Whether invasive lobular carcinoma (ILC) is genetic is complex. While most cases arise from somatic mutations (meaning they are not inherited), a smaller percentage of ILC cases are linked to inherited genetic mutations.
Here's a breakdown:
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Somatic Mutations (Not Inherited): The most common genetic alteration in ILC is a somatic mutation in the CDH1 gene. This mutation disrupts the production of E-cadherin, a protein that helps cells stick together. Because this mutation occurs in the cancer cells themselves and is not present in the patient's germline (eggs or sperm), it is not passed down to future generations. This is the most frequent scenario in ILC.
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Inherited Mutations (Familial): A smaller number of ILC cases are associated with inherited mutations in the CDH1 gene. These individuals inherit a faulty copy of the CDH1 gene from a parent. This inherited mutation increases their risk of developing not only ILC but also other cancers, most notably diffuse gastric cancer. This is part of Hereditary Diffuse Gastric Cancer syndrome (HDGC).
Therefore, while most ILC is not directly caused by inherited genes, a portion of cases are linked to familial CDH1 mutations. Genetic counseling and testing may be appropriate for individuals with a family history of ILC or diffuse gastric cancer.
