Comparison of five different scoring methods in the evaluation of inflammatory infiltration (tumor-infiltrating lymphocytes) in superficial spreading and nodular melanoma

The objective of our study was to compare the five different scoring methods of tumor-infiltrating lymphocytes (TILs) assessment in a group of 213 cases of superficial spreading and nodular melanoma. The scoring methods include (a) Clark scoring; (b) Melanoma Institute Australia system; (c) scoring system used in the study of Saldanha et al.; (d) scoring system used in the TCGA study and modified by Park et al.; and (e) the system recently proposed by the " International Immuno-Oncology Biomarker Working Group" for TILs scoring in all solid tumors. Prediction of survival with three main outcomes-disease-specific-free survival, local recurrence-free survival, and distant metastasis-free survival-was evaluated. The prognostic value of TILs showed statistical significance in univariate analysis regarding all three of the outcomes only for three of the five evaluated methods; the Clark scoring, the Melanoma Institute Australia system, and the system proposed by the " International Immuno-Oncology Biomarker Working Group". However, in multivariate analysis with covariants including Breslow thickness, type of melanoma, location, sex, and age, we did not find TILs to be an independent prognostic factor.