B04 - Primary cutaneous melanoma in elderly patients: analyses and considerations from a retrospective observational study

Abstract

Background: Cutaneous melanoma is an immunogenic cancer and the interaction of the aging immune system with melanoma could have an important effect on the biologic behaviour of this disease. Compared with younger patients (pts), primary cutaneous melanoma observed in elderly pts tend to be thicker, more often ulcerated and usually exhibit an increased mitotic activity. Tumor infiltrating lymphocytes (TILs) is a potential marker of effective host immunological response to the tumor. The aim of the study is to evaluate pathological features, including TILs, and lymph node status of primary cutaneous melanoma in elderly pts. Patients and methods: The study analyzed 96 consecutive cases of early melanoma occurred in pts aged 65 years or older at the time of diagnosis. The series included cases observed between Jan 2010 and Mar 2014 at the Department of Oncology of Udine. We tested the association of TILs and other pathological data with disease-free survival (DFS). Results: Among 96 elderly pts, 39 (41%) were female and 57 (59%) were male pts. The median age was 74 years (65-89 years). Concerning pathological characteristics of primary cutaneous melanoma, median thickness was 2 mm, the ulceration was present in 39 (42%) melanomas and number of mitosis was lower than 1 in 16 (17%). TILs grade, classified as Brisk, No Brisk, TILs Absent were found in 12 (13%), 47 (49%) and 37 (38%) cases, respectively. Overall, 79 pts (82%) underwent lymphatic mapping and sentinel lymph node (SLN) biopsy; among them, 63 pts (80%) presented negative SLN. TILs grade was not associated to SLN status. Only 6 pts underwent a lymph node dissection for clinical evidence of regional lymph node involvement at diagnosis. With a median follow-up of 36 months, 26 pts (27%) developed recurrence. No visceral recurrence (skin and nodes) occurred in 19 pts (20%), whereas 7 patients (8%) had visceral recurrence. DFS was not associated to TILs grade. However, primary melanomas with no TILs were associated with a trend of worse DFS, the median DFS was 50.8 months versus not reached (p = 0.089). Conclusions: TILs grade was not associated with other pathological features and lymph nodes status in elderly pts with early melanoma. A considerable number of elderly pts underwent SLN biopsy, an important staging step for clinical decision making process. DFS seems not to be associated with TILs grade, although pts with a diagnosis of early melanoma with absence of TILS tended to present worse DFS.