PreludeDx™ Achieves New Milestones for DCIS Patients and DCISionRT® Testing

LAGUNA HILLS, Calif., June 12, 2026 /PRNewswire/ -- Prelude Corporation (PreludeDx™), a leader in precision diagnostics for breast cancer, today highlighted a new milestone for DCISionRT®, its validated genomic test that provides individualized recurrence risk assessment and predicts radiation therapy benefit for women diagnosed with ductal carcinoma in situ (DCIS).

Approximately 60,000 women are diagnosed with DCIS in the United States each year. As physicians increasingly seek personalized approaches to treatment planning, utilization of DCISionRT continues to expand across academic and community cancer centers nationwide.

PreludeDx recently reached a significant milestone, with more than 3,000 breast cancer physicians ordering the DCISionRT test for over 45,000 patients, reflecting broad adoption across the breast cancer care community. Since its clinical launch in 2017, utilization of DCISionRT has grown exponentially as clinicians increasingly incorporate personalized risk assessment into treatment planning for patients with DCIS. Currently one in three DCIS patients undergoing breast conserving surgery in the United States utilize DCISionRT to better inform shared decision-making – a testament to the test's growing role in improving patient care.

The growth in adoption has been accompanied by an expanding body of clinical evidence supporting the use of DCISionRT. In the large published multicenter PREDICT study involving 2,007 patients treated at 63 academic and community centers, DCISionRT results changed radiation therapy recommendations in 38% of cases. The study also demonstrated that the DCISionRT result was the most influential factor driving physician treatment recommendations, highlighting the test's impact on real-world clinical decision-making and utilization.

Further clinical evidence supporting that DCISionRT provided significant information beyond clinical pathologic (CP) factors, nomograms and criteria was recently published. DOI: 10.1016/j.ijrobp.2025.07.1411

Dr. Atif Khan, co-author and Director, Breast Radiotherapy Services, Memorial Sloan Kettering Cancer Center stated, "This observational study further supports optimizing de-escalation and escalation treatment strategies using DCISionRT." Dr. Khan continued, "Over 50% of patients in the study initially classified low-risk by CP criteria were actually High Risk, based on their molecular tumor biology assessed by DCISionRT. These reclassified patients had significant benefit from radiation therapy."

Recent milestones further supporting the clinical utility of DCISionRT include FDA Breakthrough Device designation and CMS Advanced Diagnostic Laboratory Test (ADLT) status. These recognitions reinforce the test's role in helping physicians personalize treatment decisions and reduce both overtreatment and undertreatment among women diagnosed with DCIS.

"Over the past several years, we have seen growing recognition that women diagnosed with DCIS benefit from individualized treatment strategies," said Dan Forche, President and CEO of PreludeDx. "DCISionRT annual patient utilization will continue to increase in 2026, along with the number of physicians ordering the test. More than one in three newly diagnosed DCIS patients treated with breast conserving surgery are currently receiving DCISionRT testing. The significant growth in both physician adoption and test utilization reflects increasing confidence in the clinical value of biologically informed, personalized treatment decisions."

DCISionRT has been clinically validated across multiple peer-reviewed studies and has demonstrated the ability to identify patients who are most likely to benefit from radiation therapy while helping others avoid unnecessary treatment. As evidence continues to expand and adoption grows, DCISionRT is increasingly being incorporated into routine treatment planning discussions, supporting more informed and personalized care for women diagnosed with DCIS.

About DCISionRT®

DCISionRT is a clinically validated biologic risk signature that combines molecular biomarkers with clinicopathologic factors to provide individualized recurrence risk assessment and predict radiation therapy benefit for patients diagnosed with ductal carcinoma in situ (DCIS). The test is designed to support shared decision-making between physicians and patients by providing personalized information that can help guide treatment planning following breast-conserving surgery.

About PreludeDx

PreludeDx is a leading personalized breast cancer diagnostics company serving patients and physicians worldwide. Founded in 2009 with technology from the University of California San Francisco, PreludeDx is dedicated to developing precision breast cancer tools that impact treatment decisions. The company's mission is to provide innovative technologies that improve patient outcomes and reduce healthcare costs.

Before making a treatment decision, Know Your Risk™, Know Your Benefit.

For more information on how PreludeDx is making a difference for patients, please visit the Company's website: https://preludedx.com and follow us on X, LinkedIn, Instagram and Facebook.

Media Contact
Martin Sandgren
Klover Communications
press@klovercommunications.com

Investor Contact
Andrew Wade
PreludeDx
awade@preludedx.com

SOURCE Prelude Corporation