Study of Breast-Conserving Surgery Alone in Women Over 45 with Low-Risk DCIS Using Molecular and Clinical Factors

What this Trial Is About

Researchers are studying women with low-risk ductal carcinoma in situ DCIS to determine if breast radiation therapy can be safely avoided after breast conserving surgery. The study evaluates whether combining clinicopathological factors with the Oncotype DX DCIS score can identify those at very low risk of local recurrence. This prospective cohort study is conducted in Canada and aims to improve treatment decisions for women with DCIS. Participants will have their tumour tissue sent to Exact Sciences for DCIS score analysis. Those with a score predicting a 10-year local recurrence risk of 10% or less will be enrolled and followed without radiation therapy. The study will document surgery details, tumour characteristics, and patient health status using established criteria. Enrollment involves a two-step registration process through a web-based system. During the study, participants will be followed annually for up to 10 years with yearly breast exams and bilateral mammograms to monitor for recurrence. Data on patient demographics, tumour features, and outcomes will be collected and verified. The main outcome measured is the rate of local recurrence in the treated breast after five years, along with secondary measures such as invasive recurrence, disease-free survival, and overall survival.

Prospective Evaluation of Breast-Conserving Surgery Alone in Low-Risk Ductal Carcinoma in Situ (DCIS)