Fluorescent in situ hybridization (FISH). FISH - a study for differential diagnosis Fish analysis in breast cancer

Head of
"Oncogenetics"

Zhusina
Julia Gennadievna

Graduated from the Pediatric Faculty of the Voronezh State Medical University. N.N. Burdenko in 2014.

2015 - internship in therapy on the basis of the Department of Faculty Therapy of the Voronezh State Medical University. N.N. Burdenko.

2015 - certification course in the specialty "Hematology" on the basis of the Hematological Research Center in Moscow.

2015-2016 – therapist of the VGKBSMP No. 1.

2016 - the topic of the dissertation for the degree of candidate of medical sciences "study of the clinical course of the disease and prognosis in patients with chronic obstructive pulmonary disease with anemic syndrome" was approved. Co-author of more than 10 publications. Participant of scientific and practical conferences on genetics and oncology.

2017 - advanced training course on the topic: "interpretation of the results of genetic studies in patients with hereditary diseases."

Since 2017 residency in the specialty "Genetics" on the basis of RMANPO.

Head of
"Genetics"

Kanivets
Ilya Vyacheslavovich

Kanivets Ilya Vyacheslavovich, geneticist, candidate of medical sciences, head of the genetics department of the medical genetic center Genomed. Assistant of the Department of Medical Genetics of the Russian Medical Academy of Continuous Professional Education.

He graduated from the Faculty of Medicine of the Moscow State University of Medicine and Dentistry in 2009, and in 2011 - residency in the specialty "Genetics" at the Department of Medical Genetics of the same university. In 2017 he defended his thesis for the degree of Candidate of Medical Sciences on the topic: Molecular diagnosis of copy number variations of DNA segments (CNVs) in children with congenital malformations, phenotype anomalies and/or mental retardation using SNP high-density oligonucleotide microarrays»

From 2011-2017 he worked as a geneticist at the Children's Clinical Hospital. N.F. Filatov, scientific advisory department of the Federal State Budgetary Scientific Institution "Medical Genetic Research Center". From 2014 to the present, he has been in charge of the genetics department of the MHC Genomed.

Main areas of activity: diagnosis and management of patients with hereditary diseases and congenital malformations, epilepsy, medical genetic counseling of families in which a child was born with a hereditary pathology or malformations, prenatal diagnostics. During the consultation, an analysis of clinical data and genealogy is carried out to determine the clinical hypothesis and the required amount of genetic testing. Based on the results of the survey, the data are interpreted and the information received is explained to the consultants.

He is one of the founders of the School of Genetics project. Regularly makes presentations at conferences. He lectures for geneticists, neurologists and obstetricians-gynecologists, as well as for parents of patients with hereditary diseases. He is the author and co-author of more than 20 articles and reviews in Russian and foreign journals.

The area of ​​professional interests is the introduction of modern genome-wide studies into clinical practice, the interpretation of their results.

Reception time: Wed, Fri 16-19

Head of
"Neurology"

Sharkov
Artem Alekseevich

Sharkov Artyom Alekseevich– neurologist, epileptologist

In 2012, he studied under the international program “Oriental medicine” at Daegu Haanu University in South Korea.

Since 2012 - participation in the organization of the database and algorithm for the interpretation of xGenCloud genetic tests (https://www.xgencloud.com/, Project Manager - Igor Ugarov)

In 2013 he graduated from the Pediatric Faculty of the Russian National Research Medical University named after N.I. Pirogov.

From 2013 to 2015 he studied in clinical residency in neurology at the Federal State Budget Scientific Institution "Scientific Center of Neurology".

Since 2015, he has been working as a neurologist, researcher at the Scientific Research Clinical Institute of Pediatrics named after Academician Yu.E. Veltishchev GBOU VPO RNIMU them. N.I. Pirogov. He also works as a neurologist and a doctor in the laboratory of video-EEG monitoring in the clinics of the Center for Epileptology and Neurology named after A.I. A.A. Ghazaryan” and “Epilepsy Center”.

In 2015, he studied in Italy at the school "2nd International Residential Course on Drug Resistant Epilepsies, ILAE, 2015".

In 2015, advanced training - "Clinical and molecular genetics for practicing physicians", RCCH, RUSNANO.

