The PREDICT Registry Australia: A Prospective Registry to Evaluate the Clinical Utility of a Biomarker Assay on Treatment Decisions in Patients with DCIS Following Breast Conserving Surgery

Abstract

<h3>Purpose/Objective(s)</h3> The benefit of adjuvant radiation therapy (RT) for women with ductal carcinoma in situ (DCIS) treated with breast conserving surgery (BCS) remains controversial. Although level-I evidence supports the role of RT in reducing the risk of local recurrence, the absolute benefit of RT is variable and so it is important to develop better prognostic and predictive tools. The assay under evaluation is a biologic signature that provides a validated decision score (DS) for assessing 10-year risk of recurrence and RT benefit using individual tumor biology as assessed by clinical and pathologic biomarkers. The primary objective of the PREDICT registries is to understand the decision impact such a tool has on treatment decisions. The hypothesis is that the biomarker assay is associated with changes in treatment recommendations for surgical, hormonal and/or radiation therapy. <h3>Materials/Methods</h3> This is a multi-center, prospective, observational study for women diagnosed with DCIS of the breast. After diagnosis, sites will send the most representative tissue block or sections for testing. Treating physicians complete a treatment recommendation survey before and after receiving test results. Test results, treatment recommendations, patient preferences and clinicopathologic features will be stored in a de-identified registry for participating institutions from a variety of geographic regions across Australia. Women will be followed for up to 10 years with completion of a follow-up form. The study includes females age 26 or older who are candidates for BCS and eligible for RT and/or systemic treatment. Subjects must not have been previously treated for DCIS or have previous or current invasive or micro-invasive breast cancer. The primary endpoints are changes in treatment recommendations for surgical, radiation and hormonal therapy. Secondary endpoints are identification of key drivers for treatment recommendations, including clinicopathologic factors and patient preference. Changes in pre- and post-test treatment recommendations will be analyzed using McNemar's test (alpha level = 0.05). Multivariate logistic regression will be used to determine odds ratios of clinicopathologic factors leading to pre- and post-test treatment recommendations. Pre-test covariates include patient age, tumor size, palpability, margin status, hormone receptor status, nuclear grade, tumor necrosis, family history, race, ethnicity and patient preference, as well as physician specialty and post-test covariates will also include the DS. Differences in recurrence-free and overall survival will be assessed by Kaplan-Meier survival analysis using the log-rank test and/or the Cox Proportional Hazards model. We are planning to enroll up to 1,500 women from up to 100 sites across Australia. A similar registry in the US has enrolled 2,500 women from 67 sites. <h3>Results</h3> TBD <h3>Conclusion</h3> TBD