Long-term outcomes of patients with newly diagnosed extranodal natural killer/T-cell lymphoma treated by etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin regimen: a single-institution experience.

One possible reason for the relapse and refractoriness of extranodal natural killer/T-cell (NK/T) lymphoma (ENKL) is resistance to a CHOP-like regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone). To evaluate the outcome of first-line EPOCH chemotherapy (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) for ENKL, 34 patients, including 30 with nasal ENKL (88.2%) and four with extranasal ENKL (11.8%), were studied. Involved-field radiation therapy (IFRT) was administered to patients with localized nasal focus after chemotherapy. Thirty-three cases were eligible for response evaluation. The response rate (RR) was 60.6% (20/33) with a complete remission (CR) rate of 45.5% (15/33). For patients with localized nasal ENKL, the CR rate was 57.7% (15/26). The 3-year progression-free survival and overall survival rates were 53.6% and 69.0%, respectively. After initial EPOCH chemotherapy followed by IFRT, the CR rate was 75.0% and the 3-year overall survival rate was 75.0%. However, patients with disseminated and extranasal disease responded poorly. These results indicate that EPOCH followed by IFRT yields promising outcomes for patients with localized nasal ENKL.