Clinical Outcomes of 67 Patients Treated with Chemoradiotherapy for Primary Thyroid Non-Hodgkin’s Lymphoma in Osaka Medical College

Abstract

Background: The reports of clinical outcomes of patients treated with chemoradiotherapy for primary thyroid non-Hodgkin’s lymphoma are rare. We report our results of chemoradiotherapy for primary thyroid non-Hodgkin’s lymphoma. Materials and M ethods: The subjects were 67 patients with thyroid non-Hodgkin’s lymphoma among 269 patients with malignant lymphoma who received radiotherapy in our hospital during a period between May 1990 and June 2005. The patients included 16 men and 51 women, with a mean age of 66.2 ± 10.7 years (30 - 84 years). The disease stage was stage I in 42 patients, stage II in 24, and unclear in 1. The histologic type was B-cell lymphoma in 66 patients, MALT in 9, diffuse type in 52, follicular type in 5, and diffuse and follicular type in 1. CHOP chemotherapy regimen for malignant lymphoma patients was as follows. Intravenous drip infusion of cyclophosphamide 750 mg/m 2 , (drip) infusion of doxorubicin 50 mg/m 2 , and intravenous injection of vincristine 1.4 mg/m 2 were administered on day 1, followed by 5 consecutive days of oral prednisolone 100 mg/m 2 . This regimen was repeated every 3 weeks (21 days) in 6 to 8 courses. Modified CHOP chemotherapy regimen was as follows. Intravenous drip infusion of cyclophosphamide 600 mg/m 2 , intravenous (drip) infusion of doxorubicin 40 mg/m 2 , intravenous infusion of vindesine 3 mg/m 2 , and intravenous drip infusion of prednisolone 60 mg/body were administered on day 1, and intravenous prednisolone was changed to oral prednisolone with the dose tapered gradually. After completing one course of this regimen, two courses of radiotherapy (a total of 36 Gy) were performed, followed by 6 courses of the chemotherapy regimen at lower doses (80% of the initial doses) repeated once a month. Results: Results of chemoradiotherapy in all patients were excellent. The 15-year survival rate was over 80%. Although there were no significant differences in the results of chemoradiotherapy among different histologic types of thyroid malignant lymphoma, the survival rate was 100% for MALT type, as compared with poor results for diffuse large type or diffuse mixed type. The analysis of the results of chemoradiotherapy according to the stage of malignant thyroid lymphomas revealed that therapeutic results were significantly better in stage I than in stage II. Conclusion: The CHOP chemoradiotherapy regimen and modified CHOP chemoradiotherapy regimen were excellent for primary thyroid non-Hodgkin’s lymphoma.