Invasive ductal and lobular carcinoma and receptor status in the genetic context of breast cancer.

Invasive lobular carcinoma (ILC) represents about 10% of invasive breast cancers and is increasingly considered a unique disease entity. Certain genetic mutations predispose patients to ILC, as such this study aims to explore the ILC and IDC (invasive ductal carcinoma) in a genetic context. This is a retrospective chart review study. Any patient diagnosed with either ILC or IDC and a germline mutation with a predisposition for breast cancer is included in the study. Data was analyzed by patient's demographics, group stage, family history, and genetic mutation. Additionally, each tumor was analyzed for grade and receptor status. This study reviewed 372 patients of which 88.4% had IDC and 11.6% had ILC. Our results indicate that several variants in ATM, BRCA2, CDH1, CHEK2, EPCAM, PALB2, and PMS2 are more strongly associated with ILC - to varying degrees. [p < 0.001]. Additionally, ILC tumors kept several characteristics, even in the genetic context. ILC patients had a higher median age at presentation [p = 0.043], were more likely to have a lower grade compared to ductal tumors [p < 0.001]. and be estrogen receptor positive [p < 0.001] progesterone status positive [p < 0.001] and HER2 negative [p = 0.043]. ILC patients are more likely to have certain genetic mutations over others. This can help clinicians adapt when counseling these patients. Furthermore, ILC keeps its distinctive characteristics independent of the genetic backdrop.