Interferon in multiple myeloma--summary of treatment results and clinical implications.

Even though interferon (IFN) has been used in myeloma treatment for more than two decades, its efficacy is still controversial. Meta-analysis of randomized trials is based either on individual patient data or on published data. We performed meta-analyses on published and reported data using, in addition to the standard method, three independent methods of evaluating Kaplan-Meier curves. Thirty randomized trials on IFN induction or maintenance treatment were meta-analyzed. Combined IFN-chemotherapy induction treatment resulted in significant increases of repsonse rates (6.6%), as well as median relapse-free (4.8 months) and overall survival (3.1 months). IFN maintenance treatment prolonged median relapse-free survival by 4.4 months, median overall survival by 7.9 months. Drug costs of IFN per 1-year survival gain were US$ 42,236.19 for induction therapy and US$ 18,114.95 for maintenance treatment. To conclude, our results a are in accordance with those obtained from individual patient data by the Myeloma Trialists' Collaborative Group. Because of the consistent, though limited, improved trial outcomes, IFN treatment should be suggested to all myeloma patients who might benefit from it.