RT-DeVIC Therapy Is Effective for Localized NK/T Cell Lymphoma Patiens

BACKGROUNDS: Extranodal natural killer (NK) /T cell lymphoma, nasal type is much common in East Asia than in Western countries. CHOP therapy is not effective for NK/T cell lymphoma because of the drug resistance induced by P glycoprotein. Yamaguchi et al reported the effectiveness of concurrent radiotherapy and DeVIC (RT-DeVIC) therapy for localized nasal NK/T cell lymphoma. Nowadays, RT-DeVIC therapy is recognized as a standard treatment. So far, we have limited information about this treatment because NK/T cell lymphoma is rare phenotype.

PATIENTS AND METHODS: We reviewed retrospectively the patients with localized NK/T cell lymphoma treated with RT-DeVIC therapy. Radiation therapy was administered for a total dose of 50 Gy. Concurrently, chemotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin (DeVIC) was performed up to 3 cycles. The primary objectives of this analysis were to evaluate the response rates and progression free survival (PFS) and overall survival (OS). RESULTS: A total of 20 patients who diagnosed as nasal NK/T cell lymphoma between April 2007 and October 2012 were analyzed. Sixteen patients were stage 1E and 4 were Stage 2E. As the NK/T cell lymphoma prognostic index, 6 patients were group 1, 10 were group 2, 3 were group 3, and 1 was group 4. Seventeen patients completed 3 cycles of DeVIC therapy and 19 patients completed planned radiation therapy. Overall response rate (ORR) was 75% and CR rate was 70% in the entire patients. Local control was 90%. Half of the patients who reached CR showed long time survival without disease progression. On the other hand, 7 of 14 patients relapsed after CR, and all 5 patients experienced systemic failure. The sites of relapse were paranasal sinuses (n=2), skin (n=3), brain (n=1), testis (n=1). Among them, one patient reached 2^nd CR. However, 5 patients were not eligible for salvage chemotherapy, because lymphoma progressed rapidly and their general condition became worse. Six patients did not reach CR after RT-DeVIC therapy. Five of them experienced systemic relapse and median survival of them was only 8 months. The median follow up time was 17.6 months (range 2 – 77.9 months). Median overall survival was not reached and median progression free survival was 14.6 months. Risk factors predicted of OS or PFS were not clear. All entire patients experienced grade 3 or 4 neutropenia. Mucositis was common non-hematological toxicity and it was the major cause of grade 3 or 4 appetite loss. Only one patient discontinued RT-DeVIC due to grade 3 mucositis, grade 3 dermatitis and septic shock.

CONCLUSION: We reviewed treatment outcomes of 20 cases of RT-DeVIC therapy. In this analysis, the majority of relapsed or refractory cases showed systemic disease and the prognosis of these patients were poor. However, RT-DeVIC therapy showed excellent local control and response rates which were similar to the prior study. The effectiveness of RT-DeVIC therapy for patients with NK/T cell lymphoma was reconfirmed.