FES-PET in the Treatment of Patients with Breast Cancer: Clinical Case 2

Jeremy Force, DO: For case No. 2, we have a 60-year-old female with, again, hormone-positive, HER2 [human epidermal growth factor receptor 2]-negative metastatic breast cancer. She had received adjuvant dose-dense AC [doxorubicin, cyclophosphamide], weekly paclitaxel for a T2 N2 grade 2 invasive ductal carcinoma. This was about 8 years ago. She subsequently completed 5 years of an aromatase inhibitor about 3 years ago. Then she came into my clinic complaining of lower back pain. We obtained a PET [positron emission tomography]/CT scan showing that there was what appeared to be oligorecurrent metastatic breast cancer. This was the only lesion that was identified in her vertebrae.

If you see here, it is FES [F-18 fluoroestradiol]-positive. The uptake for this was not complete, meaning that there was some tumor heterogeneity. We biopsied this area, and it was ER+ [estrogen receptor-positive], PR- [progesterone receptor-negative], HER2-negative breast cancer. We discussed it with our spine metastasis tumor board. SBRT [stereotactic body radiation therapy] was applied in her situation. Then she was initiated on a different CDK4/6 inhibitor with a selective estrogen receptor degrader. We had to dose reduce the CDK4/6 inhibition by 1 dose reduction. She has had no evidence of gross disease for over a year.

Transcript Edited for Clarity