Tumor-infiltrating lymphocyte grade in primary melanomas is independently associated with melanoma-specific survival in the population-based genes, environment and melanoma study
Thomas, NE and Busam, KJ and From, L and Kricker, A and Armstrong, BK and Anton-Culver, H and Gruber, SB and Gallagher, RP and Zanetti, R and Rosso, S and Dwyer, T and Venn, A and Kanetsky, PA and Groben, PA and Hao, H and Orlow, I and Reiner, AS and Luo, L and Paine, S and Ollila, DW and Wilcox, H and Begg, CB and Berwick, M, Tumor-infiltrating lymphocyte grade in primary melanomas is independently associated with melanoma-specific survival in the population-based genes, environment and melanoma study, Journal of Clinical Oncology, 31, (33) pp. 4252-4259. ISSN 0732-183X (2013) [Refereed Article]
copyright 2013 American Society of Clinical Oncology
Although most hospital-based studies suggest more favorable survival with tumor-infiltrating lymphocytes (TILs) present in primary melanomas, it is uncertain whether TILs provide prognostic information beyond existing melanoma staging definitions. We addressed the issue in an international population-based study of patients with single and multiple primary melanomas.
PATIENTS AND METHODS:
On the basis of the Genes, Environment and Melanoma (GEM) study, we conducted follow-up of 2,845 patients diagnosed from 1998 to 2003 with 3,330 invasive primary melanomas centrally reviewed for TIL grade (absent, nonbrisk, or brisk). The odds of TIL grades associated with clinicopathologic features and survival by TIL grade were examined.
Independent predictors (P < .05) for nonbrisk TIL grade were site, histologic subtype, and Breslow thickness, and for brisk TIL grade, they were age, site, Breslow thickness, and radial growth phase. Nonbrisk and brisk TIL grades were each associated with lower American Joint Committee on Cancer (AJCC) tumor stage compared with TIL absence (Ptrend < .001). Death as a result of melanoma was 30% less with nonbrisk TIL grade (hazard ratio [HR], 0.7; 95% CI, 0.5 to 1.0) and 50% less with brisk TIL grade (HR, 0.5; 95% CI, 0.3 to 0.9) relative to TIL absence, adjusted for age, sex, site, and AJCC tumor stage.
At the population level, higher TIL grade of primary melanoma is associated with a lower risk of death as a result of melanoma independently of tumor characteristics currently used for AJCC tumor stage. We conclude that TIL grade deserves further prospective investigation to determine whether it should be included in future AJCC staging revisions.