Fluorescence in situ hybridization on peripheral-blood specimens is a reliable method to evaluate cytogenetic response in chronic myeloid leukemia

Purpose: To evaluate the usefulness of fluorescence in situ hybridization ( FISH) on peripheral-blood specimens to evaluate the cytogenetic response to treatment in patients with chronic myeloid leukemia (CML). Patients and Methods: In a first attempt, we analyzed 62 bone marrow specim ens using interphase FISH and compared the results with those of convention al cytogenetics. In a second step, we analyzed 60 paired sets of bone marro w and peripheral-blood specimens with interphase FISH. Results: The results of interphase FISH agreed with conventional cytogeneti cs on bone marrow for most patients, and only minor differences were found (r = .98). The comparison of interphase FISH on bone marrow versus peripher al-blood specimens showed a strong correlation between these two specimen s ources (r =.97). Conclusion: Our results confirmed that FISH is a sensitive technique for th e evaluation of response to treatment in patients with CML. Moreover, our s tudy suggests that follow-vp of cytogenetic response to therapy can be eval uated on peripheral-blood specimens, thus enabling an easier and more frequ ent evaluation of patients. The next step will be to evaluate this techniqu e in a large prospective trial to define the prognostic value of:complete r emissions evaluated by FISH. (C) 2000 by American Society of Clinical Oncol ogy.