Genomic profiling of myeloma: the best approach, a comparison of cytogenetics, FISH and array-CGH of 112 myeloma cases

Abstract

Background: Chromosome abnormalities are important prognostic factors in myeloma allowing risk stratification of patients. Different techniques are available for their detection including cytogenetics, Fluorescent In Situ Hybridisation (FISH) and array Competitive Genomic Hybridisation (CGH). This study aimed to assess the validity and usefulness of each technique in a diagnostic setting.

Methods: 112 myeloma cases were analysed by whole bone marrow cytogenetics and by FISH and array CGH performed on purified plasma cell populations.

Results: Clonal abnormalities were identified in 30% of cases by cytogenetics and 97% by FISH and array CGH. By combining array and FISH results abnormalities were detected in 99% of cases and, if cytogenetic analysis was also considered, abnormalities were detected in 100% of cases.

Conclusions: Cytogenetic analysis is of limited value in myeloma. Array CGH and FISH are highly specific tests allowing the identification of aberrations in virtually all cases. The two techniques are complementary and need to be combined in order to provide a comprehensive analysis of all clinically relevant aberrations in myeloma.

Keywords: ANALYTICAL METHODS; CYTOGENETICS; FISH; MICRO ARRAY; MYELOMA.