Adult Acute Lymphoblastic Leukemia and Cytogenetic Abnormalities in Different Racial and Ethnic Subgroups.

Inferior survival of African American and Hispanic patients with acute lymphoblastic leukemia (ALL) has been reported. The reason for this is unclear. A retrospective analysis was conducted to see if abnormal cytogenetics account for the differences. We have analyzed cytogenetic studies of 39 adults (16 year and older) with newly diagnosed ALL who were consecutively treated at John Stroger Hospital of Cook County between 1997 and 2005. The study population included 13 (33%) African Americans, 18 (46%) Hispanics, 6 (16%) Caucasians, and 2 (5 %) other ethnic background adults. Male to female ratio was 2:1. Mean age at diagnosis was 26 (range between 16 and 71 years). A clonal cytogenetic abnormality was detected in 27 patients, and 12 patients had normal karyotype. Patients with t (9;22)(q34;q11), BCR-ABL + by FISH, t (4;11)(q21;q23), +8, −7 cytogenetic abnormalities were assigned to an unfavorable cytogenetic group. This group was composed of 14 patients. None of our study patients had favorable cytogenetics: del (12p), t(12p), t(14q11-q23), inv(14)(q11;q32) or t(10;14)(q24;q11). Remaining 25 patients with normal karyotype (n=12) or miscellaneous cytogenetic abnormalities (n=13) were classified as normal risk group. 54 % of African Americans had unfavorable cytogenetics, compared with 33 % Caucasians and 17 % Hispanics. Translocation t (9;22) alone or in association with other cytogenetic abnormalities was most commonly seen. 9 patients had single, and 18 had multiple chromosomal changes. Hispanic group had more complex cytogenetic changes when compared with the African American or Caucasian groups. Unfavorable cytogenetic abnormalities may account for inferior survival in African Americans, but other factors such as compliance or pharmacogenetics should be evaluated, especially in the Hispanic patient population.