Gene Expression Assay May Guide Ductal Carcinoma In-Situ Management

A 12-gene expression assay has yielded “encouraging results” in the ECOG-ACRIN E4112 trial (NCT02352883), and support potentially guiding treatment decision-making for patients with breast cancer with ductal carcinoma in situ (DCIS) score estimates, according to Seema A. Khan, MD.

In a conversation with CancerNetwork^®, Khan, a professor of surgery in the Surgical Oncology Division of Feinberg School of Medicine at Northwestern University, discussed the rationale for assessing an assay’s feasibility in helping identify patients who may be eligible to omit radiotherapy following MRI-guided surgery based on a potential correlation between the genetic expression of their DCIS lesion and the risk of recurrent disease. She stated that the DCIS scores may be a reasonable consideration for guiding whether patients should receive radiation, although she suggested that additional trials are necessary to further evaluate the assay’s predictive ability.

Khan presented these findings at the 2023 San Antonio Breast Cancer Symposium (SABCS).

Transcript:

Our group, ECOG, started a trial a while ago in the 1990s where [patients] with what was considered to be known as DCIS were advised to not receive radiotherapy. Those results led to the present trial—the one that we’re reporting today. During the development of that 1990s trial, there was a biological assay that was developed that measured the expression of 12 genes; that’s now called the DCIS score. In the E4112 trial that we’re reporting, part of our strategy was to use the DCIS score to advise [patients] whether their risk of disease recurrence in the breast was low enough that they could avoid radiation. On the other hand, [we would] advise [patients] with higher DCIS risk scores to receive radiation because their risk of invasive recurrence was higher.

The takeaway message at the moment is that these are encouraging results for the use of molecular assays to guide [treatment]. Patients who are given advice based on real information about the assay, according to these results, do follow that advice. So far, the predictive performance of these assays is working out as expected. If there are open trials available, that’s always the best course; that will give us more answers. But in clinical practice, the use of this DCIS score in the manner that we used it in this trial is a reasonable consideration and should be offered to patients with an adequate explanation of what we know and what we don’t know.

Reference

Khan S, Romanoff J, Gatsonis C, et al. Magnetic resonance imaging and a 12-gene expression assay to optimize local therapy for ductal carcinoma in situ: 5-year clinical outcomes of ECOG-ACRIN 4112. Presented at the 2023 San Antonio Breast Cancer Symposium; December 5-9, 2023; San Antonio, TX; abstract GS03-01.