Acute lymphoblastic leukemia in India: An analysis of prognostic factors using a single treatment regimen

Background: In the past, treatment results in Indian children with ALL have been poor, primarily due to inadequate chemotherapy and supportive care, b ut perhaps reflecting differences from Western countries in the pattern of subtypes. In an attempt to improve survival, we have used a more intensive treatment protocol, MCP841, and examined prognostic factors. Patients and methods: Five hundred thirty previously untreated patients <25 years of age with ALL were entered on study at the Tata Memorial Hospital, Mumbai. Treatment consisted of three successive induction cycles, consolid ation and six maintenance cycles. CNS prophylactic therapy consisted of cra nial irradiation (2000 cGy) for patients above two years and high-dose cyta rabine for patients less than two years. The total treatment duration was t wo years. Results: Most patients had hepatosplenomegaly (80%) and/or lymphadenopathy (79%) and 21% were of T-cell immunophenotype, but very few (1.3%) had CNS d isease. CR was achieved in 484 (91.3%) patients and 145 (29.9%) patients re lapsed. There were 36 induction deaths and 49 remission deaths, but the tox ic death rate was significantly lower after 1990. In patients treated since 1990, three risk groups could be discerned: 1) WBC <60,000 per mm(3) and n o lymphadenopathy (77% event-free survival (EFS) at five years); 2) WBC <60 ,000 per mm(3) with lymphadenopathy (53% EFS) or, WBC > 60,000 per mm(3) an d Hb 6 gm/dl or above (48% EFS); and 3) WBC > 60,000 per mm(3) and Hb below 6 gm/dl (16% EFS). In a multivariate model, only WBC, Hb and lymphadenopat hy were significantly associated with EFS (P < 0.01). Conclusions: The CR and EFS rates achieved represent a significant improvem ent over previous results at this institution. Bulky extramedullary disease was an important risk factor in this series, but age and WBC alone inadequ ately defined risk groups, suggesting that prognostic factors may vary in d ifferent world regions.