DETECTION OF MINIMAL RESIDUAL DISEASE - RELEVANCE FOR DIAGNOSIS AND TREATMENT OF HUMAN MALIGNANCIES

Minimal residual disease (MRD)is the tumor burden that is present afte r a course of treatment that has resulted in clinical remission. For h ematopoietic malignancies, techniques for detection of this minimal tu mor burden are being used to monitor MRD. These involve methods that a re capable of identifying very low numbers of neoplastic cells in an o therwise normal marrow or lymph node. Patients with demonstrable resid ual neoplastic cells tend to do worse than patients without detectable cells; however, results depend on the timing of the assay and whether the detectable neoplastic cells appear to be increasing in number wit h subsequent assays. For bone marrow transplantation, assays incorpora ting chimerism analyses, cytogenetics, and morphology are used to regu late therapy.