In 2016, advanced training - "Fundamentals of Molecular Genetics" under the guidance of bioinformatics, Ph.D. Konovalova F.A.

Since 2016 - the head of the neurological direction of the laboratory "Genomed".

In 2016, he studied in Italy at the school "San Servolo international advanced course: Brain Exploration and Epilepsy Surger, ILAE, 2016".

In 2016, advanced training - "Innovative genetic technologies for doctors", "Institute of Laboratory Medicine".

In 2017 - the school "NGS in Medical Genetics 2017", Moscow State Scientific Center

Currently, he is conducting scientific research in the field of epilepsy genetics under the guidance of Professor, MD. Belousova E.D. and professor, d.m.s. Dadali E.L.

The topic of the dissertation for the degree of Candidate of Medical Sciences "Clinical and genetic characteristics of monogenic variants of early epileptic encephalopathies" was approved.

The main areas of activity are the diagnosis and treatment of epilepsy in children and adults. Narrow specialization - surgical treatment of epilepsy, genetics of epilepsy. Neurogenetics.

Scientific publications

Sharkov A., Sharkova I., Golovteev A., Ugarov I. "Optimization of differential diagnostics and interpretation of results of genetic testing by XGenCloud expert system in some forms of epilepsy". Medical Genetics, No. 4, 2015, p. 41.
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Sharkov A.A., Vorobyov A.N., Troitsky A.A., Savkina I.S., Dorofeeva M.Yu., Melikyan A.G., Golovteev A.L. "Surgery for epilepsy in multifocal brain lesions in children with tuberous sclerosis." Abstracts of the XIV Russian Congress "INNOVATIVE TECHNOLOGIES IN PEDIATRICS AND PEDIATRIC SURGERY". Russian Bulletin of Perinatology and Pediatrics, 4, 2015. - p.226-227.
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Dadali E.L., Belousova E.D., Sharkov A.A. "Molecular genetic approaches to the diagnosis of monogenic idiopathic and symptomatic epilepsy". Abstract of the XIV Russian Congress "INNOVATIVE TECHNOLOGIES IN PEDIATRICS AND PEDIATRIC SURGERY". Russian Bulletin of Perinatology and Pediatrics, 4, 2015. - p.221.
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Sharkov A.A., Dadali E.L., Sharkova I.V. "A rare variant of type 2 early epileptic encephalopathy caused by mutations in the CDKL5 gene in a male patient." Conference "Epileptology in the system of neurosciences". Collection of conference materials: / Edited by: prof. Neznanova N.G., prof. Mikhailova V.A. St. Petersburg: 2015. - p. 210-212.
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Dadali E.L., Sharkov A.A., Kanivets I.V., Gundorova P., Fominykh V.V., Sharkova I.V. Troitsky A.A., Golovteev A.L., Polyakov A.V. A new allelic variant of type 3 myoclonus epilepsy caused by mutations in the KCTD7 gene // Medical genetics.-2015.- v.14.-№9.- p.44-47
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Dadali E.L., Sharkova I.V., Sharkov A.A., Akimova I.A. "Clinical and genetic features and modern methods of diagnosing hereditary epilepsy". Collection of materials "Molecular biological technologies in medical practice" / Ed. corresponding member RANEN A.B. Maslennikova.- Issue. 24.- Novosibirsk: Academizdat, 2016.- 262: p. 52-63
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Belousova E.D., Dorofeeva M.Yu., Sharkov A.A. Epilepsy in tuberous sclerosis. In "Brain Diseases, Medical and Social Aspects" edited by Gusev E.I., Gekht A.B., Moscow; 2016; pp.391-399
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Dadali E.L., Sharkov A.A., Sharkova I.V., Kanivets I.V., Konovalov F.A., Akimova I.A. Hereditary diseases and syndromes accompanied by febrile convulsions: clinical and genetic characteristics and diagnostic methods. //Russian Journal of Children's Neurology.- T. 11.- No. 2, p. 33-41. doi: 10.17650/ 2073-8803-2016-11-2-33-41
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Sharkov A.A., Konovalov F.A., Sharkova I.V., Belousova E.D., Dadali E.L. Molecular genetic approaches to the diagnosis of epileptic encephalopathies. Collection of abstracts "VI BALTIC CONGRESS ON CHILDREN'S NEUROLOGY" / Edited by Professor Guzeva V.I. St. Petersburg, 2016, p. 391
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Hemispherotomy in drug-resistant epilepsy in children with bilateral brain damage Zubkova N.S., Altunina G.E., Zemlyansky M.Yu., Troitsky A.A., Sharkov A.A., Golovteev A.L. Collection of abstracts "VI BALTIC CONGRESS ON CHILDREN'S NEUROLOGY" / Edited by Professor Guzeva V.I. St. Petersburg, 2016, p. 157.
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Article: Genetics and differentiated treatment of early epileptic encephalopathies. A.A. Sharkov*, I.V. Sharkova, E.D. Belousova, E.L. Dadali. Journal of Neurology and Psychiatry, 9, 2016; Issue. 2doi:10.17116/jnevro20161169267-73
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Golovteev A.L., Sharkov A.A., Troitsky A.A., Altunina G.E., Zemlyansky M.Yu., Kopachev D.N., Dorofeeva M.Yu. "Surgical treatment of epilepsy in tuberous sclerosis" edited by Dorofeeva M.Yu., Moscow; 2017; p.274
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New international classifications of epilepsy and epileptic seizures of the International League against epilepsy. Journal of Neurology and Psychiatry. C.C. Korsakov. 2017. V. 117. No. 7. S. 99-106

