Inflammation and migration in primary melanoma and corresponding metastasis
Department of Plastic and Breast Surgery, Louise Bønnelykke
Inflammation is a hallmark of cancer and reactivation of important developmental and migratory cell properties of the melanocyte (spindle cell configuration and loss of e-cadherin) may be an essential link between inflammation and poor survival in patients with melanoma. How the metastatic inflammatory microenvironment is characterised is yet to be elucidated, but may be of great importance when treating patients with metastatic melanoma with BRAF inhibitors and immunotherapy. In the metastases, we detected massive macrophage infiltration and lower expression of e-cadherin on the tumour cells. Infiltration of macrophages was associated with spindle cell characteristics of the tumour cells in the metastases. Neutrophils infiltrated to a higher extent in the metastases (when adjusted for ulcerated status), which was associated with poor melanoma-specific survival. In addition, we found that BRAFV600E tumours exhibited denser macrophage and dendritic cell infiltration.
These results suggest an essential role for innate immune cells in the metastatic process. Also, our results highlight the importance of recognizing the role of innate immune cells as they may be used to improve the effects of immunotherapy and BRAFV600E targeted therapy for patients with melanoma.
