Research proves that not all DCIS patients need radiation therapy
Novel Signature Determines Recurrence Risk and Radiation Benefit for DCIS patients
DCIS patients and their doctors have been plagued with “what to do now?” Add radiation or not? What is the risk if they don’t? Research on a new biological signature published in Clinical Cancer Research (July 27, 2018) showed statistically significant results for determining both recurrence risk and radiation benefit.
When utilizing traditional clinical and pathologic parameters (size and grade) that determine the patient’s risk of recurrence (and deciding radiation benefit), the DCISionRT score reclassified ~50% of patients that would have been identified as “low risk” into the elevated risk category and 33% of patients considered traditionally “high risk” were reclassified as low risk.
DCISionRT identified a Low Risk Group with 10-year invasive breast cancer (IBC) risk of 4% and ipsilateral breast event - invasive+in situ – (IBE) risk of 7%
DCISionRT identified an Elevated Risk Group with IBC risk of 15% and IBE risk of 23%
More importantly, the DCISionRT was able to delineate if the patient would benefit from radiation.
The DCISionRT Low Risk Group received no significant benefit from radiation therapy
The DCISionRT Elevated Group received significant radiation therapy benefit with a relative risk reduction of ~70%
This study demonstrates that DCISionRT provides advances over currently available clinical, pathological and other tests for DCIS recurrence because of its ability to aid in the decision whether to radiate; leading to a better utilization of resources, decreased healthcare costs, decreased heart disease, and chest wall sarcomas.
It should be recognized however, that patient treatments were not randomized, stratified or standardized. Whether the patient received radiation or not was at the discretion of the physicians and patients.
In addition, patients in the study were only from two sites - University of Massachusetts-Worcester and Uppsala University-Sweden and may not be representative of the general population (i.e.: different genetic milieu). Lastly, approximately 25% of the patients received hormone therapy which can also affect invasive and in situ recurrence.
In summary, this paper is the first report of a genomic test for patients with DCIS that provides both prognostic information AND more importantly identifies patients who do and do not benefit from adjuvant radiation therapy.
We await the publishing of the DCISionRT results from the SweDCIS randomized clinical trial presented at the 2017 San Antonio Breast Cancer Symposium.