Correlation between family history and characteristics of breast cancer.

Family history is a major risk factor for breast cancer; approximately 5-10% cases of breast cancer are associated with a family history. Herein, we investigated the link between family history and breast cancer features to elucidate the importance of family history in the diagnosis and treatment of breast cancer. Data from 10,549 patients with breast cancer were collected from 2014 to 2017. Detailed information about the family history of the patients including the degree and number of relatives affected and the types of cancer was recorded. The tumors were pathologically and clinically classified based on the stage, grade, ER, PR, HER2, Ki-67 status, and subtypes, according to standard guidelines. Data were analyzed using χ2 test and multiple logistic regression. Patients with a family history of other cancer types were significantly older at diagnosis than patients with a family history of breast/ovarian cancer (p = 0.002) and those without a family history of cancer (p < 0.001). Patients without a family history of cancer were typically diagnosed at a later stage, including high frequency in N2 (p = 0.035) and TNM stage III (p = 0.015). Compared with patients with second-/third-degree relatives, those with first-degree relatives having breast/ovarian cancer had a higher median age (54.1, p < 0.001) at diagnosis and showed more advanced disease. No significant difference was found between ER, PR, and HER2 status in patients with and without a family history of cancer. Family history of breast cancer can influence the cancer characteristics of the patients at diagnosis, especially patient age, tumor stage, and grade.