Clinical features and outcome of T-cell acute lymphoblastic leukemia in patients older than 9 years: A single center experience of 110 patients from AIIMS, New Delhi, India.

Abstract

7081 Background: It is known that T cell acute lymphoblastic leukemias (ALL) have poorer outcomes than their B cell counterparts. Data on T-ALL in the age group of >9 years from India is minimal. Methods: This is a single institutional analysis of patients of above 9 years who were treated from January 2000 to December 2010. All patients who completed at least 4 weeks of induction therapy were analysed for various outcomes. Results: T-ALL formed 30% of all ALL in this age group. Of the 110 newly registered patients of T-ALL, the median age was 17 years (Range 10-50 years) with an M:F ratio of 5.9:1. Of this 62%, 30% and 18% patients belonged to 10-18, 19-30 and > 31 years age group respectively. Eighteen (19%) and 2 (2%) and 33 (30%) had CSF, testicular and other extramedullary sites involvement respectively. Twenty eight per cent had a total leucocyte count (TLC) of above 100x109/L. Patients available for survival analysis were 104(94.5%). Complete remission (CR)rate was 68.2% and induction mortality was 14.4%. At a median follow up of 56.4 months 5 year leukemia free survival was 52.3% (median not attained). Twenty seven (38%) patients relapsed (median relapse time of 15.2 months, range 0.7 to 47.3 months), 55% during maintenance phase. The 5 year overall survival (OS) was 46.9% (median OS of 35.4 months). The 5 year OS of 10-18, 19-30 and > 31 years age groups were 42.8%, 71% and 16.6% respectively (p value not significant). Not attaining CR in 1st induction, spontaneous tumor lysis syndrome and peripheral blood blast count of > 80% were significant poor prognostic factors for survival. Conclusions: This is one of the largest study of T-ALL outcomes in patients above 9 years from a single center from India. Attainment of CR in 1st induction was the most important risk factor for survival. 5 year OS was 47%.