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Clinical Evidence in Neoadjuvant Setting

Clinical Highlights | TransNEOS Study | WSG ADAPT Trial | Neoadjuvant Chemotherapy

Why use the Oncotype DX Breast Recurrence Score® test in the neoadjuvant setting?

Neoadjuvant therapy administered before surgery may:

  • Improve the likelihood of successful breast-conserving surgery through tumor shrinkage1
  • Downstage the nodal status in the axilla1
  • Help assess primary tumor response to systemic therapy1

To help patients reach these outcomes, the Breast Recurrence Score® test is a proven predictor of response to neoadjuvant treatment among postmenopausal women with node-negative breast cancer and provides useful information to help guide systemic treatment decisions2-6:

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Patients with lower Recurrence Score® (RS) results experienced greater clinical responses from neoadjuvant hormonal therapy compared to patients with higher Recurrence Score results.

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Patients with higher Recurrence Score results experienced greater clinical and pathologic responses from neoadjuvant chemotherapy compared to patients with lower Recurrence Score results.

TransNEOS study: neoadjuvant endocrine therapy and Oncotype DX® test6

Patients in the TransNEOS study (a translational study of New Primary Endocrine-therapy Origination Study [NEOS]) had tumors ≥2 cm and archived core-biopsy samples taken before neoadjuvant letrozole and subsequently were sent for Breast Recurrence Score testing. A total of 295 patients were included in TransNEOS.

 

 STUDY ENDPOINTS

Primary: Evaluate clinical (complete or partial) response to neoadjuvant letrozole for Recurrence Score results <18 vs Recurrence Score results ≥31

Secondary: Evaluate clinical response and rate of breast-conserving surgery by continuous Recurrence Score test result


The Recurrence Score result group, which compared patients with Recurrence Score results 0-17 to patients with Recurrence Score results 31-100, was significantly associated with the rate of clinical response (χ2 test, P<0.001).

Even when including patients with Recurrence Score results of 18-30, the Recurrence Score result group remained significantly associated with the rate of clinical response (Cochran–Armitage trend test, P<0.001).


The Recurrence Score result group was not associated with breast-conserving surgery candidacy before neoadjuvant letrozole but was significantly associated with breast-conserving surgery received after treatment (table to the right).

Among patients with Recurrence Score results 0-17, pretreatment surgery recommendation significantly differed from posttreatment surgery received (McNemar’s test, P<0.001), whereas there was no significant change among patients with Recurrence Score results 31-100 (P=0.075).

STUDY CONCLUSIONS

The authors concluded that the TransNEOS study validates the Recurrence Score result as a significant predictor of clinical response to neoadjuvant letrozole in postmenopausal women with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-), clinically node-negative breast cancer.

  • Patients with Recurrence Score results 0-17 were significantly more likely than patients with Recurrence Score results 31-100 to respond to neoadjuvant letrozole and undergo breast-conserving surgery
  • Patients with Recurrence Score results 0-17 may be candidates for neoadjuvant endocrine therapy to elicit a clinical response and conversion from mastectomy to lumpectomy

WSG ADAPT trial: neoadjuvant chemotherapy studies with the Oncotype DX test7

The West German Study Group adjuvant dynamic marker-adjusted personalized therapy (WSG ADAPT) hormone receptor-positive (HR+)/HER2– trial used clinicopathological features, Recurrence Score result (static biomarker), and Ki-67 levels after a short course of preoperative endocrine therapy to assign treatment for patients with HR+, HER2- invasive breast cancer.

Patients received either adjuvant endocrine therapy or chemotherapy (either in the adjuvant or neoadjuvant setting) followed by adjuvant endocrine therapy. For patients who were cN0-1, assignment to chemotherapy was based on one of the following findings: Recurrence Score results 12-25 and Ki-67post-ET >10% or Recurrence Score results 26-100. Of the 2,241 eligible women assigned chemotherapy in the trial, a total of 864 (including 582 with evaluable Recurrence Score results) received their chemotherapy in the neoadjuvant setting.

 STUDY CONCLUSIONS

The authors concluded that among patients with Recurrence Score results, the rate of pathological complete response (pCR) was significantly higher in the group with Recurrence Score results 26-100 than in the group with Recurrence Score results 12-25.7

A predictor of response to neoadjuvant chemotherapy

The National Cancer Database was used to identify all patients with T1-T3, ER+, HER2- primary breast cancer from 2010 to 2015 who had the Breast Recurrence Score test performed and received neoadjuvant chemotherapy (N=989). Recurrence Score results were strongly associated with the likelihood of pathologic complete response.8

Distribution by RS Group:

  • RS 0-17:   23.0%
  • RS 18-30:  45.5%
  • RS 31-100:  31.5%

RS=Recurrence Score result.

In a similar manner, the National Cancer Database was used to identify all patients with T1-T2, clinically N1/N2, ER+, HER2- invasive ductal carcinoma of the breast from 2010 to 2015 who had the Breast Recurrence Score test performed and received neoadjuvant chemotherapy (N=158). Recurrence Score results were significantly associated with the likelihood of pCR in the axilla.9

Distribution by RS Group:

  • RS 0-17:   35.4%
  • RS 18-30:  39.2%
  • RS 31-100:  25.3%

RS=Recurrence Score result.

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