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Breast Cancer / Ovarian Cancer / Colon Cancer - Cancerous tumors in the immediate family |
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It is known nowadays that certain families experience an increased frequency of cancerous tumors.
In some cases, genes whose inheritance from generation to generation is responsible for an increased
risk of cancer have been identified.
In order to determine whether you belong to a high-risk group, the following points should be clarified.
If the answers to these questions are positive, it is advisable to refer to a genetic institute for
further tests.
- Are you yourself the patient, or is it a first or second-degree relative?
- Is it breast cancer, ovarian cancer or colon cancer?
- Was the tumor detected before the age of 45 - 50?
- Are there a number of patients in the family with cancerous lesions in addition to
those mentioned?
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Breast cancer and/or ovarian cancer |
The frequency of breast cancer and ovarian cancer in the population is relatively high, and in most cases (80%)
it is not hereditary, as far as is known today.
However, when breast cancer and/or ovarian cancer appears at a young age, the possibility that this is the genetic
form of the disease should be considered.
Two genes that predispose for breast cancer and ovarian cancer have been identified to date - these are
the BRCA1 and BRCA2 genes.
A woman with a mutation (genetic change) in one of these genes has a high risk of developing a
breast tumor (70%) and/or ovarian tumor (40%) during her lifetime.
The risk that the offspring of such a woman will inherit this mutation is 50%.
When a mutation is identified in the gene, such a person should be referred for counseling on how to
prevent the development of the tumor, methods of early diagnosis, and guidelines for appropriate follow-up.
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If you believe that your family is at risk, you should ask your physician to refer you to
a genetic institute that has an oncogenetic clinic where you will be able to obtain more details, to find
out whether testing is possible, which members of the family should be examined and when, etc.
In essence, multiple cases in the family, an early onset of cancer, the appearance of
cancer in both breasts or in a breast and an ovary in the same woman, represent the
main risk factors for the presence of the hereditary form.
It is important to note that genetic testing is not only relevant for knowing the degree of severity,
but also for practical and therapeutic purposes including the identification and prevention of tumors in the
future.
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For example, oophorectomy (removal of the ovaries) at the age of 40 significantly reduces the risk.
Specific guidelines for hormonal replacement therapy can be offered to carriers of mutations in these genes.
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Ovarian Cancer
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Colon cancer |
This is one of the most common tumors in adults.
The involvement of genetic factors in the development of these tumors was considered because of their
high frequency in certain families over a number of generations.
In all families with a genetic predisposition where tumors develop at a relatively young age, the
condition is transmitted by autosomal dominant inheritance.
More than 7 different genes are currently known to be associated with a genetic predisposition for
this cancer - some involve the formation of polyps in the intestine and some do not.
In most cases of these tumors, the APC gene on chromosome 5 is involved.
When a person inherits a mutation in this gene from one of his parents, another event must occur
where a mutation develops in the normal copy of the gene received from the other parent.
This is the first stage of tumor formation (polyp formation stage).
Mutations in other genes in the chain result in progressive degrees of malignancy.
In other words, inheriting a family mutation in the APC gene predisposes to the development of a
tumor, usually at an early age.
It is important to note that such tumors can be diagnosed early, allowing for early intervention
which can prevent deterioration to a stage of advanced malignancy.
In families who are predisposed to developing these tumors, if the mutation has been found in
certain family members, then mutation analysis should be offered to all the family members who are at risk.
This enables those individuals who do not have the mutation to avoid recurrent invasive tests, while
those who do have the mutation are advised to undergo frequent examinations so that if a tumor does
develop it can be diagnosed as early as possible in order that effective treatment can be commenced as
soon as possible.
There is another type of colon cancer that is sometimes associated with tumors in other organs of the body.
This type, which is known as HNPCC (Hereditary Non Polyposis Colon Carcinoma), is caused by certain specific
genes, not all of which are currently known.
This means that diagnosis of this type of colon cancer is more complicated than that of the type caused by
mutations in the APC gene.
It is recommended that all families at risk should be referred for genetic counseling in order to
determine the degree of risk, the specific gene or genes that might be associated with a genetic
predisposition (if any) in that family, the advantages and disadvantages of genetic testing, preventive
measures, monitoring, etc.
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Colon cancer symptoms and information
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