Prognostic tests

Genomic testing of tumour tissue is available to determine the risk of recurrence (ROR) and benefit of chemotherapy for individual patients or to identify tumour mutations that may be targetable by new or off-label therapies. Tests can be ordered by a GP or SMO.

When available, gene expression test ROR scores can be incorporated into the calculation of breast cancer stage (American Joint Committee on Cancer AJCC Cancer Staging System 8^th Edition staging).

Mammaprint is available for stage 1 or 2, ER+/-, HER2- breast cancer with 0-3 positive lymph nodes. The test provides a risk score for distant recurrence after hormone therapy, from low (10%) to high (29%). It is used to determine whether a patient would benefit from the addition of chemotherapy.

Oncotype DX is recommended for cancers that will be treated with hormone therapy. It is available for stage 1 or 2, ER+/HER2- breast cancer with either no lymph node involvement or 0-3 positive lymph nodes. It is a molecular diagnostic test that predicts the likelihood of a patient's tumour recurring over a ten-year period and whether any benefit is gained by adding chemotherapy to hormone therapy. It analyses 21 genes in the tumour and develops a three-tier recurrence score between 0 and 100.

If the recurrence score is:

• <18: There is a low risk of recurrence. The benefit of chemotherapy treatment is likely to be small and outweighed by the risk of side effects.
• 18-30: There is an intermediate risk of recurrence and it's not clear whether the chemotherapy benefits are greater than the risks of side effects.
• ≥31: There is a high risk of recurrence and the benefits of chemotherapy are likely to be greater than the risks of side effects.

There is also an Oncotype DX test to predict recurrence of DCIS.

EndoPredict is suitable for those who have ER+, HER- breast cancer, where the cancer hasn’t spread to the lymph nodes. Those who have fewer than three lymph nodes affected may also be able to take the test. It is used to predict 10-year risk of distant recurrence and the benefit a patient will receive from chemotherapy. It analyses 12 genes within a tumour sample and gives an EPclin Risk score to determine whether patients have a ‘low’ or ‘high’ risk of recurrence.

ProSigna is available for postmenopausal women with early-stage (stages I, II and IIIA), HR+, node+/- breast cancer that will be treated with hormone therapy. The test categorises tumours by molecular subtype – Luminal A, Luminal B, HER2 enriched and Triple Negative. It then looks at expression of 50 genes and combines these results to provide a 10-year risk of recurrence score – either low, medium or high.

Foundation One extracts DNA from tumour or blood samples to identify the unique genomic code of the tumour, to investigate gene mutations currently known to be involved in cancer. The genomic alterations in the tumour are then used to identify potential avenues of treatment, such as targeted therapies, clinical trials or treatment approved for another tumour type. The test is designed to analyse any type of solid tumour, including advanced breast cancer.

A patient’s Foundation One profile may propose therapies that are not funded and / or not available in New Zealand, either commercially or via clinical trial. It is recommended that the patient discusses proposed therapies with their medical team.