Interferon alpha not only has its own antitumor action but also modulates the immune response, including the activity of white blood cells that might be capable of attacking tumors. Results of several studies have suggested that those whose tumors show white cells infiltrating them have the best prognosis, but this has not been seen in other studies. A possible reason for this discrepancy is that it may be only certain types of white cells that are critical for an anticancer effect. Twenty patients with regional metastases underwent surgery after only 1-3 weeks of interferon alpha because of the curative potential of resection. It is not surprising to find it also playing a role in antitumor action as suggested by this study.
Immune function seems to play a prominent role in development and dissemination of melanoma.