DCISionRT Decision Score Predicts the Need of Radiation Therapy for Treating Ductal Carcinoma in Situ

Breast-conserving surgery and adjuvant radiotherapy have long been the mainstay for treating ductal carcinoma in situ (DCIS). For years, researchers have sought to understand which group of patients with DCIS actually benefit from radiation therapy and which could forgo this treatment. Using the DCISionRT® assay, researchers have cracked the code with results from the PREDICT trial demonstrating the clinical impact.

Using a seven-gene biosignature, clinicians are able to provide their patients with a potential benefit from radiation therapy, as well as predicting the 10-year rates of breast recurrence with and without radiation therapy. Having this clinically validated decision score may change the way clinicians and patients make treatment decisions.

Background

Roughly 60,000 women in the U.S. are diagnosed with DCIS each year. “The outcomes for patients diagnosed with DCIS are very good,” says Chirag Shah, MD, Co-Director of the Comprehensive Breast Program and Director of Breast Radiation Oncology at Cleveland Clinic Cancer Institute. “One of our goals is to maintain those excellent outcomes while de-intensifying treatment so that patients aren’t unnecessarily put at risk of radiation therapy side effects.”

One of the challenges is that there has been no effective way to predict which patients need radiation therapy to prevent recurrences and which do not. Researchers have attempted to use clinical and pathologic factors to determine which patients need radiation therapy, but those studies have failed to identify a group of patients that do or do not benefit from radiation therapy with respect to recurrence in the breast.

In recent years, researchers have focused on new assays that provide patients with specific information about their risk of recurrence and potential benefits of radiation therapy. One of these – DCISionRT – has consistently identified a low-risk group that does not benefit from radiation therapy with respect to local control, while also identifying an elevated risk group that does benefit from radiation therapy.

Study details

The PREDICT study intended to identify how the DCISionRT score impacts recommendations for radiation therapy. 2,496 women receiving treatment across 60 academic and community hospitals were enrolled in the study between February 2019 and January 2022. DCISionRT was used as part of each patient’s care plan. Physicians reported treatment recommendations before and after the DCISionRT score.

Study results

The DCISionRT score changed radiation therapy recommendations 38% of the time. This resulted in a net 20% decrease in recommendations for radiation therapy. Also, in 42% of women who would typically be considered low risk for recurrence by clinical and pathologic criteria, the DCISionRT score led to a recommendation to proceed with radiation therapy. “The strongest influence on the final recommendation for radiation was the DCISionRT score, with patient preference being the second most important factor,” says Dr. Shah. “We’re learning that the best thing we can do for patients is provide a tool like this that allows for enhanced shared decision-making and informed discussions.”

What’s next

Cleveland Clinic Cancer Institute was involved with the enrollment of patients on the PREDICT trial and publication of data from the randomized SweDCIS trial that validated these findings.

Based on these studies, the DCISionRT test may prove beneficial for preventing over- and under-treatment of patients with DCIS. The researchers are undertaking numerous studies to identify how the DCISionRT assay compares to other approaches of risk stratifying patients with DCIS. Cleveland Clinic will also be opening the PREDICT II trial, which will further study physician treatment recommendations and the role of the DCISionRT assay.