Melanogenesis affects overall and disease-free survival in patients with stage III and IV melanoma

Abstract

Because melanogenesis can affect immune responses to and chemotherapy and radiotherapy for melanoma, we analyzed overall survival and disease-free survival times in melanoma patients in relation to the degree of tumor pigmentation. Clinicopathologic data were obtained from the Oncology Centre, Prof Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz, Poland. The overall survival and disease-free survival analyses were performed using the log-rank test, whereas differences between mean/median overall survival and disease-free survival (days) were analyzed using the Student t test. In patients with metastatic disease, those with melanotic melanomas exhibited significantly shorter disease-free survival and overall survival than those with amelanotic lesions. Similarly, melanin-producing lymph node metastases were linked to shorter overall survival and disease-free survival, which was confirmed by a significantly longer mean/median disease-free survival for amelanotic versus melanotic metastases. Melanogenesis shortens overall survival and disease-free survival in patients with metastatic melanoma. Inhibition of melanogenesis appears a rational adjuvant approach to the therapy of metastatic melanoma.

Keywords: Melanin; Melanogenesis; Melanoma; Metastatic melanoma; Survival.

Fig. 1

Representative sections of amelanotic (A), moderately (B, two cases separated by dashed line), and strongly (C, two cases separated by dashed line) pigmented melanomas. Scale bar, 50 µm.

Fig. 2

Relationship between melanin content and disease-free and overall survival in patients with melanomas. A and B, DFS (A) and OS (B) curves in all melanoma patients (localized and metastatic disease) were not affected by melanogenesis. C and D, Melanogenesis in primary metastasizing melanomas (C) and lymph node metastases (D) correlated with significantly shorter OS. E, The presence of melanin in lymph node metastases also significant correlates with shorter DFS. F, When stratified into groups with decreased or increased melanin content in metastases relative to primary melanomas, there was a significant correlation with DFS.