Head of
"Prenatal Diagnosis"

Kyiv
Yulia Kirillovna

In 2011 she graduated from the Moscow State Medical and Dental University. A.I. Evdokimova with a degree in General Medicine Studied in residency at the Department of Medical Genetics of the same university with a degree in Genetics

In 2015, she completed an internship in Obstetrics and Gynecology at the Medical Institute for Postgraduate Medical Education of the Federal State Budgetary Educational Institution of Higher Professional Education "MGUPP"

Since 2013, he has been conducting a consultative appointment at the Center for Family Planning and Reproduction, DZM

Since 2017, he has been the head of the Prenatal Diagnostics department of the Genomed laboratory

Regularly makes presentations at conferences and seminars. Reads lectures for doctors of various specialties in the field of reproduction and prenatal diagnostics

Conducts medical genetic counseling for pregnant women on prenatal diagnostics in order to prevent the birth of children with congenital malformations, as well as families with presumably hereditary or congenital pathologies. Conducts interpretation of the obtained results of DNA diagnostics.

SPECIALISTS

Latypov
Artur Shamilevich

Latypov Artur Shamilevich – doctor geneticist of the highest qualification category.

After graduating from the medical faculty of the Kazan State Medical Institute in 1976, for many years he worked first as a doctor in the office of medical genetics, then as head of the medical genetic center of the Republican Hospital of Tatarstan, chief specialist of the Ministry of Health of the Republic of Tatarstan, teacher at the departments of Kazan Medical University.

Author of more than 20 scientific papers on the problems of reproductive and biochemical genetics, participant in many domestic and international congresses and conferences on the problems of medical genetics. He introduced methods of mass screening of pregnant women and newborns for hereditary diseases into the practical work of the center, performed thousands of invasive procedures for suspected hereditary diseases of the fetus at different stages of pregnancy.

Since 2012, she has been working at the Department of Medical Genetics with a course in prenatal diagnostics at the Russian Academy of Postgraduate Education.

Research interests – metabolic diseases in children, prenatal diagnostics.

Doctors are admitted by appointment.

Geneticist

Gabelko
Denis Igorevich

In 2009 he graduated from the medical faculty of KSMU named after. S. V. Kurashova (specialty "Medicine").

Internship at the St. Petersburg Medical Academy of Postgraduate Education of the Federal Agency for Health and Social Development (specialty "Genetics").

Internship in Therapy. Primary retraining in the specialty "Ultrasound diagnostics". Since 2016, he has been an employee of the Department of the Department of Fundamental Foundations of Clinical Medicine of the Institute of Fundamental Medicine and Biology.

Area of ​​professional interests: prenatal diagnosis, the use of modern screening and diagnostic methods to identify the genetic pathology of the fetus. Determining the risk of recurrence of hereditary diseases in the family.

