Meta-Analysis on the Use of Zidovudine and Interferon-Alfa in Adult T-Cell Leukemia/Lymphoma Showing Improved Survival in the Leukemic Subtypes

PURPOSE: Human T-cell lymphotropic virus type-I-associated adult T-cell leukemia/lymphoma (ATL) is an aggressive, chemotherapy-resistant malignancy. Multiple small studies using zidovudine (AZT) and interferon-alfa (IFN-α) have shown response in patients with ATL. However, the impact of this innovative antiviral treatment strategy on long-term survival remains undetermined. PATIENTS AND METHODS: We report a meta-analysis of antiviral therapy of ATL. Medical records of 254 patients with ATL who were treated in the United States, the United Kingdom, Martinique, and continental France were individually reviewed. RESULTS: According to Shimoyama classification, there were 116 patients with acute ATL, 18 patients with chronic ATL, 11 patients with smoldering ATL, and 100 patients with ATL lymphoma. In 231 patients with available survival data, first-line therapy was recorded in 207 patients. Five-year overall survival rates were 46% for 75 patients who received first-line antiviral therapy (P = .004), 20% for 77 patients who received first-line chemotherapy, and 12% for 55 patients who received first-line chemotherapy followed by antiviral therapy. Patients with acute, chronic, and smoldering ATL significantly benefited from first-line antiviral therapy, whereas patients with ATL lymphoma experienced a better outcome with chemotherapy. In acute ATL, achievement of complete remission with antiviral therapy resulted in 82% 5-year survival. Antiviral therapy in chronic and smoldering ATL resulted in 100% 5-year survival. Multivariate analysis confirmed that first-line antiviral therapy significantly improves overall survival of patients with ATL (hazard ratio, 0.47; 95% CI, 0.27 to 0.83; P = .021). CONCLUSION: These results confirm the high efficacy of AZT and IFN, which should now be considered the gold standard first-line therapy in leukemic subtypes of ATL.