Radiotherapy Compared to Other Strategies in the Treatment of Stage I/II Follicular Lymphoma: A Study of 404 Patients with a Median Follow-Up of 15 Years.

PURPOSE: To investigate outcome for patients with follicular lymphoma (FL) stage I-II treated at a population-based referral institution with a median follow-up of 15 years. Overall and cause-specific survival was compared to that of a sex, age and residency matched individuals from normal population.

MATERIAL AND

METHODS

404 patients with early stage FL treated between 1980 and 2005 were retrospectively analyzed. Two of three patients had stage I disease. Based on clinical characteristics, first line treatments were radiotherapy (RT) (48% of patients), chemotherapy (CT) (16%), combined chemo-and radiotherapy (CRT) (16%) or observation (OBS) (15%). Survival was modeled with Kaplan-Meier methodology. Multivariate analyses were performed with the Cox model.

RESULTS

Fifteen years overall survival (OS), progression free survival (PFS) and time to next treatment (TNT) were 50% (95% confidence interval [CI]: 45-55), 42% (95% CI: 36-47) and 48% (95% CI, 42-54), respectively. For patients treated with RT 97% achieved a complete remission, and 15 year OS, PFS and TNT were 57% (95% CI, 50-64), 46% (95% CI, 39-54) and 49% (95% CI, 42-57), respectively. Relapse rate after RT and CRT was 49% and 36%, respectively. Only 2% of patients who received RT or CRT relapsed inside the radiation field and 5% had isolated near-field relapse. No statistical differences were found between treatment groups regarding death from cardiovascular disease or incidence of second cancer. Compared to a matched normal population, non-lymphoma cancer mortality was higher among patients given RT, hazard ratio 1.66 (95% CI: 1.14-2.42; P<0.01). Compared to other treatment modalities, patients selected for observation without treatment did not have inferior outcome.

CONCLUSIONS

A differentiated treatment strategy in early stage FL results in long term survival for the majority of patients. OBS is a valid initial choice for selected patients without lymphoma-related symptoms.