Effectiveness of gemcitabine, pegaspargase, cisplatin, and dexamethasone (DDGP) combination chemotherapy in the treatment of relapsed/refractory extranodal NK/T cell lymphoma: a retrospective study of 17 patients.

The prognosis of extranodal nature killer (NK)/T cell lymphoma (ENKL) is dismal because of its aggressive course and multidrug resistance. Currently, for patients with relapsed/refractory ENKL, L-asparaginase-based regimens such as L-asparaginase, ifosfamide, methotrexate, etoposide, and dexamethasone (SMILE) or L-asparaginase, methotrexate, and dexamethasone (AspaMetDex) are recommended. We retrospectively investigated the efficacy and safety of gemcitabine, pegaspargase, cisplatin, and dexamethasone (DDGP) combination chemotherapy in the treatment of 17 relapsed/refractory ENKL patients. Clinical data from these patients were collected and analyzed. The primary end point was overall response rate (ORR). All patients were subjected to 2 to 6 cycles of DDGP chemotherapy, and the median number of cycles of DDGP regimen administrated was four. The ORR was 88.2 % (15/17), with nine patients (52.9 %) achieved complete response (CR) and six patients (35.3 %) achieved partial response (PR). The median follow-up time was 17 months (range 2-28 months). The 1-year overall survival (OS) rate and 1-year progression-free survival (PFS) were 82.4 and 64.7 %, respectively. For those CR responders, the median PFS was 17 months. Grade 3/4 neutropenia occurred in nine patients (52.9 %) and grade 3/4 thrombocytopenia occurred in six patients (35.3 %). DDGP combination chemotherapy produces favorable outcomes in relapsed/refractory ENKL, and more attention should be paid to treatment-related myelosuppression. Further prospective trials are expected to define the efficacy.