Primary nasal natural killer cell lymphoma: Long-term treatment outcome and relationship with the International Prognostic Index

Abstract

Nasal natural killer (NK) cell lymphoma is rare, so that its optimal therapy, longterm outcome, and prognostic factors are unclear. Data on 52 men and 15 women with well-characterized nasal NK cell lymphomas were analyzed retrospectively to define the impact of primary therapy on remission and long-term outcome and the validity of the International Prognostic Index (IPI). Most (84%) had stage I/II disease with an IPI score of 1 or less (52%). Seven patients received radiotherapy only; 47 patients received anthracycline-containing chemotherapy plus consolidation radiotherapy; and 12 patients received nonanthracycline-containing chemotherapy plus radiotherapy. The overall complete remission (CR) rate was 64.2%; the 20-year overall survival (OS) and disease-free survival (DFS) rates were 37.1% and 33.5%, respectively. Front-line radiotherapy was apparently better than chemotherapy for CR (100% versus 59%, P= .04) and OS (83.3% versus 32.0%, P= .03). Relapses occurred in 4 radiotherapy-treated (all local) and 14 chemotherapy-treated patients (9 local, 4 systemic). Among these, 5 late relapses (4 local, 1 systemic) occurred at 170 months (range, 92-348 months) from CR. The IPI score was of prognostic significance for the whole group (IPI ≤ superior to IPI ≥ 2 for 20-year OS: 57.4% versus 27.6%, P = 0.012), as well as for patients treated with chemotherapy/radiotherapy (IPI ≤ 1 superior to IPI ≥ 2 for CR: 76.7% versus 35.7%, P = .017; and 10-year OS: 63.8% versus 26.8%, P = .003). © 2004 by The American Society of Hematology.