Purpose: The aim of this study was to identify risk factors for recurrence in non-small cell lung cancer (NSCLC) patients with lymph node metastases after surgical resection.
Methods: We reviewed 66 consecutive patients with surgically resected NSCLC who had pathologically proven positive lymph nodes (pN1 or pN2). All patients underwent a preoperative 2-[(18)F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) evaluation. We analyzed the recurrence-free survival (RFS) and recurrence-free proportion (RFP) according to the clinicopathological factors.
Results: A total of 27 patients were pathologically N1 and 39 were N2. The 5-year overall survival rate and the RFS rate were 47.2 and 27.7 %, respectively. The cut-off values for the SUVmax of the tumor and the lymph node ratio (LNR) were determined to be 6.5 and 0.12, respectively, using a receiver operating characteristics curve analysis. Both univariate and multivariate analyses revealed three significant independent factors for RFS: namely, the SUVmax of the tumor, the LNR, and the use of adjuvant chemotherapy. Only the SUVmax was an independent significant predictor of the RFP.
Conclusions: Both the SUVmax and the LNR can serve as prognostic factors for patients with pN + NSCLC. Our study suggests that the LNR could be a stronger prognostic factor than the N classification of the TNM system and the SUVmax may predict recurrence in node-positive NSCLC patients.
Keywords: FDG-PET; Lymph node metastasis; Lymph node ratio (LNR); Non-small cell lung cancer; SUVmax.