Impact on Survival of Surveillance Imaging after First Remission in Follicular Lymphoma.

7536 Background: While most patients (pts) with follicular lymphoma (FL) achieve an initial response to treatment, the majority relapse. Recently, Goldman et al. reported that surveillance imaging (SI) in FL is not associated with improved post-relapse outcomes and is frequently associated with false positive scans (ASH 2017). The goal of this study was to validate these findings. Methods: Pts were enrolled in the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), a prospective cohort of newly diagnosed lymphoma pts. All pts were followed for events including relapse, re-treatment, and death, with events verified by medical records. Pts eligible for this study had biopsy proven FL grade 1, 2, or 3a who had achieved a response after induction therapy and later relapsed. Initial and post-treatment management was per treating physician. Medical records were re-reviewed in pts with events for clinical details at relapse in relationship to planned follow-up visits and SI. Relapse detection was categorized either by clinical suspicion (CS) via history, exam, and/or labs; or by SI in an asymptomatic pt. Univariate survival analysis was conducted for each variable. The hazard ratio with 95% confidence interval based on Cox Proportional Hazard models was presented along with the log rank test p-value. Kaplan-Meier plots were produced to evaluate the difference in overall survival (OS) between groups. Results: 1121 FL pts were enrolled in MER from 2002-2015, of which 117 were eligible. Median age at diagnosis was 60 years (range 35-83), and 61% were men. Median time to relapse of the 117 pts was 26 months (range 9-125). At a median follow-up from relapse of 69 months (range 0.23-179), 26 pts died. Pts completed a median of 3 imaging studies (range 0-15) during post-induction surveillance. 63 relapses (56%) were detected based on CS; 50 (44%) were detected by SI; and 4 were unknown. There was no difference in OS from relapse for those with relapse detected via CS vs. SI (HR = 0.98 [0.45,2.12], p = 0.96). Conclusions: Routine SI does not appear to improve survival outcomes in FL after achieving first remission, and its common practice should be questioned. Further investigation of prognostic markers to identify high-risk FL pts who may benefit from SI is needed.