Is there an association between invasive lobular carcinoma of the breast and a family history of gastric cancer?

CDH1 gene mutations have been found to be associated with diffuse type gastric cancer and invasive lobular carcinoma (ILC) of the breast. To the best of our knowledge, this is the only study relating a family history of gastric cancer to ILC of the breast. We conducted a retrospective study comparing the family history of malignancies in patients with invasive ductal carcinoma (IDC) of the breast and ILC treated in our Medical Center. The comparison was evaluated in both types of breast cancer groups, dividing the patients into two age groups, <50 and ≥50 years. One thousand one hundred and sixty-seven patients with IDC and ILC entered the study. A family history of malignancies was reported in 21.6 % of patients with IDC as opposed to 37.8 % of patients with ILC (P < 0.001). A history of gastric cancer was reported in 7.2 % in the ILC group as compared to 2.3 % in the IDC group, P < 0.008. A family history of breast cancer was more common in the ILC group as opposed to the IDC group, 18 versus 8.1 % respectively, P = 0.002 and persisted in both age groups. We conclude that a family history of malignancies in first degree relatives is more common in patients with ILC than IDC and that there is a significant association between a family history of gastric cancer and ILC.