Survival benefit of autologous transplant (ASCT) for mantle cell lymphoma (MCL) in the California Cancer Registry (CCR).

e19043 Background: Extended follow up of the prospective Nordic MCL2 cohort shows ASCT in CR1 confers a median OS (mOS) of 12.7 y (Eskelund, BJH 2016). Incorporation of BTK inhibitors in 1L MCL is challenging the role of ASCT in an ongoing prospective trial (TRIANGLE, ASH 2022). The present study aims to evaluate the role of ASCT and the impact of social determinants of health (SDH) in a diverse real-world population of MCL patients. Methods: Adult MCL patients diagnosed from January 1, 2000 to December 31, 2020 in the CCR were identified with ICD-O-3 code 9673. The study was approved by UCLA IRB. OS was estimated using KM statistics, calculated from diagnosis to death/last follow-up. Univariate Cox proportional hazards modeling for lymphoma-specific survival (LSS) was performed for variables of interest; those significant at p ≤ 0.10 were incorporated in a stepwise multivariable regression excluding patients with missing data. Socioeconomic status (SES) variables were reported using census-block group data at diagnosis. Results: 5740 ethnically diverse patients were included (NH Whites, n=4038; NH Black, n=175; Hispanic, n=1057; Asian/Pacific Islanders, n=400). Median age at diagnosis was 69 y (IQR 61–68) and 71% were males. 4096 (71%) and 1346 (23%) patients received chemoimmunotherapy and were treated at an NCI/NCCN center, respectively. With a median follow-up of 33 m (IQR 9–76), mOS of the entire cohort was 4.4 y. ASCT patients (n=652, 11%) had improved mOS compared to non-ASCT (14.2 y vs 3.7 y, respectively p<0.001), and 100-day TRM was 2.5%. In the univariable model for all subjects, age, Charlson Comorbidity Index (CCI), married, chemoimmunotherapy, ASCT, NCI/NCCN center, insurance, period of diagnosis, and community SES, poverty, and education were prognostic for LSS. Race, sex, and rural residence were not associated with LSS. Multivariable analysis of 4148 subjects showed significant predictors of LSS were age ≥ 70 y (HR 1.71, p<0.001), ASCT (HR 0.54, p<0.001), diagnosis after 2013 (HR 0.78, p<0.001), CCI (Ref 0; 1-2 HR 1.22, p<0.001; 3+ HR 1.94, p<0.001), married (HR 0.86, p=0.003), NCI/NCCN treatment center (HR 0.77, p=0.001), higher education (top 40% with high school diploma vs. bottom 20%, HR 0.70, p<0.001), higher overall SES (medium vs. low SES tertile, HR 0.81, p=0.003), and increased community poverty (middle 40% vs. bottom 20%, HR 1.14, p=0.043). Conclusions: Our data represent the largest real-world cohort describing the role of ASCT and SDH in MCL. A minority of patients received ASCT and had improved OS compared to non-ASCT patients. While follow-up of ongoing prospective studies will clarify the role of ASCT using contemporary 1L regimens, the present data suggest ASCT in select patients results in durable response with low TRM. Socially disadvantaged patients should be identified and offered supportive programs early in the disease course to mitigate inferior outcomes.