Prophylactic nipple-sparing mastectomy for CHEK2 mutation: a case report

Checkpoint Kinase 2 (CHEK2) *1100delC is a rare genetic mutation that confers an elevated lifetime risk of breast cancer that increases with each afflicted family member. This variant may be found in 1.1% of breast cancer patients, or up to 2.9% of breast cancer patients with Northeastern European heritage. Given a lifetime risk that ranges from 20–44%, patients with CHEK2*1100delC may consider the option of bilateral prophylactic mastectomy. We describe the case of a 35-year-old female with a strong family history of breast cancer who tested positive for the CHEK2*1100delC mutation. The patient opted to undergo bilateral prophylactic nipple-sparing mastectomy with temporary tissue expander placement and breast reconstruction 6 months later. The patient continues to report a good post-operative outcome six years after her bilateral mastectomy. To our knowledge, no case reports describing prophylactic mastectomy for CHEK2 mutation have been published. Due to a lifetime risk of breast cancer approaching that of other well-studied mutations, patients with CHEK2*1100delC should be offered the option of bilateral prophylactic mastectomy with extensive discussion of risks, benefits, alternatives, cosmetic outcome, and psychosocial consequences. So far, no clear survival benefit has been identified in patients who have undergone prophylactic mastectomy compared to routine surveillance. However, patients may benefit from improved breast and psychosocial well-being, as prophylactic mastectomy can reduce the risk of breast cancer by more than 90%. Depending on the experience and expertise of the clinician, both skin or nipplesparing mastectomy may be considered as they have equivalent outcomes.