Participant of scientific and practical conferences on genetics and obstetrics and gynecology.

Work experience 5 years.

Doctors are admitted by appointment.

Geneticist

Grishina
Christina Alexandrovna

In 2015 she graduated from the Moscow State Medical and Dental University with a degree in General Medicine. In the same year, she entered residency in the specialty 30.08.30 "Genetics" at the Federal State Budgetary Scientific Institution "Medical Genetic Research Center".
She was hired in the Laboratory of Molecular Genetics of Complexly Inherited Diseases (Head - Doctor of Biological Sciences Karpukhin A.V.) in March 2015 as a research laboratory assistant. Since September 2015, she has been transferred to the position of a researcher. He is the author and co-author of more than 10 articles and abstracts on clinical genetics, oncogenetics and molecular oncology in Russian and foreign journals. Regular participant of conferences on medical genetics.

Area of ​​scientific and practical interests: medical genetic counseling of patients with hereditary syndromic and multifactorial pathology.

Consultation with a geneticist allows you to answer the following questions:

Are the child's symptoms signs of a hereditary disease? what research is needed to identify the cause determining an accurate forecast recommendations for conducting and evaluating the results of prenatal diagnosis everything you need to know about family planning IVF planning consultation field and online consultations

took part in the scientific-practical school "Innovative genetic technologies for doctors: application in clinical practice", the conference of the European Society of Human Genetics (ESHG) and other conferences dedicated to human genetics.

Conducts medical genetic counseling for families with presumably hereditary or congenital pathologies, including monogenic diseases and chromosomal abnormalities, determines indications for laboratory genetic studies, interprets the results of DNA diagnostics. Advises pregnant women on prenatal diagnostics in order to prevent the birth of children with congenital malformations.

Geneticist, obstetrician-gynecologist, candidate of medical sciences

Kudryavtseva
Elena Vladimirovna

Geneticist, obstetrician-gynecologist, candidate of medical sciences.

Specialist in the field of reproductive counseling and hereditary pathology.

Graduated from the Ural State Medical Academy in 2005.

Residency in Obstetrics and Gynecology

Internship in the specialty "Genetics"

Professional retraining in the specialty "Ultrasound diagnostics"

Activities:

• Infertility and miscarriage
Vasilisa Yurievna



She is a graduate of the Nizhny Novgorod State Medical Academy, Faculty of Medicine (specialty "Medicine"). She graduated from the clinical internship of the FBGNU "MGNTS" with a degree in "Genetics". In 2014, she completed an internship at the clinic of motherhood and childhood (IRCCS materno infantile Burlo Garofolo, Trieste, Italy).

Since 2016, she has been working as a consultant doctor at Genomed LLC.

Regularly participates in scientific and practical conferences on genetics.

Main activities: Consulting on clinical and laboratory diagnostics of genetic diseases and interpretation of results. Management of patients and their families with suspected hereditary pathology. Consulting when planning a pregnancy, as well as during pregnancy on prenatal diagnostics in order to prevent the birth of children with congenital pathology.

Breast cancer (BC) is a common type of oncology and, unfortunately, no method of therapy has yet been developed that gives a full guarantee of cure. Therefore, the best way out for the patient is prevention and timely diagnosis of breast cancer. Fish - analysis for breast cancer is the most modern research method that allows you to direct the treatment of the patient along the most correct path.

Despite the vast experience gained in the study and treatment of this disease, medicine is still not able to indicate the external factors that cause a malignant tumor of the breast. None of the known carcinogens can be reliably associated with the occurrence of this disease. Modern diagnostic methods generally give good results and allow you to accurately determine the presence or absence of the disease and the stage of development. However, not all of them provide comprehensive information that allows you to accurately prescribe treatment.

