Purpose: To clarify the role of radiotherapy and chemotherapy in the treatment of patients with localized aggressive non-Hodgkin's lymphomas (NHL) originating in the nasal cavity.
Methods and materials: The survey, administered at 25 Japanese institutes in 1998, enabled us to collect the clinical data for 787 patients with localized aggressive NHL who were treated between 1988 and 1992.
Results: There were 42 patients (5%) with nasal lymphomas. Twelve of these patients received radiotherapy alone, and 30 were treated with a combination of radiotherapy and chemotherapy. The median radiation dose was 47 Gy (22-66). Twelve patients were reviewed histopathologically according to REAL (Revised European-American Classification of Lymphoid neoplasms) classification. T-cell or natural killer (NK) cell lymphomas were detected in 9 patients (75%), and diffuse large B-cell lymphomas in 3 (25%). The 5-year overall and disease-free survival (DFS) rates of all patients were 57% and 59%, respectively. The 5-year DFS rate for the 30 patients treated with the combined therapy was 64% and that for the 12 patients treated with radiotherapy alone was 46% (p = 0.021). For the 34 patients with stage-modified International Prognostic Index (m-IPI) 0-1, the 5-year DFS rates of those treated with the combined therapy and radiotherapy alone were 68% and 45%, respectively (p = 0.020), but there was no difference in DFS rate among the two groups of patients with m-IPI 2-3. The 5-year local control rates of the patients who received >46 Gy (n = 22) and < or =46 Gy (n = 20) were 95% and 76% (p = 0.087), respectively. There was no significant difference among the 5-year DFS rates (62% vs. 67%) and local control rates (87% vs. 100%) of the patients with T-cell or NK-cell lymphoma and diffuse large B-cell lymphoma.
Conclusions: Patients with nasal lymphomas (m-IPI 0-1) should be treated with combined therapy. For the patients with high risk (m-IPI 2-3), the effectiveness of combined therapy was not clarified because of the small number of the patients. A high radiation dose >46 Gy may need to be used to achieve good local control.