IRIS: Risk-Based Imaging After Breast-Conserving Surgery

Breast cancer follow-up after curative treatment is currently based on largely uniform imaging surveillance strategies, despite substantial variation in recurrence risk across patient subgroups. Early detection of recurrences improves prognosis, particularly when detected by imaging rather than symptoms, but the optimal surveillance approach remains uncertain. Mammographic sensitivity is lower in breast cancer survivors than in screening populations, and interval cancers occur more frequently, especially among younger patients, those with dense breasts, aggressive tumor subtypes, or without radiotherapy after breast-conserving surgery.

This multicenter, open-label, register-based randomized controlled trial evaluates risk-stratified imaging surveillance after breast-conserving surgery for breast cancer. The study investigates whether more sensitive imaging methods, compared with standard mammographic follow-up, lead to earlier detection of ipsilateral recurrences and contralateral second primary breast cancers in patients at increased risk of recurrence.

The primary endpoint is the number of interval ipsilateral recurrences and contralateral second primary breast cancers detected within five years from index diagnosis. Secondary endpoints include stage at detection, breast cancer-specific survival, overall survival, recall rate, biopsy rate, false positive findings, and health-related quality of life.