Clinical Classification and Prognostication of Myeloma
Our laboratory was the first to describe the specific clinical outcome associations with the chromosome translocations in myeloma. Specifically we were able to show that the t(4;14)(p16;q32) and t(14;16)(q32;q23) were associated with a much shorter survival, and we know through the work of ours and others that this is irrespective of treatment modality administered. For a full detailed description of these associations we refer to the publications.
Based on these associations one can observe how myeloma can be clinically classified much the same way this has occurred for acute leukemia.
These associations dictate morphology, cell surface expression, response to treatment, survival, etc. Our belief is such that the determination of these genetic categories is central to the evaluation performed on patients at the time of routine clinic visits. Once we order a bone marrow sample be done for patients with myeloma we ask for a genetic categorization based on the performance of cIg-FISH.
These results are available back from the clinical cytogenetics department and are integrated into the decision making process for the patient.
The t(11;14)(q13;q32) associated myeloma is the best described clinco-pathologic entity. It is observed in 15% of cases of MM and in a slightly higher proportion of patients with MGUS. It has also been described at a higher prevalence in the clonal cells of light chain amyloidosis. Of interest, this translocation has also been described in a very high proportion of the rare entity IgM myeloma. Patients with t(11;14)(q13;q32) more frequently have expression of CD20 in the cell surface and have a tendency towards a better prognosis. They also have a strong association with lymphoplasmacyticmorphology.
The t(4;14)(p16;q32) is one of the most aggressive forms of myeloma. It is associated with a shorter survival and short time to relapse after stem cell transplantation. It is detectable in 15% of cases.
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