What GIS score indicates HRD positivity?

What GIS score indicates HRD positivity?

• A. 16 or higher
• B. 30 or higher
• C. 50 or higher
• D. 42 or higher

Answer: (D)

The key idea is the threshold used to call HRD positive based on the Genomic Instability Score. GIS is a composite measure of chromosomal instability reflecting homologous recombination repair deficiency. In the widely used myChoice HRD assay, a GIS of 42 or higher designates HRD positivity. This cutoff comes from validation studies showing tumors with GIS ≥ 42 tend to have HRD and respond to PARP inhibitors. The other numeric options are not the established cutoff for HRD positivity in this context.

The key idea is the threshold used to call HRD positive based on the Genomic Instability Score. GIS is a composite measure of chromosomal instability reflecting homologous recombination repair deficiency. In the widely used myChoice HRD assay, a GIS of 42 or higher designates HRD positivity. This cutoff comes from validation studies showing tumors with GIS ≥ 42 tend to have HRD and respond to PARP inhibitors. The other numeric options are not the established cutoff for HRD positivity in this context.