New Data and Society Guidelines Support Value of Oncotype DX Breast Recurrence Score Test in Guiding Neoadjuvant Treatment Decisions for Newly Diagnosed Patients

• Study results presented at ASCO20 showed that the Recurrence Score results on core biopsies predict the likelihood of response to neoadjuvant chemotherapy
• Results are particularly relevant in the context of the Covid-19 pandemic which is causing the delay of elective surgeries across health systems worldwide

Exact Sciences Corp. today announced results from three studies of the Oncotype DX Breast Recurrence Score test, presented at the virtual 2020 American Society of Clinical Oncology (ASCO) Annual Meeting. The findings highlight the value the Oncotype DX test can provide by personalising and improving neoadjuvant treatment decisions (i.e., prior to surgery) in women with hormone receptor positive, HER2-negative breast cancer.

“As health systems across the world respond to the Covid-19 pandemic, decisions are being made that are resulting in the postponement of both screening and diagnostic oncology services as well as elective surgery,” said Dr Emilio Alba, Director of the Medical Oncology Units at the Hospital Universitario Virgen de la Victoria in Malaga, Spain. “This new evidence shows that the Oncotype DX test may be used to inform neoadjuvant therapy while awaiting surgery, therefore helping us to overcome some of the unique challenges we are currently facing in managing breast cancer patients.”

One study1 presented at ASCO20 included 76 women treated with neoadjuvant chemotherapy from the Young Women’s Breast Cancer Study, a multi-center prospective group of women diagnosed with breast cancer at age 40 or younger. The Oncotype DX test was performed on tumor specimens from core biopsies obtained from the patients prior to surgery. Results revealed that patients with a higher Recurrence Score result were more likely to achieve a pathologic complete response (pCR; no residual invasive tumour) with chemotherapy. Most pathologic complete responses were achieved in patients with a Recurrence Score result of 26 and above. In contrast, only two patients with a Recurrence Score of 0-25 achieved pCR, and both had results between 21-25. These findings are consistent with previously published neoadjuvant studies in older breast cancer patients.

A second study2 was conducted in Spain and prospectively analysed a group of 63 patients who received neoadjuvant chemotherapy after the Oncotype DX test was performed on tumour specimens from core biopsies. The analysis also showed a strong correlation between pCR and Recurrence Score result. In particular, the Recurrence Score result was the most significant predictor of pCR when compared to other factors such as Ki67 (a classic prognostic factor), estrogen receptor status and initial tumour size. None of the patients with a Recurrence Score result of 0-25 achieved a pCR.

In the third study3 , the Oncotype DX test was performed prior to surgery and patients with Recurrence Score results 0-30 received neoadjuvant endocrine therapy without chemotherapy. After four months of treatment, data from 142 patients showed that 97% of them had a clinical response or stable disease, suggesting that patients with a Recurrence Score result

The new data presented at ASCO20 add to existing evidence4,5,6 and reinforce the value of the Oncotype DX test in light of recent Covid-19 pandemic recommendations.7,8 Core biopsy specimens represent 14% of the overall Oncotype DX Breast Recurrence Score test volume, and they have a testing success rate of more than 98%.9