Having both ATM & CHEK-2 mutations

jumpstart

Hi this is my first post - seems like a super helpful community! I have a strong family history of breast cancer and recently got my genetic test results back after a breast cancer diagnosis in September (age 41). I was found to have both ATM and Chek-2 mutations (ATM c.3214G>T and CHEK2 c.470T>C). The genetic counsellor said it was quite rare to have both mutations together, and that risk of a new cancer would likely be about 30-40%. I live outside of the US where protocols are a bit different and have found it difficult to get clear advice and guidance from my breast surgeon or oncologist about whether prophylactic BMX and/or oophorectomy (no family history of ovarian cancer but have highly ER+ ILC) would be indicated. They have basically said I could have BMX if I want to - or just have more frequent screening, without recommending any particular course of action.

I had a lumpectomy in October before getting genetics results (I knew BRCA wasn’t a factor), and am currently undergoing chemo (T-AC) and have been told I will have radiation after. I am also quite concerned about risks of contralateral cancer after radiation, especially having 2 gene mutations that affect DNA repair - but oncologist doesn’t seem concerned and said even if I had BMX he would still recommend radiation as I was lymph node positive.

I was just wondering if anyone else had any experiences they could share of having these gene mutations together, and/or what advice has been given in terms of prophylactic BMX, oophorectomy, and radiation treatment with these mutations (separately or together). I am feeling a bit lost. I have read whatever relevant scientific study I can get my hands on - but would be really helpful to hear of some personal experiences on these topics.

Thanks in advance!

Linda