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

Background: The reports of clinicaloutcomes of patients treated with chemoradiotherapy for primary thyroidnon-Hodgkin’s lymphoma are rare. We report our results of chemoradiotherapy forprimary thyroid non-Hodgkin’s lymphoma. Materials and Methods: The subjects were 67 patients with thyroidnon-Hodgkin’s lymphoma among 269 patients with malignant lymphoma who receivedradiotherapy 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, MALTin 9, diffuse type in 52, follicular type in 5, and diffuse and follicular typein 1. CHOP chemotherapy regimen for malignant lymphoma patients was as follows.Intravenous drip infusion of cyclophosphamide 750 mg/m2, (drip)infusion of doxorubicin 50 mg/m2, and intravenous injection ofvincristine 1.4 mg/m2 were administered on day 1, followed by 5consecutive days of oral prednisolone 100 mg/m2. This regimen wasrepeated every 3 weeks (21 days) in 6 to 8 courses. Modified CHOP chemotherapyregimen was as follows. Intravenous dripinfusion of cyclophosphamide 600 mg/m2, intravenous (drip) infusionof doxorubicin 40 mg/m2, intravenous infusion of vindesine 3mg/m2, and intravenous drip infusion of prednisolone 60 mg/body wereadministered on day 1, and intravenous prednisolone was changed to oral prednisolonewith the dose tapered gradually. After completing one course of this regimen,two courses of radiotherapy (a total of 36 Gy) were performed, followed by 6courses 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-yearsurvival rate was over 80%. Although there were no significant differences inthe results of chemoradiotherapy among different histologic types of thyroidmalignant lymphoma, the survival rate was 100% for MALT type, as compared withpoor results for diffuse large type or diffuse mixed type. The analysis of theresults of chemoradiotherapy according to the stage of malignant thyroidlymphomas revealed that therapeutic results were significantly better in stageI than in stage II. Conclusion: The CHOP chemoradiotherapy regimen and modified CHOP chemoradiotherapyregimen were excellent for primary thyroid non-Hodgkin’s lymphoma.