The Impact of the Gene Recurrence Score on Chemotherapy Prescribing in ER Positive, Lymph Node Positive Early Stage Breast Cancer
The Impact of the Gene Recurrence Score on Chemotherapy Prescribing in ER Positive, Lymph Node Positive Early Stage Breast Cancer
This study examines the impact of an additional tumour test called the 21 gene Recurrence
 Score (OncotypeDx®), a commercially available test on a Medical Oncologist's decision to
 recommend chemotherapy.
After a breast cancer and any lymph glands have been surgically removed, further (adjuvant)
 treatment is generally given to reduce the risk of cancer recurrence. For patients with
 estrogen receptor (ER) positive breast cancer, this treatment has traditionally been
 chemotherapy and hormone therapy. However, it is increasingly recognised that tumours which
 are ER positive and negative for the human epidermal growth factor receptor 2 (HER2), are
 relatively resistant to chemotherapy. It is likely that many more people are exposed to the
 risks for chemotherapy than ever benefit from it. In order to select patients who will get
 more benefit from chemotherapy and to spare those who get very little benefit from side
 effects, risk assessment tools are being developed.

 The 21 Gene Recurrence Score is a test that examines the tumour genes to estimate the risk of
 the tumour relapsing and possible chemotherapy benefits. Currently, the 21 Gene Recurrence
 Score (OncotypeDx®) is used In Ireland for patients with no cancer in their lymph nodes. For
 these patients it can help in deciding who should get chemotherapy. Patients with low scores
 can sometimes avoid chemotherapy. In some countries, this test is offered to almost all
 patients with ER positive breast cancer, irrespective of whether the cancer has spread to
 lymph nodes or not. However, in Ireland this test is not standardly available for patients
 who have breast cancer involving lymph nodes.
Inclusion Criteria:

 General Inclusion Criteria (All Patients)

 1. Age 18 years of age or older

 2. ER Positive Tumours (≥1% positive cells or Allred score ≥ 2 (Appendix 1))

 3. Human Epidermal Growth Factor Receptor 2 (HER2) negative breast cancer (0-1 by IHC or
 FISH <2.0)

 4. No evidence of metastatic disease on CT, bone scan or other imaging

 5. Fit for consideration of chemotherapy as determined by the Investigator

 6. Adequate performance status (Eastern Cooperative Oncology Group (ECOG) 0 or 1
 (Appendix 2))

 Inclusion Criteria - Cohort 1 (Postoperative Patients): N= 75

 1. Adequate surgical excision of breast tumour (mastectomy or lumpectomy) and lymph nodes
 (sentinel lymph biopsy or axillary dissection)

 2. Any tumour size (T stage (Appendix 3))

 3. Involvement of 1-3 lymph nodes (N1, including micrometastases)

 Inclusion Criteria - Cohort 2 (Preoperative Patients): N= 75

 1. Candidates for preoperative therapy for early breast cancer

 2. T2-T4 tumours

 3. Involvement of at least one lymph node, (including micrometastases) on biopsy

 4. Adequate tissue from core biopsy for 21 gene RS testing (approximate minimum 5mm)

 Exclusion Criteria (All patients):

 1. ER negative tumour (Allred score 0-1)

 2. HER2 positive tumours as defined by IHC 3+ or FISH ≥ 2.0

 3. Node negative disease, including those with Isolated tumour cells only (node negative
 i+/i-)

 4. Known metastatic breast cancer

 5. Performance status ≥ 2

 6. Patients not considered by their treating physician to be fit to undergo chemotherapy.

 7. Men with breast cancer.