Gynecology. Oncological diseases, signs

In the article "Gynecology oncological diseases signs" you will find very useful information for yourself. In most cases, cancer occurs as a result of sporadic mutation of a single cell. However, in some cases, cancer is associated with a genetic mutation and can be inherited from generation to generation.

Oncological diseases are extremely common all over the world. At present, the theory is widely recognized that cancer has genetic aspects, and its immediate cause is often a genetic mutation (DNA damage) that causes disruption of the cell's vital activity.

Sporadic mutations

Fortunately, most (up to 70%) of these mutations are sporadic, i.e. occur in a single cell of the body. Sex cells (oocytes and spermatozoa) are not affected, which excludes the risk of inheriting cancer. The cause of most of these mutations is unknown, but environmental factors that damage the cell's DNA, such as cigarette smoke, have been identified. Only 5-10% of cancerous diseases are recognized as genetically determined. This means that the risk of disease with these forms of cancer can be inherited. They are the consequence of the inheritance of the mutation of the so-called genes of predisposition to cancer.

Genetic mutation

In the human body, there are genes that control the vital activity of the cell. In case of mutation, cancer can develop. Pathology can occur in any cell of the body, including ovules or spermatozoa (mutation of germinal germ cells). Thus, a mutation can be passed on to succeeding generations. With such mutations, the nature of inheritance is usually well traced.

Family Cases of Cancer

Approximately 20% of cancers can be considered family. This means that within the same family there are several cases of cancer without a clear character of inheritance. In such cases, the disease can be a consequence:

There may also be a combination of several factors, such as the inheritance of certain genes that make an individual more susceptible to the influence of environmental factors. In the human body, there are two copies of each gene that are inherited one from each of the parents. If one of the parents has one copy of the mutant cancer predisposition gene, the probability of transmission to the offspring is 50%. Thus, the risk of developing cancer is not always inherited.

Genetic inheritance

The inheritance of a single copy of a mutant gene predisposing to cancer does not always lead to a disease. This is because the cell is able to function normally with a second normal copy of the gene inherited from the other parent. However, if in this cell the mutation of the only normal copy ever occurs, it can give rise to the development of a cancerous tumor. In most cases, the cause of the second mutation is unknown.

The risk of developing cancer

The probability of cancer development due to the inheritance of mutation of the gene of predisposition to cancer is denoted by the term "penetrance". It is rarely 100%. This means that an individual who inherits a defective gene does not necessarily fall ill with cancer, as this requires a mutation and a second copy of the gene. Some genes of predisposition to cancer can cause multiple tumors in one family, such as in breast and ovarian cancer. Other genes are associated with an increased risk of cancer on the background of other, non-malignant diseases. For example, a disease such as neurofibromatosis, is accompanied by an increased likelihood of cancer of the nervous system. The main complaints are associated with epileptic syndrome and the presence of benign nodules on the skin.

Risk assessment

The risk of developing cancer associated with the inheritance of genes predisposing to cancer depends on the type of defective gene and its penetrance. In assessing the degree of risk, three main factors are taken into account: the probability of hereditary conditionality of the family form of cancer. Depends on the number of cases and the form of cancer that is characteristic of this family, as well as the age at which the disease has occurred; probability that this family member inherited a mutant gene. Depends on his position in the pedigree, age, the presence of a malignant tumor; the likelihood of developing cancer if the gene is inherited; is determined by its penetrance. In the risk assessment, a combination of these factors is taken into account. Often the results are difficult to state in a form that is accessible to the patient. There is no single right way to tell him about the risk of developing cancer - the approach should be individual. Most often, the degree of risk is represented as a percentage or as a 1: X ratio. The value obtained is compared with the risk in the general population. The management of patients - carriers of genes predispositions to cancer depends, mainly, on the degree of risk of development of cancer. It is evaluated with the help of special analyzes in the process of genetic counseling. Hereditary predisposition to cancerous tumors in the family can be detected under various circumstances, for example, if one of her members is concerned about the growing number of cases of cancer in relatives and seeking advice from a specialist. Members of families with a high incidence of cancer tend to develop malignant tumors at a younger age. Moreover, the incidence of morbidity within the family may be higher than in the population.

Cancer in children

For most family cancer syndromes, the onset of the disease is uncommon in childhood, except for some extremely rare pathologies, such as multiple endocrine neoplasia-H (MEN-H) syndrome.

Standards of hospitalization

At present, it is not possible to carry out surveillance at the genetic center for all patients who have cases of cancer in the family. Therefore, it is important that these medical institutions comply with the hospitalization standards. The genetic center also provides management of patients at increased risk of developing cancer, but not high enough to receive referral to a specialist. The task of genetic counseling is to provide patients with accessible information about the patterns of development of malignant tumors.

Genetic centers

In the clinic, doctors are able to assess the inherited predisposition and the risk of developing cancer, provide the patient with information on the inheritance of genes predisposing them to risk reduction and genetic testing. It is important to explain to the patient that not all cases of family cancer are associated with the inheritance of a known gene of predisposition - many of them have not been identified to date. Risk assessment Risk of cancer may be a problem in reporting a high risk of cancer. This must be done in such a way as not to cause the patient excessive anxiety. It can also be difficult to explain to the patient that the cancer risk is lower than he assumed. For example, there is a misconception that the daughter of a patient with breast cancer is a group at increased risk for this disease. If the case of a mother's disease is unique in the family and the tumor has appeared after menopause, the risk of developing breast cancer is not higher than in the population. The management plan for the patient or the whole family depends on the final results of the evaluation of the probability of inheritance of a mutant cancer predisposition gene and the associated risk of developing a malignant tumor.

There are four areas of management of such patients (the first two can also be used in cases of moderate risk):

Preventive measures

Patients with an extremely high risk of hereditary cancer syndrome in addition to screening and lifestyle changes are assigned genetic analysis, and a number of preventive measures. These may include prophylactic mastectomy (removal of the mammary glands) and oophorectomy (removal of the ovaries) in carriers of the BRCA1 / 2 gene and colectomy (removal of the large intestine) in carriers of the FAP gene to prevent the development of cancer of these organs in the future. To detect mutations of some genes predispositions to cancer, it is possible to conduct a special blood test. Mutations often affect the entire gene completely, and for different families a wide variety of variants of genetic mutations is characteristic. In certain ethnic groups there is a tendency to bear a certain mutation. Before genetic testing is offered to all family members, it is necessary to identify the type of family mutation. For this, a blood test is primarily carried out by a family member who is already cancer-affected. Once the type of family mutation is determined, it is possible to conduct a genetic analysis for all other relatives. Unfortunately, it often happens that some members of a family with cancer are no longer alive and it is not possible to carry out a genetic test. In this case, the management of the rest of the family is limited to assessing the likelihood of mutation inheritance.

Results of genetic analysis

Genetic testing should be carried out only with the full genetic counseling, in the process of which resumes the results and gives time for reflection. The consultations discuss the social and individual significance of positive or negative test results. A positive result can have negative psychological consequences for both the tested person and his family members. It can also lead to negative social consequences, such as the inability to insure one's life or find a job.

Genetic testing in children

Children are not always encouraged to use genetic testing to identify genes associated with the possibility of developing cancer in adulthood. The study is conducted only in the event that its result can affect the management of the patient, for example, in the MEN-PA syndrome. In such cases, carriers of the mutant gene are offered thyroidectomy at the age of 5 to 15 years, which completely excludes the development of medullary thyroid cancer.