CDH1 Mutation Invasive Lobular Breast Carcinoma

The purpose of this study is to evaluate the safety and tolerability of talectrectinib as treatment for Stage IV ILC with CDH1 mutation

This trial collects information about factors that affect communication of genetic test results, decision-making, and access to genetic testing in women with hereditary gynecological cancers. Studying individuals who are positive for a genetic mutation and immediate biological family members (including a parent, full-sibling, or child) may help identify cancer genes and other persons at risk.

Invasive lobular breast carcinoma (ILBC) represents 5-15% of all invasive BCs. The CDH1 gene (OMIM no. 192090), located on the chromosome 16q22.1, encodes for the E-cadherin protein, a key regulator of cell adhesion. Loss of E-cadherin expression is frequently detected in LBC CDH1 germline loss-of-function mutations are associated with the autosomal dominant cancer-predisposition syndrome, hereditary diffuse gastric cancer (HDGC; OMIM no. 137215). The cumulative risk of LBC for women with a CDH1 mutation is estimated to be 42% (95% CI 23% to 68%) by 80 years, when it is a component of HDGC syndrome.
Recently, some authors described CDH1 germline mutations in women with in situ or ILBC with early onset (<45 or <50) and bilateral in situ or ILBC with no family history of HDGC. These results are opening a new scenario, suggesting that CDH1 could be a susceptibility gene for LBC in women without a family history of DGC.
The first aim of this study is to investigate prevalence of CDH1 in this specific population of women with early onset (<45 or <50) in situ or ILBC, bilateral LBC or LBC with no family history of HDGC.