McGuiness tested positive for the BRCA1 genetic mutation when she was 25, which meant she had a high risk of developing breast cancer, she told BuzzFeed Life. She was getting screened every six months and decided to get a preventative bilateral mastectomy when she was 30, even earlier than the doctors suggested.
On the last MRI before her surgery, they found something. The biopsy results came back with stage 1 ductal breast cancer (ER/PR positive, HER2 negative, grade 3). "In a strange way it was comforting," said McGuinness. "I didn't have to question if I was making the right choice by removing them."