Carry on.

Should you worry about an increased risk of second malignancy in women with germline BRCA-mutations receiving breast radiation? Their cells have only one copy of BRCA, which plays an important role in DNA repair, so some wonder if those cells are more susceptible to DNA damage that could result in later cancer. In this cohort of 230 BRCA-mutation carriers treated with breast radiation over a 20 year period, 6 developed secondary malignancies, 1 of which was in technically in the radiation treatment field—a papillary thyroid cancer diagnosed 17 years post-radiation [insert unimpressed emoji]. In other words, there were no in-field sarcoma or skin cancers over more than 3K person-years. TBL: The incidence of in-field secondary malignancy among BRCA-mutation carriers receiving breast radiation is 0.32/1000 person-years (i.e., tiny and no greater than in other populations). | Schlosser, Int J Radiat Oncol Biol Phys 2020