ABSTRACT

Chronic myeloid leukemia (CML) is well suited to molecular monitoring as rising and falling levels of breakpoint cluster regions (BCR)-Abelson (ABL) transcript, measured by real time quantitative polymerase chain reaction (RQ-PCR) from venous peripheral blood correlate well with disease progression and remission. This chapter discusses molecular monitoring in the imatinib era, focusing on treatment that began in early chronic phase disease. The leukemia specific BCR-ABL transcript is a well-suited target for molecular monitoring as nearly all patients with CML have one of two transcript types eliminating the requirement for patient specific primers. Recent recommendations from expert panel on behalf of European LeukemiaNet suggest criteria for determining whether treatment response is adequate at a particular treatment time point and whether change in therapy should be considered. The International Randomized Study of Interferon versus STI571 study established the superiority of 400 mg of imatinib daily over interferon and low dose cytosine arabinoside in a prospective randomized study of 1106 chronic phase patients.