The Detection of Genomic Abnormalities and Prognostic Stratification in Plasma Cell Myeloma Using Array-Based Karyotyping Post Plasma Cell Enrichment
Luise Hartmann, Christine F Stephenson, Krystal R Johnson, Douglas B Chapman, Denise A Wells, Michael R Loken, Budi Tirtorahardjo, Shelly R Gunn, Lony C Lim, Monica E de Baca, Barbara K Zehentner. HematoLogics, Inc., Seattle, WA; Combimatrix Inc, Irvine, CA; PLUS Diagnostics, Irvine, CA
Background: Plasma Cell Myeloma (PCM) is a hematopoietic neoplasm characterized by malignant plasma cells. The discovery of genomic abnormalities present in the monoclonal plasma cells has diagnostic, prognostic as well as disease monitoring implications. However, technical and disease-related limitations hamper the detection of these abnormalities by metaphase cytogenetic analysis or FISH.
Design: In this study, we tested 35 bone marrow specimens with known plasma cell neoplasm for the presence of genomic abnormalities using microarray analysis post plasma cell enrichment and compared the results with other laboratory findings. Conventional cytogenetic studies were performed on 22 of the 35 samples.
Results: Cytogenetic studies identified disease related genomic aberrations in only 5 of the 22 cases (23%) due to the low proliferative rate of plasma cells. In contrast, 91% of specimens tested positive by plasma cell-FISH and all 35 cases carried abnormalities identified by array comparative genomic hybridization (aCGH). Furthermore, aCGH was superior in risk stratification: prognostic stratification was possible in 91% of tested samples, compared to 39% of cases analyzed by FISH.
Conclusions: We conclude that the combination of plasma cell enrichment and genomic copy number assessment using CGH microarray is a valuable approach for routine clinical use to achieve a more complete genetic characterization of plasma cell myeloma patients.
Monday, March 4, 2013 11:15 AM
Proffered Papers: Section C, Monday Morning