Phase 2 Study of First-line Intensity Modulated Radiation Therapy Followed by Gemcitabine, Dexamethasone, and Cisplatin for High-Risk, Early Stage Extranodal Nasal-Type NK/T-Cell Lymphoma: The GREEN Study.

PURPOSE: To investigate the efficacy and toxicity profile of sequential intensity modulated radiation therapy (IMRT) followed by gemcitabine, dexamethasone, and cisplatin (GDP) on previously untreated high-risk, early stage upper aerodigestive tract natural killer/T-cell lymphoma (UADT-NKTCL).

METHODS AND MATERIALS: A phase 2 study was designed, and 40 high-risk patients with stage I(E)/II(E) UADT-NKTCL were enrolled between June 2010 and June 2014. High-risk patients were defined as those with at least 1 predefined risk factor: age >60 years, elevated serum lactate dehydrogenase, regional lymph node involvement, B symptoms, and primary tumor invasion. Patients received extended involved-site IMRT and GDP chemotherapy. The primary endpoint was the 2-year progression-free survival rate. Secondary endpoints were the 2-year overall survival rate, overall response rate, and toxicity.

RESULTS: Median follow-up time was 60.1 months. The overall response rate and complete remission rate were 97.5% and 95.0%, respectively. The 2- and 5-year progression-free survival rates were 84.7% and 79.4%, and the corresponding overall survival rates were 89.9% and 82.1%, respectively. The most frequent radiation-induced toxicities were mild mucositis and skin reaction. Grade 3/4 neutropenia (12 of 40 patients), thrombocytopenia (7 of 40), and anemia (2 of 40) were observed during chemotherapy.

CONCLUSIONS: First-line IMRT followed by GDP represents an effective and well-tolerated protocol for high-risk, early stage UADT-NKTCL.