A Study of Clinical Outcomes for the NanoString® Technologies Prosigna™ Gene Signature Assay

The secondary objectives will consist of:

• The evaluation of the confidence in the therapeutic indications of the practitioners before and after the test (assay) results, and by subgroups of cancers
• The evaluation of the rate of secondary effects of chemotherapy,
• The evaluation of the emotional state of patients faced with the therapeutic decision, of their degree of anxiety and of their functional status before and after the Prosigna test (assay) results

Inclusion criteria

• Resected node-negative, estrogen-receptor-positive, HER2-negative early- stage invasive breast cancer (T1-T2, N0, pN0 (i+), pN0 (mol+), M0)

• Estrogen receptor status will be evaluated by Immunohistochemistry (IHC) and more than 1% of stained tumor cells will be considered positive.
• HER2 status will be evaluated by IHC (0 or 1+, or 2+ will be considered negative) and by in-situ fluorescence hybridization.
• Postmenopausal women defined as:

• Natural Amenorrhea > 12 months, regardless of age
• Bilateral oophorectomy, regardless of age (the oophorectomy must have been carried out at least 4 weeks before entering the study)
• Radiological castration with amenorrhea > 3 months, regardless of age
• Hysterectomy and postmenopausal blood levels
• Able to give consent
• Eligible for treatment of breast cancer with adjuvant chemotherapy
• ECOG performance status of 0 or 1

Exclusion criteria

• Tumor size T3-T4
• Non-invasive breast cancer (e.g., Paget's disease, DCIS)
• Tumors with nodes that are not N0, pN0 (i+), or pN0 (mol+)
• Tumors that are estrogen-receptor negative or HER2 positive
• Have metastatic disease
• Unable to give informed consent
• Unable to complete patient reported outcome surveys
• Have contraindications for adjuvant chemotherapy

• Age, performance status, significant comorbidities
• ECOG performance status > 1