Adult precursor B lymphoblastic leukemia in Shanghai, China: characterization of phenotype, cytogenetics and outcome for 137 consecutive cases.

Acute lymphoblastic leukemia (ALL) accounts for 20-30% of adult leukemia in the West. However, detailed studies of B-cell-specific ALL in adult Asian populations are lacking. We diagnosed and characterized 137 consecutive cases of precursor B lymphoblastic leukemia (precursor B-cell ALL) presented to our laboratory in Shanghai using the WHO 2001 classification system. Patient clinical, phenotypic and cytogenetic characteristics were correlated with outcome. In contrast to Western studies, females (71) outnumbered males (66) partly due to an increased prevalence of the CD10- pro B-cell phenotype. Females with a CD10- pro B-cell phenotype exhibited significantly better overall survival than males. The most common cytogenetic abnormality was the Philadelphia chromosome (PH/BCR/ABL) which was found in approximately 37% of the cases. Cases of precursor B cell ALL lacking the PH/BCR/ABL genotype exhibited a pronounced age-dependent, gender prevalence with a modal age in the sixth decade for females compared to the second decade for males. These findings suggest significant geographic heterogeneity in precursor B-cell ALL which may be of both etiological and therapeutic significance.