B-cell and T-cell acute lymphoblastic leukemia
Individualized test options for each patient
In the United States, the incidence of acute lymphoblastic leukemia (ALL) is approximately 1 in 50,000. Acute lymphoblastic leukemia accounts for approximately 70% of all childhood leukemia cases (ages 0 to 19 years), making it the most common type of childhood cancer. Approximately 85% of pediatric cases of ALL are B-cell lineage (B-ALL) and 15% are T-cell lineage (T-ALL). It has a peak incidence at 2–5 years of age. The incidence decreases with increasing age, before increasing again at around age 50.
A combination of cytogenetic and FISH testing is currently recommended in all pediatric and adult patients to characterize the B-ALL and T-ALL clones for the prognostic genetic subgroups. Each of the genetic subgroups are important to detect, can be critical prognostic markers, and can assist in treatment selection.
A newly recognized World Health Organization (WHO) entity BCR-ABL1-like ALL, also known as Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL), is increasing in importance due to the poor prognosis seen in pediatric, adolescent, and young adult ALL. Common features of this entity involve rearrangements with tyrosine kinase genes involving the following: ABL2, PDGFRB, JAK2, ABL1, CRLF2, P2RY8, and deletions involving IKZF1. Patients who have failed conventional therapies have demonstrated favorable responses to targeted therapies when rearrangements involving these specific gene regions have been identified.
Comprehensive testing, simplified
Our approach to fluorescence in situ hybridization (FISH)testing is designed to simplify the ordering process by providing diagnostic panels that include all appropriate genes.
BALAF | Adult ALL (B-cell), FISH panel
A Test in Focus
Horatiu Olteanu, M.D., Ph.D., gives an overview of the new T-cell receptor (TCR) β-chain constant region (TRBC1) flow cytometry marker, which is now included in Mayo Clinic Laboratories' routine diagnostic T-cell flow cytometry panel. He discusses when this testing should be ordered, how the addition of TCRBC1 compares to previous testing approaches, and how this marker can assist ordering physicians.
Learn more about how to order these evaluations at your institution.