1. Complete blood count - checks the level of leukocytes, erythrocyte sedimentation rate and hemoglobin. The first two indicators in oncology increase, the last, on the contrary, decreases. However, this analysis allows us to judge only the presence of certain problems in the body. It is impossible to make an accurate diagnosis of "breast cancer" with its help, especially at an early stage of tumor development.
2. Biochemistry - determines the level of enzymes and electrolytes, which makes it possible to judge the presence of metastases. However, these data are not always objective. This study also shows the presence in the blood of some oncomarkers that help track the presence of a cancerous tumor and its location.
3. Spectral analysis allows you to determine the presence of cancer with a probability of more than 90%, including at an early stage. The method is based on the study of blood under infrared radiation, which allows you to determine its molecular composition.
4. Biopsy - is performed by taking a tissue sample from the breast and further cytological analysis, which determines the presence of cancer cells and their number, which depends on the degree of development of the disease.
5. Genetic analysis determines the patient's predisposition to the formation of breast cancer. It is carried out by detecting certain genes in the blood that are responsible for the transmission of cancer from generation to generation.

However, the latest and most effective research method today is the so-called FISH (fish) test. The abbreviation in translation from English sounds like “intracellular fluorescent hybridization”.

The fish testing method is relatively new - it has been used since 1980. However, despite the complexity and high price, he managed to earn positive reviews from both doctors and patients who, thanks to him, successfully got rid of cancer.

A gene called HER2 is responsible for the growth of breast cells in the human body. The name translated from English means Human Estrogen Receptor - 2. Normally, the receptors of this gene produce HER2, a protein that regulates the division of gland cells. A cancerous tumor (usually a carcinoma) at its inception "cheats" this gene, forcing it to grow additional tissue that will be used by the tumor for its development. This anomaly appears in about 30% of cases and is characterized by the term "amplification".

Thus, the patient's body itself helps to develop oncology. If this process is not stopped, then even the most modern and powerful methods of treatment may not help the patient.

The study of amplification of the HER2 gene is usually carried out in two stages:

• IHC (immunohistochemical test);
• directly FISH - analysis (fluorescent hybridization).

Under local anesthesia, the patient undergoes a biopsy - taking tissue samples that are sent to a specialized laboratory.

First, immunohistochemistry is usually performed - a microscopic analysis of a tissue sample of a cancerous tumor. It determines the fundamental presence of the HER2 gene in the tumor tissue. This study is much cheaper than the fish test, and is also easier and faster to perform. However, it does not provide such accurate information. The result is determined in numbers from zero to three points. If the result is less than or equal to one, then the HER2 gene is absent in the tumor and there is no need for further research. From two to three points - a borderline condition, more than three - a malignant formation is in the process of growth and it is necessary to proceed to the second stage of diagnosis.

A fish study for breast cancer is performed as follows: elements of DNA (deoxyribonucleic acid) molecules labeled with a special dye are introduced into the blood. These markers are inserted into the patient's DNA molecules and determine whether and how much HER2 amplification is taking place. The analysis is carried out in real time, the doctor compares the rate of division of the gene at the site of the alleged tumor with the rate of division of the usual area of ​​the breast.

In breast cancer, a FISH study can provide the following results:

• the reaction is positive - the rate of division of the HER2 gene in the tumor tissue exceeds the normal two times or more, in which case additional therapy is required;
• the reaction is negative - HER2 is not involved in the process of cancer cell division and, if a tumor is still present, this gene will not catalyze its development.

Thus, the analysis makes it possible to determine the incorrect behavior of the HER2 gene and correct the treatment by applying in parallel therapy aimed at suppressing this gene. Currently, the drug Herceptin is used for this.

If the fish test is not done in a timely manner or if the results are not paid attention to, the doctor will not have data on the behavior of HER2. In this case, the treatment will be prescribed without taking into account the possible aggressive activity of this gene. Most likely, such therapy will not bring results - the tumor will continue to aggressively develop.

In addition to the above, tracking the behavior of the HER2 gene gives oncologists an understanding of the degree of tumor aggressiveness and the ability to predict the rate of its growth and spread. This plays a very important role in the design of the patient's treatment. It is determined whether there is a need for the appointment of severe treatment (for example, radiation or chemotherapy), or hormone therapy will be enough, whether surgery makes sense or is not necessary.

Pros and Cons of Fish Analysis

Like any other diagnostic method, FISH research has its pros and cons.

1. The study is carried out quickly - the result is ready in a few days, while other diagnostic methods take up to several weeks. This moment is extremely important in the fight against oncology.
2. In addition to the study of breast cancer, the analysis allows you to find out the predisposition of a patient to oncology of any abdominal organ. The patient is provided with a detailed report, guided by which he can undergo further examinations to prevent the possible development of cancer.
3. Due to the specifics of fish analysis, it can detect the most insignificant genetic anomalies that cannot be diagnosed by other methods.
4. Unlike some other types of research, the fish test is safe for the patient. In addition to a biopsy, it does not require any additional traumatic effects.

