Co-incidence of ductal breast cancer and gastrointestinal cancers: A case-series study

Hereditary cancer syndromes are defined as genetic disorders that increase the risk of developing certain types of cancers. The increased risk of breast cancer (BC) is well-established in association with the majority types of these syndromes. Previous studies have reported the co-incidence of gastrointestinal cancers accompanied by BC in various types of hereditary cancer syndromes like hereditary breast and ovarian cancer syndrome (HBOC), Peutz-Jeghers syndrome (PJS) and Cowden syndrome (CS). Although clinical data have confirmed the simultaneous occurrence of lobular BC and gastrointestinal cancers in some families, to the best of our knowledge there is no report on the co-incidence of ductal BC and gastrointestinal tumors in inherited syndromes. In the present study, we report BC in patients who were affected by ductal ones from two large pedigrees in which gastrointestinal malignancies have been reported previously. Our observation of these two uncommon phenotypes at the same time recommends refining clinical guidelines that are merely based on phenotypes.