[Prognostic factors and treatment outcome in early stage nasal NK/T cell lymphoma]

To analyze initial response rate of radiotherapy and chemotherapy for early nasal NK/T-cell lymphoma, and its prognostic factors.

From January 1996 to December 2002, 116 patients with nasal NK/T-cell lymphoma were diagnosed pathologically. Immunophenotyping was performed in 50 cases. According to Ann Arbor staging classification, 95 patients were stage I(E) and 21 II(E). Of the 116 patients, 22 received radiotherapy alone, 6 chemotherapy alone and 88 combined modality therapy (CMT), including, 41 radiotherapy followed by chemotherapy, and 47 chemotherapy followed by radiotherapy.

The 5-year overall survival (OS) rate and disease free survival (DFS) rate for all patients was 74.1% and 61.5%, respectively. For stage I(E) and II(E) patients, the 5-year OS rate was 75.1% and 68% (P = 0.45), and DFS rate was 64.7% and 47.8%, respectively (P = 0.07). The 5 year OS rate and DFS rate were 86.5% and 71.5% for patients who achieved complete response (CR), and 18.4% and 17.2% for those who didn't, respectively (P = 0.000). Sixty-three patients were treated with radiotherapy alone or radiotherapy followed by chemotherapy, while 53 with chemotherapy followed by radiotherapy or chemotherapy alone. The CR rate for radiotherapy was 74.6% while for chemotherapy was 20.8% (P = 0.000). The 5-year OS rate and DFS rate were 76.8% and 65.4% for radiotherapy with or without chemotherapy, and 78.8% and 61.8% for chemotherapy followed by radiotherapy (P > 0.05). Multivariate analysis by COX regression showed that CR rate was the only independent prognostic factor.

The CR rate of radiotherapy is much higher than that of conventional chemotherapy. Addition of chemotherapy to radiotherapy do not improve the survival of patients with early stage nasal NK/T-cell lymphoma. Radiotherapy is the primary treatment for stage I and II nasal NK/T-cell lymphoma.