Log odds of positive lymph nodes as a novel prognostic indicator in NSCLC staging.

OBJECTIVES: The paper aimed to compare the efficacy of log odds (LODDS) compared to a classification based on the distribution of involved lymph nodes (pN) and lymph node ratio (LNR).

METHODS: Material was collected retrospectively from an online survey-based database of the Polish Lung Cancer Group and included a group of 17,369 patients who received radical surgical treatment (R0) due to lung cancer.

RESULTS: In the whole group the median survival for N0, N1 and N2 was 76.1, 41.7 and 24.2 months, respectively. The median survival for individual LODDS categories (-6,-4], (-4,-3], (-3,-2], (-2,-1], (-1,0], (0,1] and (1,2] was 76.5, 76.3, 71.7, 45.4, 25.0, 19.1 and 17.7 months, respectively. The median survival for LNR in individual categories (0), (0,0.25], (0.25,05], (0.5075] and (0.75,1.0] was 75.6, 40.3, 24.1, 18.8 and 16.4 months, respectively. A multi-variant analysis demonstrated that each LODDS category is an independent prognostic factor: (-4,-3] (HR = 0.982; 95% CI 0.867-1.112; P = 0.775), (-3,-2] (HR = 1.114; 95% CI 0.984-1.262; P = 0.089), (-2,-1] (HR = 1.241; 95% CI 1.080-1.425; P = 0.002), (-1,0] (HR = 1.617; 95% CI 1.385-1.887; P < 0.0001), (0,1] (HR = 1.918; 95% CI 1.579-2.329; P < 0.0001) and (1,2] (HR = 2.016; 95% CI 1.579-2.573; P < 0.0001).

CONCLUSIONS: Based on LODDS it is possible to discriminate patients with regard to lung cancer stage more effectively compared to pN and LNR classification, and it is also a better classification system.