PROMISing answers for our intermediate risk Oncotypes.

We are all familiar with the use (and overuse) of the Oncotype Dx 21-gene assay in early stage breast cancer. As a reminder, this was generated way back in 2004 among the women randomized to Tamoxifen in the NASBP B-14 trial and prospectively validated in a similar cohort. This means its proven prognostic skilz strictly apply only to estrogen receptor (ER)-positive, HER2-negative, node-negative, T1-2 breast cancers treated with at least 5 years of Tamoxifen. What’s more, distant recurrences significantly differed only between the low and high risk cohorts. So what do we do with the 39% of patients with an intermediate (18-30) score?? Well, if 21 genes are good, 70 genes are even better--at least according to Agendia Inc. Last year’s MINDACT trial sells us an answer via the MammaPrint 70-gene assay, which provides a binary result of high or low risk only. MINDACT included a wider range of patients (21% node-positive, 10% HER2-positive, 10% triple negative) and basically showed, for patients to substantially benefit from adjuvant chemo, they have to be both clinically and genomically (per Mammaprint) high risk. The new PROMIS trial take a prospective look at 840 patients with known intermediate Oncotype DX scores and shows that over one-third had a change in chemo recs based on subsequent MammoPrint scores. The pub thus advocates for MammoPrint to be harnessed in the treatment decision-making for intermediate Oncotypes. The caveat: the authors of both MINDACT and PROMIS are on the Agendia Inc payroll. When it comes to genomic risk scores, we’ll let you do the math.