Familial Gastric Cancer Flashcards
(91 cards)
What are the major risk factors for developing gastric adenocarcinoma?
Heliobacter pylori infection
smoked/processed foods
obesity
alcohol/tobacco use
long-term inflammation
gastroesophageal reflux disease
What percentage of gastric adenocarcinoma cases have a familial predisposition?
Up to 10%.
How is “familial gastric cancer” defined?
Having two first- or second-degree relatives with gastric cancer diagnosed before age 50
or three first- or second-degree relatives diagnosed at any age.
Besides adenocarcinoma, what other types of gastric cancer exist?
Primary gastric lymphoma (2%–8%)
gastrointestinal stromal tumor (<1%)
neuroendocrine tumor (<1%)
What are the two histological subtypes of gastric adenocarcinoma according to the Lauren classification?
Intestinal and diffuse subtypes.
What is a key characteristic of the intestinal subtype of gastric adenocarcinoma?
Tumor cells are arranged in a glandular formation.
What are common associations with the intestinal subtype of gastric adenocarcinoma?
Environmental risk factors and a more favorable prognosis.
What distinguishes the diffuse subtype of gastric adenocarcinoma histologically?
Lack of adhesion molecules and poorly cohesive cells.
Why does the diffuse subtype of gastric adenocarcinoma have a poor prognosis?
It is highly metastatic, associated with transmural, poorly differentiated lesions, and is common in younger patients.
What percentage of all gastric cancers is accounted for by Hereditary Diffuse Gastric Cancer (HDGC)?
About 1% to 3%.
Which gene mutation is associated with HDGC, and where is it located?
A loss-of-function mutation in the CDH1 gene on chromosome 16q.
What is the role of the CDH1 gene, and how does its mutation contribute to cancer?
CDH1 encodes a cell-cell adhesion protein; loss of function increases invasiveness and promotes epithelial-to-mesenchymal transition
What types of cancer are individuals with a CDH1 mutation at higher risk of developing?
Diffuse, aggressive, signet ring gastric adenocarcinoma, and lobular breast carcinoma
or cleft lip and palate
What additional conditions are associated with CDH1 mutation in HDGC families?
Up to 60% of women may develop lobular breast cancer, and about 14% of families report cleft lip and palate.
At what age is CDH1 genetic testing recommended to begin, according to the IGCLC?
Testing is recommended to begin at 18 years of age.
When should asymptomatic family members with HDGC history consider genetic testing?
5 years before the earliest age of cancer diagnosis in the family or in their second decade of life.
Family Criteria (First- or Second-Degree Blood Relatives)
1
Individual Criteria
2
cont
3
At what average age do patients with Hereditary Diffuse Gastric Cancer (HDGC) typically develop poorly differentiated diffuse gastric cancer?
By around 38 years of age
Why is prophylactic total gastrectomy (PTG) recommended for asymptomatic CDH1 mutation carriers?
PTG offers excellent primary prevention outcomes against gastric cancer in HDGC patients.
What preoperative evaluations are essential before PTG in HDGC patients?
Nutritional assessment
discussion of surgical risks
and counseling on long-term dietary changes
What is the protocol for HDGC patients who decline PTG
Annual endoscopic surveillance starting at age 20
with multiple biopsies of visible lesions
and 30 random biopsies from all five stomach zones.
Why is endoscopic surveillance limited in detecting early diffuse gastric cancer in HDGC patients?
Diffuse gastric cancer can infiltrate the submucosa without visible lesions, resulting in a high false-negative rate.