Prosigna Breast Cancer Prognostic Gene Signature Assay (formerly called the PAM50 test), is a genomic test for early-stage, hormone-receptor-positive breast cancer.
The Prosigna assay can only be used on breast cancers diagnosed in postmenopausal women that are:
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stage I or stage II and lymph node-negative
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stage II with one to three positive nodes
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hormone-receptor-positive
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invasive
Prosigna assay looks at the activity of 58 genes (called the PAM50 gene signature) to estimate the risk of distant recurrence.
Based on these activity levels, Prosigna assay results are reported as a risk of recurrence (ROR) score from 0 to 100 in two ways:
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node-negative cancers are classified as low (0-40), intermediate (41-60), or high (61-100) risk
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node-positive cancers are classified as low (0-40) or high (41-100) risk
Chemotherapy can be avoided in patients with low scores.