While inherited mutations—such as mismatch repair gene mutations in Lynch syndrome, TP53 gene in Li–Fraumeni syndrome, and APC gene in familial adenomatous polyposis—increase susceptibility to multiple malignancies [4, 5], breast cancer is not typically associated with HNPCC, and our patient did not meet the Amsterdam II criteria for Lynch syndrome. Here, TP53 is linked to breast carcinoma.