Breast Cancer / Ovarian Cancer / Colon Cancer - Cancerous tumors in the immediate
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?
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.
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.
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.
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
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.
Colon cancer symptoms and information