Hematopoietic malignancies include
leukemia,
lymphoma and
multiple myeloma. These diseases are primarily diagnosed on the basis of morphological features of affected cells, which appear in peripheral blood, bone marrow and lymphoid organs. By taking advantage of the repetitive accessibility of the neoplastic cells within the peripheral blood / and/or bone marrow aspirates, morphological tests are conducted not only for diagnosis but also for evaluation of clinical outcomes and prognosis, suggesting that the morphological features are considered as a clinical
biomarker in
hematopoietic malignancies. However, remarkable progress in
molecular targeted therapy and allogeneic
hematopoietic stem cell transplantation has improved the long-term prognosis of patients with
hematopoietic malignancies, and some patients are curable. Under such modern strategies for
therapy, monitoring of
minimal residual disease(MRD), which is morphologically undetectable, is required to guide proper management of the disease by evaluation of an optimal response to
therapy and early detection of disease relapse. At present, both immunophenotypes(surface markers)and chimeric fusion genes(e. g. BCR-ABL in
chronic myeloid leukemia)characteristic of hematopoietic malignant cells are analyzed as clinically useful
biomarkers to monitor MRD by two highly sensitive methods, multiparameter flow cytometry and real-time quantitative PCR, respectively. On the other hand,
serum markers reflecting the size of the
tumor mass are clinically available to monitor the
disease progression in mass-forming
hematopoietic malignancies: e. g., soluble
IL-2 receptor for
lymphoma and M-
protein or free light chain for
multiple myeloma.