- Despite accounting for about 15% of all BCs diagnosed each year, making ILC the second most common histologic subtype after invasive ductal breast cancer (IDC), it is largely underrepresented in genetic studies.
- Pathogenic alteration frequencies were compared between female ILC and IDC cases, among ~91,000 patients referred for testing, including ~4700 ILC cases
- Pathogenic alterations were more common in CDH1 in ILC patients while BRCA1 and PALB2 were more common in IDC patients. Other than that, gene-specific pathogenic alterations were similar between ILC and IDC cases referred for MGPT, supporting multigene panel testing when suspecting hereditary cancer predisposition regardless of an ILC vs. IDC diagnosis.