Long-term outcomes of upfront concurrent chemoradiotherapy followed by P-GDP regimen in newly diagnosed early stage extranodal nasal-type NK/T cell lymphoma: A prospective single-center phase II study

The optimal treatment strategy of newly diagnosed stage I/II, extranodal nasal-type natural killer/T cell lymphoma (NKTCL) remains unclear. This prospective phase II trial was conducted to explore the short-term and the long-term efficacy and safety of upfront concurrent chemoradiotherapy (CCRT) followed by pegaspargase, gemcitabine, dexamethasone, cisplatin (P-GDP) regimen in patients newly diagnosed with early stage NKTCL. Thirty patients newly diagnosed with stage I/II NKTCL were enrolled from January 2013 to December 2016, and treated as the following strategy: upfront CCRT with cisplatin weekly (25 mg/m(2)) for 5 weeks, followed by 3 cycles of P-GDP regimen chemotherapy (pegaspargase 2500IU/m(2) capped at 3750IU, intramuscular on day 4, gemcitabine 850 mg/m(2) intravenous on days 1 and 8; dexamethasone 40 mg/day intravenous on days 1 to 4; and cisplatin 20 mg/m(2) intravenous on days 1–3) 3 weeks after the completion of CCRT. The objective response rate (ORR) and the complete response (CR) rate were the primary endpoints, and the secondary endpoints were the overall survival (OS), progression-free survival (PFS), and the adverse event (AE). The median follow-up period was 51.5 months (range, 5–78months). The ORR was 93.3% (28/30) and all these 28 patients attained CR at the end of the treatment. Two patients suffered from lymphoma associated hemophagocytic syndrome (LAHS) during the period of consolidation chemotherapy and died within 2 months. The 5-year OS was 93.3%, and the 5-year PFS was 89.4%Mucositis was the most common grades 3/4 nonhematologic AEs (10%, 3/30) of CCRT. During the P-GDP chemotherapy, vomiting (6.7%, 2/30), neutropenia (43.3%, 13/30) and thrombocytopenia (23.3%, 7/30) were the major grades 3/4 toxicities during chemotherapy. No treatment-related deaths occurred. The upfront CCRT followed by P-GDP regimen chemotherapy is an effective and well-tolerated first-line treatment strategy for patients diagnosed with early stage NKTCL. Further investigation of larger sample size is warranted.