Childhood acute lymphoblastic leukaemia; epidemiology and clinicopathological features.

OBJECTIVE: To study epidemiology, clinical presentation and laboratory features of childhood Acute Lymphoblastic Leukaemia.
METHOD: This retrospective review included all newly diagnosed children with acute lymphoblastic Leukaemia less than 15 years of age registered from April 1999 to December 2004 at oncology unit of National Institute of Child Health and Children Cancer Hospital, Karachi. The objective was to look for epidemiological data, the clinical features and laboratory findings at presentation and compare it with reported literature.
RESULTS: Acute lymphoblastic Leukaemia constituted 32% (611 /1890) of all cancers in this study. Majority of patients hailed from Karachi (59%) and interior Sindh (27%) while rest from other parts of country. Patient's referral increased over the years, from 42 in 1999 to 127 in 2004. The age ranged between 3 months to 15 years with a median age of 6.5 years. Male to female ratio was 1.7:1 Family history of cancer was present in 5% of patients. Fever and pallor were the commonest presenting features. Anaemia (86%), lymphadenopathy (75%) hepatomegaly (67%) and splenomegly (58%) were common findings on physical examination. Initial high white cell count (> 50,000) was observed in 34% patients. Haemoglobin < 7gm/dl was seen in 54% and Platelet counts less than 20,000 was observed in 33% cases. CNS disease was present in 5% and HBsAg was positive in 14% patients at diagnosis.
CONCLUSION: Acute Lymphoblastic Leukaemia accounts for one third of total registered cases. Age distribution in this series shows less prominemt early peak and more significant late peak and a median age of 6 years. Consangunity was found in 47% cases. The fraction with a WBC count above 50,000 mm3 (30%), a higher proportion with lymphadenopathy (75%) and haemoglobin less than 7 gm/dl (54%) suggest that Pakistani children have significantly higher burdens of Leukaemia cells at presentation. These may have prognostic implication resulting in poor outcome of Leukaemia in this part of the world.