Some oncologists consider the effectiveness of the fish test controversial. They are based on studies that have not shown a significant advantage of this method over the cheaper IHC study.

• high cost of research;
• due to the fact that the markers introduced into DNA are somewhat specific, they cannot be used on some parts of the chromosomes;
• the analysis does not reveal all genetic damage, which can lead to diagnostic errors.

In general, despite criticism, fish analysis is the fastest and most accurate of the methods for diagnosing breast carcinoma. It is also important that it allows predicting the development of some other types of oncology.

Any cancer is easiest to treat in the early stages of development. Unfortunately, ironically, most of the known types of malignant tumors are extremely difficult to diagnose in the early stages. In addition, many of the diagnostic methods used are time consuming and do not provide a completely objective picture. Fish analysis not only provides the most accurate picture of the state of the tumor, but also allows you to save the patient from destructive forms of treatment for the body (for example, chemotherapy), since the degree of tumor aggressiveness and, accordingly, the likelihood of metastases is determined.

This method is currently used to diagnose certain types of cancerous tumors, since the malignant transformation of a cell is due to changes in its genome. Accordingly, having found characteristic disorders in the genes, this cell can be classified with high certainty as cancerous. In addition, the FISH test is also used to confirm an already established diagnosis, as well as to obtain additional data on the possibility of using specific chemotherapy drugs for the purpose of chemotherapy for breast cancer and to clarify the prognosis of the disease.

A good example of the use of a FISH test is in patients with breast cancer. With this technique, biopsy tissue is examined for copies of a gene called HER-2. If this gene is present, it means that a large number of HER2 receptors are located on the cell surface. They are sensitive to signals that stimulate the development and reproduction of tumor elements. In this case, an opportunity opens up for the effective use of trastuzumab - this drug blocks the activity of HER2 receptors, which means it inhibits tumor growth.

How is the FISH test performed?

These deviations in the structure of chromosomes are of several types:
translocation - the movement of a piece of chromosomal material to a new position within the same or another chromosome;
inversion - rotation of a part of the chromosome by 1800 without separation from its main body;
deletion - loss of any chromosomal region;
duplication - copying part of the chromosome, which leads to an increase in the number of copies of the same gene contained in the cell.

Each of these disorders carries certain diagnostic signs and information. For example, translocations may indicate the presence of leukemias, lymphomas or sarcomas, and the presence of gene duplications helps to prescribe the most effective therapy.

What is the advantage of the FISH test?

Another advantage of the FISH test is that it can be used on material recently obtained from a patient. For standard cytogenetic analysis, it is necessary to first grow a cell culture, that is, allow the patient's cells to multiply in the laboratory. This process takes about 2 weeks, and it takes another week to conduct a routine study, while the result of the FISH test will be received in just a few days.

The steady development of medical science is gradually leading to a reduction in the cost of the FISH test and its ever wider entry into the daily practice of oncologists.

In all cases, without exception, the formation and growth is associated with the activity of the HER2 type gene. It is he who is responsible for how much protein will be allocated to the female body for the development of breast tissue. When the first healthy cells are transformed into malignant ones, the gene receptors receive information that additional division of cellular material is required.

The gene starts a program to build additional tissue inside the breast, although in reality this cellular material will be used by the tumor for its growth and development. So, carcinoma, in fact, deceives the body, and forces it to feed the cancer at the expense of its own resources.

The task of fish analysis in breast cancer is precisely to identify the malfunctioning of the HER2 gene, and take appropriate response measures in terms of prescribing adequate medical treatment.

If a fish test is not carried out in a timely manner for breast cancer, then even if certain drugs are used in the treatment process, this can lead to the fact that the tumor will continue to aggressively develop, covering all new breast tissues. These are the so-called consequences of incorrectly prescribed therapy due to the lack of objective data on the functioning of the HER2 gene.

