Primary thyroid non-Hodgkin's lymphoma of Ann Arbor stages IE and IIE: prognostic factors

Abstract

To investigate the prognostic factors of primary non-Hodgkin's thyroid lymphoma. From January 1981 to January 2008, 47 patients with stage IE and IIE pathologically confirmed as suffering from B cell non-Hodgkin's lymphoma and treated in hospital, were retrospectively analyzed. Pathology: diffuse large cell B-cell lymphoma (DLBCL) 28, mucosa-associated lymphoma (MALT) 19. The cancer specific survival (CSS) were calculated using the Kaplan-Meier method and compared by the Log-rank test. Age, sex, symptoms, extrathyroid extension, radiation doses, treatment modality and histological type characteristics were evaluated using the Cox regression analysis. The 5-year CSS rate was 61.8%. The 5-year CSS rate for the patients with primary tumor confined to thyroid and with extrathyroid extension were 86.7% and 50.0% (P=0.012). The 5-year CSS rate for the patients treated with radiation doses below 40 Gy and treated to 40 Gy or more were 30.8% and 79.0% (P=0.002). The 5-year CSS rate for the 18 patients with stage II received single modality therapy and the multimodality therapy were 33.3% and 61.1% (P=0.037). The 5-year CSS rate for patients with DLBCL lymphoma lesions and with MALT were 50.0% and 78.9% (P=0.038). Multivariate analysis by Cox regression showed that extrathyroid extension, radiation doses and histological type were independent prognostic factors. In primary non-Hodgkin's lymphoma of the thyroid, extrathyroid extension, radiation radiation doses and histological type are important prognostic factors. For patients with the stage II received multimodality therapy have a higher CSS than the ones received single-modality therapy.