Primary diffuse large B-cell lymphoma of the tonsil: is a higher radiotherapy dose required?

The purpose was to evaluate the prognostic factors and treatment outcome of Indian patients with primary diffuse large B-cell lymphoma (DLBCL) of the tonsil treated at a single institution.

In all, 121 patients with DLBCL of the tonsil, treated at the Tata Memorial Hospital, Mumbai, India, from January 1990 to December 2002, were included. The median age was 45 years and the majority of patients (68%) were males. Systemic symptoms were present in 12% of patients; 28% presented with stage I and 67% had stage II disease. Treatment consisted of a combination of chemotherapy (CTh) and radiotherapy (RT) for the majority of patients (69.4%). Among those receiving RT, 64% received an RT dose of > or =45 Gy.

After a median follow-up of 62 months, disease-free survival (DFS) and overall survival (OS) were 66.4% and 81.6%, respectively. Significant prognostic factors included: WHO performance score > or =2 (OS: 72.1% vs 95.6%, P = .016), bulky tumors (OS: 68.5% vs 86.9%, P = .001), presence of B-symptoms (OS: 36.7% vs 79.6%, P < .001), and Ann Arbor stage. On multivariate analysis; WHO performance score > or =2 (hazard ratio [HR], 4.27; 95% confidence interval [CI], 1.20-15.12), and B symptoms (HR, 6.27; 95% CI, 2.38-16.48), retained statistical significance. CTh + RT resulted in a significantly better outcome than those treated with CTh alone (OS: 85.7% vs 70.7%, P = .008). The complete response (P = .053), DFS (P = .039), and OS (P = .014) rates were significantly better for patients receiving an RT dose > or =45 Gy.

Tumor bulk, WHO performance score, the presence of B symptoms, and Ann Arbor stage significantly influence outcome. A combined modality treatment, consisting of CTh and RT (with an RT dose of > or =45 Gy), results in a satisfactory outcome in patients with this uncommon neoplasm.