Radiation is widely used in medical imaging diagnosis and irradiation therapy, leveraging its penetrating and ionizing capabilities. It has also proven beneficial in cancer treatment. However, the risk of cancer development due to radiation-induced cellular damage is recognized as a stochastic effect. Consequently, radiation is administered with care in medical settings, especially in cases involving hereditary diseases where repairing cell damage poses significant challenges. BRCA1/2 genes exhibit high penetrance in breast, ovarian, prostate, and pancreatic cancers, known for promoting tumors through autosomal dominant inheritance, adult-onset, multiple cancer types, and deficiencies in homologous recombination repair. Concerning breast-conserving surgery with radiation and radiation exposure during imaging and potential secondary cancer risks, the stochastic effects of radiation on individuals carrying germline BRCA1/2 mutations in a single-allele remain inconclusive. Therefore, it is important to continue accumulating and accurately interpreting evidence to determine appropriate risk management methods for each patient based on the cancer susceptibility of BRCA1/2 mutation carriers. This process should consider medical evidence, the patient’s age, cosmetic appearance, cost-effectiveness, and patient’s satisfaction.