The cytogenetic response as a surrogate marker of survival

In the management of chronic myeloid leukemia (CML), cytogenetic response (CgR) has been recognized as an important prognostic factor and is used in predicting patient outcome. Imatinib (Gleevec) (formerly STI571), a potent inhibitor of BCR-ABL, is very effective in inducing CgRs in chronic-phase CML patients, even in late chronic-phase patients in whom interferon (IFN) was unsuccessful. This review describes the intrinsic value of a CgR following different forms of nontransplant treatment options for CML. Achievement of major CgR is predictive of prolonged survival with imatinib. In addition, patient prognostic risk score (Sokal or Euro risk score) affects patient outcome. Low-risk patients survive longer than non-low-risk patients given the same CgR. Preliminary results from studies with imatinib are superior and CgR remains an important surrogate marker of survival in the imatinib era.