I have the nasty CHEK2 gene and have had prostate and breast cancer. Both treated at MN Mayo Clinic. Prostate with 20 proton beam radiation treatments and mastectomy and 3 positive nodes removed and 16 proton beam radiation. I have been taking tamoxifen for almost 3 years and am 84. Just had a 3-year f/u colonoscopy with 2 benign polyps removed. I play bridge, exercise and wash/wax my car while living in an active sr. living facility. No more house/yard chores! My internist checks my thyroid twice/year. This gene is frightening, but I decided that the mind over matter issue was controllable. Took awhile. Be well and decrease your anxiety by not playing "what if." We walk in each other's shoes. Educate your docs about this horrible gene!!