Cate's Story: Hereditary Diffuse Gastric Cancer

Area of Science:

• Oncology
• Genetics
• Cancer Research

Background:

• Gastric cancer is a leading cause of cancer mortality globally, accounting for approximately 10% of all cancer deaths.
• Hereditary diffuse gastric cancer (HDGC) represents a small but significant subset of gastric cancers, driven by inherited genetic factors.
• HDGC is an autosomal dominant disorder necessitating early detection and intervention strategies.

Observation:

• The primary genetic driver of HDGC is a germline mutation in the CDH1 gene, also known as E-cadherin.
• Individuals with a CDH1 mutation have an estimated 80% lifetime risk of developing diffuse gastric cancer.
• Females carrying CDH1 mutations also face a substantially elevated risk of lobular breast cancer, with a cumulative risk reaching 60% by age 80.

Findings:

• Germline CDH1 mutations are definitively linked to hereditary diffuse gastric cancer.
• The penetrance of gastric cancer in carriers is high, emphasizing the hereditary nature of the disease.
• A significant comorbidity of lobular breast cancer exists in female carriers of CDH1 mutations.

Implications:

• Genetic screening for CDH1 mutations is crucial for families with a history of HDGC.
• Prophylactic measures and increased surveillance are recommended for individuals identified with CDH1 mutations.
• Understanding the dual risk of gastric and breast cancer in HDGC necessitates comprehensive screening protocols for affected individuals and families.