NEW YORK (Reuters Health) – First-line therapy with zidovudine and interferon-alpha improves overall survival in patients with adult T-cell leukemia/lymphoma (ATL), according to the results of a retrospective study. However, patients with leukemic subtypes benefit much more than those with the lymphoma form.
Based on the findings, zidovudine and interferon-alpha “should now be considered the gold standard first-line therapy in leukemic subtypes of ATL,” say the authors of the report appearing in the Journal of Clinical Oncology, published ahead of print on June 28.
Dr. Olivier Hermine at Hopital Necker in Paris, France, and colleagues note that “ATL is highly prevalent in several developing or low-income countries.” They point out that ATL is associated with human lymphotropic virus type 1 (HTLV-1), and since 1995, a number of small studies have shown that antiviral therapy with zidovudine/interferon-alpha is beneficial.
Several questions remain, however, prompting the international team to review and analyze the medical records of 254 patients with ATL, to compare antiviral therapy alone, chemotherapy alone, and chemotherapy followed by maintenance antiviral therapy in different ATL subtypes.
Survival data and first-line treatment information were available for 207 patients; of these, 98 were classified as having acute ATL, 84 had ATL lymphoma, 23 chronic or smoldering ATL, and 2 had unknown subtypes.
When the data were analyzed according to initial therapy, 5-year overall survival rates were 46% for patients who received first-line antiviral therapy compared with 20% for patients who received first-line chemotherapy (p=0.004), and 12% for patients who received first-line chemotherapy followed by antiviral therapy.
Looking at the various subtypes, the researchers found that antiviral therapy in chronic and smoldering ATL resulted in a 100% survival at 5 years. In acute ATL, 82% of patients achieving complete remission with antiviral therapy survived to 5 years.
In ATL lymphoma, however, first-line antiviral therapy alone resulted in a significant survival disadvantage compared with first-line chemotherapy, with 5-year survival rates of 0% and 18%, respectively (p=0.009).
Summing up, Dr. Hermine and associates say the combination of zidovudine and interferon-alpha has changed the natural history of leukemic ATL and significantly improved long-term survival in the subset of patients with the most lethal form of ATL.