THYROID LYMPHOMA - THE CASE FOR COMBINED-MODALITY THERAPY

Background. Radiation therapy with or without surgery is generally con sidered standard treatment for lymphoma of the thyroid. Because of the small number of cases, the role of chemotherapy or combined modality treatment is difficult to determine. Methods. The published literature was analyzed, supplemented by a series from Yale, for the incidence o f local and distant relapse after radiation therapy, chemotherapy, or combined modality treatment for Stage I-II thyroid lymphoma. Patients with advanced disease or in whom radiation was probably inadequate wer e excluded. Only patients receiving an anthracyline-based regimen were considered in the group with chemotherapy. Patients receiving single agents or non-anthracycline-based regimens were excluded from analysis or, if they also received radiation, were included in the group that received radiation only. Results. Including a series from Yale, a tota l of 211 patients with Stage IE and IIE thyroid lymphoma were identifi ed. Distant and overall relapse rate were significantly lower in the g roup that received combined modality treatment. Local relapse was also less, but the difference was not statistically significant. In a smal l number of patients with disease confined to the neck, the results wi th radiation were similar to combined modality treatment if the medias tinum was included in the treatment port. Conclusion. Although mucosa- associated lymphoma tissue lymphomas are thought to have a low distant recurrence rate and are therefore often treated with local therapy al one, a review of the published literature suggests that 30% of thyroid lymphomas with clinically localized disease will have a distant relap se. The addition of chemotherapy to radiation significantly lowered di stant and overall recurrence.