[Cheryl G]

Chromosomal abnormalities - new alternative to FISH test

by Cheryl G on Fri Feb 26, 2016 11:10 am

Most of us here are well aware of the fact that chromosomal abnormalities – things like del(17p), t(11;14), and so on –are important for the prognosis of multiple myeloma patients.

These abnormalities usually are detected by carrying out a "FISH" test on plasma cells taken from a bone marrow biopsy. FISH stands for "fluorescence in situ hybridization".

Apparently, there's a new approach to detecting chromosomal abnormalities that we may be hearing about more often in the future. It's called "oligonucelotide-based array comparative genomic hybridization" (oaCGH), or sometimes more simply just "array CGH".

I had not heard of this type of testing approach until I came across a recently published paper that discusses it. As best I can tell, it has the potential to be more accurate than FISH testing.

In any case, here is the paper that discusses it. I've mainly just reviewed the abstract, but the full text is available at no charge, and I think it has more about the array CGH methodology.

E Kjeldsen, "Identification of Prognostically Relevant Chromosomal Abnormalities in Routine Diagnostics of Multiple Myeloma Using Genomic Profiling", Cancer Genomics & Proteomics, March-April 2016 (full text of article)

Abstract

Background:

The combination of serum β2-microglobulin and albumin levels is highly prognostic in multiple myeloma, defined as the International Staging System (ISS). Recurrent genomic abnormalities present in myeloma cells also have a strong prognostic power. This study aimed to assess, in a routine diagnostic setting, whether genomic aberrations can be used to identify sub-groups in ISS staging, as this system does not incorporate intrinsic myeloma cell variability at the molecular level.

Materials and Methods:

A prospective population-based study of 123 patients newly diagnosed with multiple myeloma with ISS staging were included for karyotyping, interphase nuclei fluorescence in situ hybridization (iFISH) and oligo-based array comparative genomic hybridization (oaCGH) analyses.

Results:

Clonal abnormalities were identified in 27% of analyses by karyotyping, in 83% by iFISH, and in 99% by oaCGH analysis. ISS staging combined with oaCGH aberrations identified ISS sub-groups.

Conclusion:

oaCGH analysis is a valuable asset in detecting prognostically relevant genomic abnormalities. The combination of oaCGH data with ISS staging might help define new sub-groups in multiple myeloma.