Background: More than half of melanoma patients rendered disease free by lymph node dissection will experience disease recurrence. We hypothesized that serum levels of melanoma-inhibiting activity (MIA) protein might be useful to stratify risk and identify subclinical recurrence in patients undergoing adjuvant immunotherapy. We examined MIA levels in the serum of stage III patients treated after surgery with a therapeutic cancer vaccine.
Methods: Three cohorts of 25 patients were randomly selected from our melanoma database on the basis of time to death (group 1, <1 year; group 2, 1-5 years; group 3, >5 years.) Prospectively collected serum samples were assayed in a blinded fashion for MIA by enzyme-linked immunosorbent assay.
Results: MIA was increased at any time in 19 (76%) of 25, 4 (16%) of 25, and 1 (4%) of 25 patients in groups 1, 2, and 3, respectively. The median survival was 11 months for the 25 patients with increased MIA and >75 months for the 50 patients with normal MIA. MIA increased above normal a median of 1 month (mean, 75 days) before clinical recurrence. All patients with increased MIA after 2 months of treatment subsequently died of melanoma. One patient in whom initially increased levels decreased to normal within 2 months is disease free.
Conclusions: Serum MIA levels provide important prognostic information early in the course of stage III melanoma and often detect melanoma recurrences before clinical evidence of disease.