Purpose: To evaluate prospectively in patients with follicular lymphoma and a low tumor burden three therapeutic options: delay of any treatment until clinically meaningful progression, immediate treatment with an oral alkylating agent, or treatment with a biologic response modifier, interferon alfa-2b.
Patients and methods: Newly diagnosed follicular lymphoma patients with a low tumor burden (n = 193) were randomly assigned to one of three arms: arm 1, no initial treatment (n = 66); arm 2, prednimustine 200 mg/m2/d for 5 days per month for 18 months (n = 64); or arm 3, interferon alfa 5 MU/d for 3 months then 5 MU three times per week for 15 months (n = 63). Clinical characteristics were similar in the three arms.
Results: Overall response rates with prednimustine and interferon alfa were 78% and 70%, respectively. The overall response to therapy, when deferred, was similar at 70%. With a median follow-up duration of 45 months after randomization, the median freedom-from-treatment (FFT) interval was 24 months in arm 1 and the interval of freedom from treatment failure (FFTF) was 40 months in arm 2 and 35 months in arm 3. The median overall survival time was not reached and the overall survival rate at 5 years was 78% in arm 1, 70% in arm 2, and 84% in arm 3. Therefore, deferred treatment does not adversely influence survival at 5 years. Patients who progressed within 1 year had a significantly shorter survival duration (median, 48 months).
Conclusion: Delayed treatment is feasible in patients with follicular lymphoma and a low tumor burden. For patients with early progression, more intensive therapy should be considered. For others, because delay of treatment until significant clinical progression does not seem to hamper the prognosis or subsequent response to treatment, the long-term toxicity of alkylating agents can be reduced.