Survival in Adult Stage I Follicular Lymphoma Treated with and without Radiotherapy – a Population Based Study

Abstract

Introduction:NCCN guidelines recommend involved site radiotherapy is the preferred treatment option for Stage I follicular lymphoma. Other options include immunotherapy, immunotherapy ± chemotherapy, immunotherapy ± chemotherapy + involved site radiotherapy and observervation only. Studies have not shown overall survival benefit with one modality over other. We conducted this study to evaluate survival rate among patients who are treated with observation alone or external beam radiation.Methods:We selected patients with stage I follicular lymphoma diagnosed during 1992-2006 from Surveillance, Epidemiology and End Results (SEER) 18 database. We analyzed 1- and 5-years relative survival (RS) rates using SEER*stat program. We used Z test to compare relative survival rates of patients treated with (RT) or without radiotherapy (no RT) by age (>18 years, 18-60 years and >60 years) and sex.Results:A total of 1914 out of 5,145 adults patients with stage I follicular lymphoma diagnosed during 1992-2006 received radiotherapy. 1- and 5- year RS in patients with out vs with EBT were : 96.1 vs 100% ( Z value 6.9/ p value < 0.001) and 89.3 vs 98.7%.( Z value: 7.6/ p value < 0.001). The survival rates were significantly higher in the RT group for younger patients (1 year: 98.4 vs 100%; Z value 2.99/ p value < 0.01 and 5 year: 93.2 vs 98%; Z value 4.45/ p value < 0.001) and older patients (1 year: 94.6 vs 100%; Z value 5.8/ p value < 0.001 and 5 year: 86.5 vs 99.2%; Z value 6.21/<p value < 0.001).Similarly 1- and 5-yr RS rates were significantly higher in the RT group compared to no RT group for all cohorts (Table 1).Conclusion:This study showed that relative survival rates of stage I follicular lymphoma patients receiving radiotherapy were significantly better compared to those who did not receive radiotherapy. Abstract 1317. TableSexAge in yearssurvival yearsNo External Beam RadiationExternal Beam RadiationZ value/ p valueNRelative survival ± SE %NRelative survival ± SE%Male and female≥1813,23196.10±0.401,914100.00±0.006.90/<0.001589.30±0.9098.70±0.807.61/<0.00118-6011,26398.40±0.40932100.00±0.203.00/<0.01593.20±0.9098.00±0.704.45/<0.001≥6111,96894.60 ±0.70982100.00±0.005.81/<0.001586.50±1.3099.20±1.506.21/<0.001Male≥1811,53195.50±0.70983100.00±0.006.05/<0.001587.30±1.30100.0±0.007.55/<0.001Female≥1811,70096.70±0.6093199.70±0.503.34/<0.001591.00±1.2096.20±1.302.75/<0.01Table 1: 1 year and 5 year relative survival of Follicular lymphoma stage I treated with and without external beam radiation DisclosuresNo relevant conflicts of interest to declare.