Effect of upfront HSCT on patients with T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma at high risk of relapse: Single center retrospective observational study on minority rich population

e19014 Background: T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (T-ALL/TLBL) is an aggressive neoplasm of lymphoid tissue. It comprises 15-25% of all cases of ALL. Given the rarity of the disease, data regarding its optimal management remains limited. Hematopoietic stem cell transplant (HSCT) is usually recommended for patients with T-ALL in second or later complete remission (CR). The data on upfront use of HSCT in ethnic minority rich population is rare. Methods: We conducted a single-center retrospective observational study in patients diagnosed with T-ALL who were followed at our center from 2004-2022. We collected and analyzed data on demographics, race, treatment regimens including HSCT, and survival outcomes. Overall survival (OS) was compared using the Kaplan-Meier curve and log-rank test. P-values < 0.05 were considered as statistically significant. Cox proportional hazards regression model was used for the statistical analysis of prognostic factors and analyses were performed using R software. Results: We identified 59 unique records with this diagnosis (78% males, 22% females). The median age at diagnosis was 20 years (range 1-48 years). Sixty one percent were ethnic minority (32% African American, 29% Hispanic), 17% were white, and 14% were of other ethnicities. Patients were treated at diagnosis with conventional chemotherapy regimens. Our transplant cohort had 10 patients, eight of whom received an allogeneic graft (2 matched related donor, 4 matched unrelated, 1 haploidentical, and 1 cord blood transplant) and 2 an autologous graft. Eight out of 10 patients received HSCT in CR1, 1/10 patient in CR2 (remission data-not available 1/10 patient). The OS of patients transplanted in CR1 did not differ significantly from the patients not receiving HSCT in CR1 (p = 0.5) with OS rates at 12, 24, and 36 months of 87.5% vs 83%, 75% vs 77%, 60%vs 77% respectively. However in the patients who eventually relapsed (n = 13), OS was significantly higher in patients receiving upfront HSCT in CR1 (n = 8) vs patients receiving chemotherapy only (p = 0.013). Furthermore, the OS from the transplant date compared between patients of age (at the time of transplant) < / = 20 years vs > 20 years didn’t differ significantly with p values of 0.29. Conclusions: Our study in T-ALL patients from a mainly minority urban population in NYC showed OS was not significantly different when transplant patients were compared to patients receiving only chemotherapy. For patients who eventually relapsed, the OS for patients receiving upfront HSCT was significantly higher than patients receiving chemotherapy only. Hence, patients at high risk of relapse might benefit from upfront HSCT. However, due to small sample size, evaluation of the effects of confounders was limited in our study.