Phase 2 Study of First-line Intensity Modulated Radiation Therapy Followed by Gemcitabine, Dexamethasone, and...

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).

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.

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.

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