- Hereditary diffuse gastric cancer
- Criteria for the diagnosis of hereditary diffuse gastric cancer
- What do you need to know when deciding to undergo a genetic test for stomach cancer?
- Indications for a genetic test for the presence of a mutation in the CDH1 gene
- A gene mutation is not a sentence - prophylaxis reducing the risk of stomach cancer
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In Poland, about 6.5 thousand jobs are recorded annually. cases of stomach cancer. The cause of about 20 percent of cancers is probably a hereditary predisposition. To confirm this assumption, it is necessary to perform a genetic test. In the case of a family predisposition to diffuse gastric cancer, the confirmation is the detection of a mutation in the E-cadherin (CDH1) gene.
Probably each of us met with a family in which more than one person suffered from cancer, as well as with a family in which no cancer has been reported. Therefore, it is difficult not to draw a conclusion about the family predisposition to neoplastic diseases, which is close to the statement about their heredity.
Hereditary diffuse gastric cancer
Stomach cancer is one of the most common cancers of the gastrointestinal tract, its incidence is estimated at 1: 5,000. - 1: 10 thousand In Poland, about 6.5 thousand are diagnosed annually. cases ofstomach cancer . Familial aggregation of neoplasms is observed in approx. 20% of all diagnosed cases, i.e. more than one cancer incidence in a close family. In such a situation, we can assume that the diseases are not accidental, and that their causes are genetic predispositions. To confirm this assumption, it is necessary to performgenetic test . In the case of a family predisposition to diffuse gastric cancer, the confirmation is the detection of a mutation in the E-cadherin (CDH1) gene on chromosome 16q22 (mainly numerous point mutations).
Identifying mutations in the CDH1 gene, for both sexes, is associated with a risk of up to 80%of diffuse gastric cancer . Additionally, in mutation carriers the risk of developing lobular breast cancer increases up to 60%.
Hereditary Diffuse Gastric Cancer (HDGC) occurs at a very young age, most often occurs before the age of 40, and cancer is known to occur as early as 14 years of age.
Criteria for the diagnosis of hereditary diffuse gastric cancer
1) Having a diffuse gastric cancer in two first or second degree relatives when at least one of them was diagnosed with cancer before the age of 50.
2) The diffuse form of cancer occurred in three 1st or 2nd degree relatives,regardless of the age of these people.
What do you need to know when deciding to undergo a genetic test for stomach cancer?
The most important thing before performing the test is contact with a specialist - a geneticist who will make us aware of what the obtained genetic test result means for our future life.
Our genetic material does not change throughout life, the obtained result is also the same. Knowing about being a carrier of a mutation that drastically increases the risk of developing cancer can significantly affect the psyche of the person who underwent the test, as well as their family - that is why a specialist genetic consultation is so important.
Indications for a genetic test for the presence of a mutation in the CDH1 gene
1) Family history of gastric cancers (at least 2-3), especially those diagnosed before the age of 50.
2) Family history of diffuse gastric cancer associated with lobular breast cancer, especially after excluding BRCA2 mutations.
3) A family history of atypical cases of diffuse gastric cancer (before 40 years of age, gastric cancer and lobular breast cancer in one person, gastric cancer and cleft lip / palate).
4) When detecting a CDH1 gene mutation in a relative with diffuse gastric cancer, it is advisable to test all asymptomatic relatives (and in some families also before 18 years of age) who may be carriers of the mutation. Carrier testing of the CDH1 gene mutation allows the determination or exclusion of a high individual risk among he althy relatives of mutation carriers.
A gene mutation is not a sentence - prophylaxis reducing the risk of stomach cancer
For people with confirmed CDH1 mutations, prophylactic measures are recommended, such as:
1) Gastroscopy at least once a year, starting about 5-10 years earlier than the earliest illness in the family. Due to the high risk of diffuse gastric cancer and the limited effectiveness of the available preventive tests, the treatment of choice recommended for carriers of the E-cadherin gene mutation isprophylactic gastric resection . However, the operation should be planned individually for each mutation carrier, because both the average age of onset and the degree of gastric cancer invasiveness show large variations in individual families with the detected mutation.
2) In loaded familiescolonoscopyevery 3-5 years from the age of 40.
3) Additionally, in mutation carriers, imaging breast examinations every 12 months, at least from the age of 35.
In order to reduce the risk of disease carriers, there is an absolutesmoking ban . It is also recommended to useappropriate dietie: eliminate foods containing nitrates and nitrites (smoked, pickled, s alted), and enrich the diet with a large amount of vegetables and fruits (vitamin C, antioxidants).
Remember that having a mutation in the CDH1 gene is not a sentence, it is information about a higher than population susceptibility to HDGC. Information that allows for the early application of preventive measures, reducing the risk of developing the disease and / or helping in the early detection and treatment of cancer.