Locoregional recurrence risk
A significant association was observed in studies between the Recurrence Score® (RS) result and the risk for locoregional recurrence (LRR), in both node-negative and node-positive patients.1,2 The results of these studies have potential clinical implications for locoregional therapy decisions for patients with node-negative or node-positive estrogen receptor-positive (ER+) breast cancer.1-3
In node-negative patients with ER+ tumors treated with either placebo (n=355), tamoxifen (n=895), or chemotherapy plus tamoxifen (n=424), the Recurrence Score result was an independent, significant predictor of LRR along with age and type of initial treatment.1
NSABP=National Surgical Adjuvant Breast and Bowel Project.
In node-positive patients who had ER+ tumors, the Recurrence Score result was an independent predictor of LRR along with number of positive nodes. LRR varies widely by Recurrence Score result in patients with 4 or more positive nodes. Thus, the Recurrence Score result provides critical information on LRR risk in women with 4 or more positive nodes.2
*Treatment also included adjuvant chemotherapy and tamoxifen in patients with ER+ or progesterone receptor-positive (PR+) disease.
Recurrence Score result and use of radiation with mastectomy
In postmenopausal women with node-positive, ER+ breast cancer treated with mastectomy without radiation therapy, LRR was low when the woman had 1-3 positive nodes and a Recurrence Score result <18.4
Recurrence Score result and use of radiation with mastectomy
In women with 1-3 positive nodes and Recurrence Score results ≤25, RNI appeared to show no benefit vs no RNI.3 Premenopausal and postmenopausal patients with 1-3 positive nodes and Recurrence Score results ≤25 were treated with breast-conserving surgery (BCS) plus radiation therapy with or without RNI. All patients also received either endocrine therapy alone or chemoendocrine therapy. LRR (cumulative incidence at 5 years) was low regardless of whether RNI was given:
- 0.85% in patients with BCS, radiation therapy, and RNI
- 0.55% in patients receiving BCS and radiation therapy only
Late recurrence risk
One of the challenges facing physicians is identifying which patients are at higher risk of distant recurrence after 5 years of hormone therapy.
The Oncotype DX Breast Recurrence Score® test may identify patients who are at higher risk of distant recurrence beyond 5 years and might have greater benefit from extended hormonal therapy.5
- The landmark NSABP B-14 study shows the association between quantitative ER expression and tamoxifen benefit6:
- Patients with Recurrence Score results ≥18 were at a higher risk of late recurrence (5-10 years) than patients with Recurrence Score results <185
- The NSABP B-28 study shows that patients with Recurrence Score results ≥18 and a higher quantitative ER expression (>9.1) had an increased risk of late distant recurrence (5-10 years)5
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