The role of interleukin-8 in the initiation and progression of human cutaneous melanoma

Background: The expression of Interleukin-8 (IL-8) by human melanoma cells correlates with their metastatic potential in vitro and in nude mice. The role of IL-8 in human patients is not yet clear. The purpose of the present study was to search for a possible correlation between IL-8 in patients' melanoma specimens and the clinical course of the disease. Patients and Methods: All patients operated on for malignant melanoma (MM) at our center between 1985 and 1993 were screened for the study. Only those with retrievable pathological and clinical material were included. IL-8 tumor levels were tested by immunohistochemistry. Results: Seventy-four patients were eligible for inclusion in the study. In 49, the primary tumor was analyzed and in 25 a metastasis. IL-8 was expressed in 91% of the primary lesions, 70% of the lymph node metastasis and 70% in local recurrence or in-transit metastases. There was no correlation between level of expression and outcome. Comparing IL-8 expression in primary and secondary lesions of the same patient showed a trend towards better survival for those who had down-expression of IL-8. Conclusion: IL-8 is over-expressed in cutaneous MM. Although no direct correlation was found in the present study between IL-8 expression and survival, it would appear that IL-8 plays a major role in melanoma development.