The benefits of a model of interval comprehensive assessments (MICA) in hereditary cancer Syndromes: Hereditary diffuse gastric cancer (HDGC) as an example

Abstract

A high percentage of individuals at risk for hereditary cancer syndromes are unaware of their risk. This is especially detrimental in syndromes such as hereditary diffuse gastric cancer due to a CDH1 germline mutation, for which lifesaving prevention is possible. Surveillance for diffuse gastric cancer in the syndrome is limited, hence the recommendation for prophylactic total gastrectomy for mutation carriers. Genetic counseling and testing is crucial in suspected families but initial contact could be limited, leading to the importance of an interval comprehensive review every 5-8 years to identify and screen additional high-risk individuals. Our contact with a hereditary diffuse gastric cancer family in Jordan in 2011 led to a number of family members receiving education and genetic counseling. Our model of interval comprehensive assessment (MICA) was constructed and implemented by conducting family information service, video call and emails to the high-risk individuals 7 years after initial contact. Using an updated family pedigree we reached out to an additional thirteen high-risk members in six different countries and provided them with genetic education, counseling, and testing. Six members agreed to CDH1 testing (46%). Four tested positive (66%) and one member (25%) underwent prophylactic total gastrectomy.

Keywords: CDH1; Genetic counseling; Genetic testing; Hereditary cancer; Hereditary diffuse gastric cancer; Lobular breast cancer.