Rituximab-including combined modality treatment for primary thyroid lymphoma: an effective regimen for elderly patients.

Background: Primary thyroid lymphoma (PTL) develops mostly in middle-aged and older females. However, the optimal treatment for elderly patients with diffuse large B-cell lymphoma (DLBCL), which accounts for most PTL cases, is unclear. Rituximab is a promising drug that, in combination with traditional combination therapy, has demonstrated an increased antitumor effect without a substantial increase in toxicity. In this study, treatment outcomes of elderly patients with thyroid DLBCL who underwent rituximab-including combination therapy were analyzed.

Method: Between January 2005 and December 2011, 43 patients 60 years of age or older (median 71 years, range 60-80 years) were diagnosed as having stage IE (n=12) or stage IIE (n=31) DLBCL, and three courses of R-CHOP therapy (rituximab 375 mg/m2, cyclophosphamide 750 mg/m2, adriamycin 40 mg/m2, vincristine 1.4 mg/m2, and prednisolone 100 mg/body) and involved field irradiation were planned. Treatment outcomes of these patients were retrospectively reviewed.

Results: Two patients terminated the treatment because of interstitial pneumonia during R-CHOP therapy. Only one patient showed treatment resistance and the regimen was changed; 42 patients (98%) responded to the treatment. Five-year overall survival and event-free survival were 87% (95% confidence interval [95% CI], 64-96%) and 74% (95% CI, 50-89%), respectively.

Conclusion: The results of the present study indicate that rituximab-including combination therapy was effective for elderly patients with thyroid DLBCL. A multicenter, long-term observational study is needed to confirm this, and additional refinement of the treatment protocol is required to optimize the antitumor effect.