Prosigna^®

Prosigna^® simultaneously measures the expression levels of 46 genes used for the intrinsic subtype classification algorithm2, 8 housekeeping genes used for signal normalisation, 6 positive controls, and 8 negative controls in a single hybridization reaction using nucleic acid probes designed specifically to those genes.

The algorithm reports a Risk of Recurrence (ROR) score on a 0–100 scale. This is correlated with the probability of distant recurrence at ten years for post-menopausal women with hormone receptor-positive, early-stage breast cancer.

The Risk of Recurrence (ROR) is reported in two ways:

1. node-negative cancers are classified as low (0-40), intermediate (41-60), or high (61-100) risk
2. node-positive cancers are classified as low (0-15), intermediate (16-40), or high (41-100) risk

The ROR score is calculated using coefficients from a Cox model that includes the Pearson correlation to a 46-gene subset of the 50 genes used to calculate each intrinsic subtype, a proliferation score, and tumour size.

The test variables are multiplied by the corresponding coefficients from the Cox model to generate the score, which is then adjusted to a 0–100 scale based on coefficients generated from the training set of FFPE breast tumour samples. Risk categories are also reported based on cut-offs for ROR determined in a clinical validation study.

A personalised report, which is sent to the customer’s clinician, will include:

• Intrinsic Subtype identified
• Risk of Recurrence (ROR) within 10 years
• Risk of Recurrence (ROR) 5-10 years (late relapse)
• Clinicopathological factors, such as tumour size and nodal status incorporated in the score

Who can order this test from Everything Genetic? Healthcare providers

Turnaround time: 10 working days from receipt of the tumour sample in laboratory.

Preferred specimen collection:

• Tissue input format: Macro-dissected 10-micron-thick slide- mounted tissue sections
  Minimum tumour size: 4 mm² tumour area
  Minimum tumour cellularity: 30% within tumour area

Alternative specimen collection: None

Billing information: Prosigna^® is reimbursed for NHS patients and by private medical insurance providers (CCSD code 6005G).

Delivery information: Test kits will be sent out by using a Royal Mail Tracked service, unless otherwise arranged.

Prosigna^® measures the gene expression profile using RNA extracted from Formalin-Fixed, Paraffin-Embedded (FFPE) breast tumour tissue. The gene expression data are weighted together with clinical variables to generate both a subtype (luminal A, luminal B, Her2-enriched, or basal-like) and a score indicative of the probability of distant recurrence of disease. The assay is performed on the NanoString nCounter® Dx Analysis System using FFPE breast tumour tissue previously diagnosed as invasive breast carcinoma.

A pathologist examines a hematoxylin and eosin (H&E) stained slide and identifies (and marks) the area of invasive breast carcinoma suitable for the test. The pathologist also measures the tumour surface area, which determines the number of unstained slides required for the test, and the tumour cellularity to ensure the presence of sufficient tumour tissue for the test. A trained technician macrodissects the area on the unstained slides corresponding to the marked tumour area on the H&E- stained slide and isolates RNA from the tissue. The isolated RNA is then tested on the NanoString nCounter Dx Analysis System to provide test results including the Prosigna® Score and risk category.

Assay and technical information

Prosigna^® in conjunction with the nCounter^® Dx Analysis System, is CE marked for in vitro diagnostic use in patients with Hormone Receptor-Positive (HR+), lymph node-negative, Stage I or II breast cancer and patients with Hormone Receptor- Positive (HR+), lymph node positive, Stage II & IIIA breast cancer to be treated with adjuvant endocrine therapy.

Validations and papers

View all validation documents and papers for this genetic test here >>