In the process of passing the fish analysis, the doctor introduces into the patient's blood special substances containing coloring elements that can visualize the picture of chromosomal disorders. Thus, the doctor is able to visually see and further study the genetic abnormalities in the woman's genome that led to the development of breast cancer.

If abnormalities in the work of the HER2 gene are confirmed, then appropriate treatment is prescribed. If not, then the doctor, using other tests, establishes a different reason for the development of breast cancer.

Another important advantage of fish analysis is that in a couple of days the patient receives a comprehensive report on the genetic predisposition to the development of a particular cancer. With the help of this medical testing, it is possible to simultaneously diagnose the pathology of not only the mammary gland, but also all abdominal organs.

Informative video

Because the FISH test can detect cancer-causing genetic abnormalities, it is an effective method for diagnosing certain types of cancer. The test is also used to confirm the diagnosis and provides additional information about the possible outcome of the disease and the advisability of chemotherapy.

For example, in patients with breast cancer, a FISH test of tissue taken during a biopsy helps determine the presence of copies of the HER2 gene in the cells.

Cells with copies of the HER2 gene have more HER2 receptors, which receive signals that stimulate the growth of cancer cells in the breast. Therefore, for patients with copies of the HER2 gene, it is advisable to use Herceptin (trastuzumab), a drug that inhibits the ability of HER2 receptors to receive signals.

Due to the high cost and relative inaccessibility of the FISH test, another test for detecting breast cancer, immunohistochemistry (IHC), is more commonly used.

There is controversy in medical circles regarding the high performance of the FISH test compared to standard tests. However, due to technological advances, the FISH test is becoming cheaper and more accessible in a variety of clinical settings.

How the FISH test works

When conducting a FISH test on a patient tissue sample, fluorescent labels are used that bind only to certain regions of the chromosomes. Then, with the help of a fluorescent microscope, the regions of the chromosomes to which the fluorescent probes have contacted are determined, and the presence of possible abnormalities that provoke the development of cancer.

Cancer cells may show the following abnormalities:

• translocation - the transfer of a section of a chromosome to a new position on the same or another chromosome;
• inversion - a turn of a section of a chromosome by 180 degrees while maintaining a connection with the chromosome itself;
• deletion - loss of part of a chromosome;
• duplication - doubling of a section of a chromosome, leading to an excess content of copies of a gene in a cell.

Translocations help diagnose some types of leukemia, lymphoma, and sarcoma. The presence of a duplication in breast cancer cells helps the doctor choose the best treatment.

The advantage of the FISH test over standard cytogenetic tests (which examine the genetic composition of cells) is that it can detect even the smallest genetic changes that cannot be seen with a conventional microscope.

Another important feature of the FISH test is that it can be performed on cells that have not yet begun to actively develop. Other tests are only performed on cells after they have been grown in the lab for two weeks, so the entire process can take up to three weeks, with FISH test results available within a few days.

Examples of a FISH test for cancer diagnosis

Although the FISH test is most commonly used to analyze genetic abnormalities in breast cancer, it also provides important information about other types of cancer.

For example, when diagnosing bladder cancer, a FISH test for urine cells is more accurate than tests for atypical cells. In addition, it allows you to determine the recurrence of bladder cancer 3-6 months earlier.

The FISH test also helps detect chromosomal abnormalities in leukemia, including cells that are indicative of an aggressive form of chronic lymphocytic leukemia (CLL). Patients with an aggressive form of CLL may require urgent treatment, while for less aggressive forms, observation may be sufficient.

FISH test controversy

Not all experts agree that the FISH test is the most accurate test for diagnosing Herceptin-susceptible cancers.

In 2010, scientists from the Mayo Institute (Ireland) stated that the less expensive IHC test is almost as effective in determining susceptibility to Herceptin as the FISH test.

Other experts have criticized the FISH test for failing to detect small mutations such as small deletions, insertions, and point mutations, and for ignoring some inversions.

Improvement of the FISH test

Despite the fact that the FISH test technology does not yet allow analyzing all parts of the chromosomes, it is constantly developing in this direction.

For example, in 2007, Canadian scientists announced the development of a microscope slide-sized chip that would allow a FISH test to be performed using a device that fits in the palm of your hand.

Called the FISH Test on a Chip, this improved test will deliver results in one day and cost less than other tests.