PB1671 HOW WE TREAT T‐CELL ACUTE LYMPHOBLASTIC LEUKEMIA(T‐ALL) IN ADULTS IN MALAYSIA: A SINGLE CENTRE EXPERIENCE

Background: T‐lymphoblastic leukaemia/lymphoma (TALL/LBL) is an uncommon and yet aggressive leukaemia belonging to the T‐cell lineage that can present with or without lymphomatous manifestations. Aims: There is limited data on T‐ALL from developing countries of Southeast Asia. This is a pioneer study done in a tertiary centre with transplant facility, Hospital Ampang. It aims to identify the demographics, clinical presentations, choice of induction treatment, and treatment outcomes. We hope to identify any clinical marker which could prognosticate patient in a centre with limited resources therefore generate an optimal risk‐oriented management and improve the treatment outcome. Methods: This is a 10‐year retrospective analytical study of adult patient diagnosed with T–ALL. Data was obtained from Hospital Ampang electronic database. Recruitment of patients commenced from January 2008 till December 2018. Results: A total of 77 patients with T‐ALL were identified, comprising 20% of all ALL cases treated in Ampang Hospital. T‐ALL more prevalent amongst the Malay population (62.3%, n = 48), followed by Chinese (20.8%, n = 16) and Indian and other ethnicities (16.9%, n = 13). There was a male predominance with a ratio of 3.2:1. Median age at diagnosis was 26 years old (range, 13‐77 years old). 60.8% (n =  45) presented with total white count (TWC) of less than 100 × 10 9 /L and 58.4% (n = 45) had widened mediastinal. Majority of patients present with high tumour burden but only 15.6% (n = 12) experienced tumour lysis syndrome (TLS). There was no significant association found between hyperleukocytosis (TWC > 100 × 10 9 /L) and widened mediastinum on presentation as a predictor for TLS (p‐value 0.406 and 0.577). 60 out of 77 patients were able to be subtyped with early T precursor (ETP) being the commonest (41.6%, n = 25) group. Majority of patients underwent induction chemotherapy for curative purposes (93.5%, n = 72). The induction chemotherapy were mainly GMALL (60%, n = 42), then HyperCVAD (31.4%, N = 22) with less than 10% modified BFM (n = 6) regime. Among them, 33.8% (n = 26) underwent allogenic stem cell transplant (SCT). Median overall survival (OS) was 13 months. The event free survival (EFS) at 2 and 5 years was 22.7% and 14.8% while the OS was 31.7% and 21.2% respectively. Transplanted patients have a better EFS (18.1 months vs 6.5months, p‐value 0.0013),and OS (24.3 months vs 8.5 monthsm p‐value 0.0002) as compared to those without transplant. Factors of age more than 35, cytogenetic abnormality, presenting TW > 100 × 10 9 /L and the choice of induction chemotherapy regimen were not associated with longer OS or EFS. Summary/Conclusion: The diagnosis and therapeutic efficacy for adult T‐ALL remain a challenge to us. T‐ALL often carries a poor prognosis as shown in our cohort too. Unfortunately, no clinical prognostic markers were identified from this study likely because of small sample size. A larger cohort involving Malaysia nationwide and collaboration with other Asian countries will help to identify the prognostic marker in T‐ALL patients in this region.