Combining Multiomics and Histological Assessment to Identify PDX Models of Invasive Lobular Carcinoma

Breast cancer is primarily of no special histologic subtype (NST), with invasive lobular carcinoma (ILC) being the most common special subtype, accounting for 10-15% of cases. ILC is the 6th most common cancer in women and is characterized by the loss of E-cadherin (CDH1), leading to unique growth patterns that make it harder to detect early. Despite better short-term prognostic factors than NST, ILC patients have poorer long-term outcomes, which are not fully understood. This under-studied subtype lacks sufficient research models, hindering progress in understanding its biology and testing therapies.

• ILC represents 10-15% of breast cancers, with around 40,000 new cases in the US in 2022.

• Loss of E-cadherin causes a distinct single-file growth pattern in ILC, complicating early detection and treatment.

• There is a critical need for more in vitro and in vivo models, such as ILC PDX and PDXO, to improve understanding and therapy development.