not statistically significant (61.2 and 37.2%, respectively; p = 0.27). In the T3_Satell group, nodule size was found to be a negative prognostic factor in survival (p = 0.042), whereas the number of nodules was found to be a negative prognostic factor in the T4_{Ipsi Nod} group (p = 0.046). In multivariate analysis, advanced age was a poor prognostic factor for PM (p = 0.03).

Conclusion: There was no significant difference in survival between T3_Satell and T4_{Ipsi Nod} patients. Among surgically treated patients due to NSCLC, poor prognostic factors were advanced age for the patients with PM, nodule size and AC for T3_Satell patients, and the number of nodules for T4_{Ipsi Nod} patients.