How would you manage a premenopausal patient with HER-2 positive DCIS in the setting of a prior HER-2 positive contralateral breast cancer?  

The patient had a prior right-sided ER+ HER2-ve breast cancer, treated with neoadjuvant chemotherapy, MRM with ALND, and PMRT

They recently developed contralateral left-sided DCIS that was accidentally checked for HER2 and found to be positive (3+)

Would your management of the patient's DCIS differ based on their prior contralateral breast cancer diagnosis or HER-2 positivity?



Answer from: Radiation Oncologist at Academic Institution