Detection of multicentric and contralateral breast cancers on MRI based on primary cancer biomarker status: will this change surgical or medical management?

Purpose: The utilization of staging preoperative breast MRI in biopsy-proven cancer patients varies based on institution and individual clinicians. It is unclear whether primary breast cancer subtype influences a clinician’s decision to obtain a preoperative breast MRI based on likelihood of multicentric or contralateral disease, which may change surgical or medical management. Our purpose was to compare the four main breast cancer subtypes in our patient population (i.e., luminal A, luminal B, HER2 enriched and triple-negative) who underwent pretreatment staging MRIs to determine whether certain breast cancer subtypes are more likely to have multicentric or contralateral disease. Methods: We retrospectively reviewed 435 patients with biopsy-proven invasive breast cancer who had staging MRI. Results: Of these patients, 14 had biopsy-proven multicentric disease (3.2% of total) and 15 had biopsy-proven contralateral second tumor sites (3.4% of total). There was no statistically significant difference between primary tumor subtype and likelihood of multicentric or contralateral disease (p = 0.3065). Conclusion: Pretreatment staging MRI can detect multicentric and/or contralateral additional tumor sites, which ultimately changes staging, treatment options, and outcomes for patients with biopsy-proven breast cancer. There is no correlation between primary breast cancer subtype and likelihood of multicentric or contralateral disease.