“It was an important part of my treatment”: a qualitative study of Norwegian breast Cancer patients’ experiences with mainstreamed genetic testing oleh Nina Strømsvik, Pernilla Olsson, Berit Gravdehaug, Hilde Lurås, Ellen Schlichting, Kjersti Jørgensen, Teresia Wangensteen, Tone Vamre, Cecilie Heramb, Lovise Mæhle, Eli Marie Grindedal