Chen, Wanqi

BackgroundAlthough many patients with follicular lymphoma (FL) undergo routine radiographic surveillance during their first remission, no consensus exists on the modality, duration, frequency, or need for routine imaging studies. The authors retrospectively examined the effect of surveillance imaging on relapse detection and overall survival (OS) in patients with FL.MethodsPatients with newly diagnosed FL who had a response to induction therapy were identified from the Lymphoid Malignancies Enterprise Architecture Database (LEAD) at Emory University and from the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic. Patients were evaluated for both relapse and method of relapse detection (ie, clinical concerns vs radiologic detection through surveillance imaging in an asymptomatic patient).ResultsOf 148 patients in the LEAD cohort, 55 (37%) relapsed, and the majority (n = 35; 64%) of relapses were detected clinically. In the MER cohort, 63 of 177 relapses (54%) were detected clinically. There was no significant difference in OS from the date of diagnosis between the 2 methods of relapse detection in the LEAD (hazard ratio [HR], 0.61; 95% CI, 0.13‐2.94; P = .54) and MER (HR, 1.02; 95% CI, 0.47‐2.21; P = .96) cohorts. Similarly, there was no significant difference in OS from the date of relapse between the 2 methods of relapse detection in the LEAD (HR, 0.47; 95% CI, 0.10‐2.27; P = .35) and MER (HR, 1.02; 95% CI, 0.47‐2.21; P = .96) cohorts.ConclusionsThese findings suggest a limited role for routine surveillance imaging in patients with FL who complete front‐line therapy. Future studies should evaluate which patients may benefit from a more aggressive surveillance approach and should explore novel methods of relapse detection.

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.

e15029 Background: ICIs induce durable responses in dMMR CRC pts with overall response rates (ORR) of 30-50%. Even though the loss of expression of any MMR gene predicts ICIs response, it is unknown if ORRs are similar across all MMR genes (MLH1, PMS2, MSH2, and MSH6). In this study, we analyzed the impact of each specific MMR gene loss and clinical characteristics of pts with best response to ICIs. Methods: Pts were eligible if they had confirmed dMMR CRC by IHC or microsatellite instability-high (MSI-H) by PCR, and received ICIs between 01/01/2012 and 10/01/2018 at Winship Cancer Institute of Emory University, Mayo Clinic or Vanderbilt University Medical Center. Due to the pattern of frequent concurrent loss and functional dependency, the groups were categorized as MLH1 ±PMS2 vs. MSH2 ±MSH6. Cox proportional hazard model and Fisher’s exact test were used for the best response and the distribution of variable among the subgroups. Results: A total of 45 pts with dMMR CRC were identified. ORRs in MLH1 ±PMS2 and MSH2 ±MSH6 groups were 68% and 57.1% respectively without statistical difference (Table). Pts with age < 50 and 50-65 years old had better ORRs compared to pts with age >65 (58.3%, 85.7% and 42.1% respectively, P=0.036). Left-sided tumors had a trend toward higher ORRs compared to right-sided tumors (83.3% vs 51.5% P=0.086). Gender and BRAF status were not predictors of response. BRAF mutations were more common in right-sided tumors (29.6% vs 11.1% respectively) and in older patients. Conclusions: Our data suggest that MSI-H CRC pts aged 50-65 treated with ICIs, have improved ORR compared to pts > 65; pts with left-sided tumors have a trend toward improved ORR compared to those with right sided tumors. [Table: see text]