Cancer screening

Cancer examination begins with collecting complaints and anamnesis. A thorough collection of complaints and anamnesis during an individual interview depends on the doctor's preparation and his ability to communicate with the patient.

The patient is questioned according to a specific scheme. Changes in the patient's general condition (weight loss, fever, weakness, swelling, headache, etc.), the state of the respiratory, cardiovascular, nervous systems, and the gastrointestinal tract are determined. Particular attention is paid to "alarm signals", which include hemoptysis, jaundice, enlarged lymph nodes, micro- and macrohematuria, blood in the stool, etc. If "alarm signals" appear, an in-depth examination should be conducted to exclude a diagnosis of oncological disease.

It is important to remember that in the early stages of malignant tumor development, the patient may not present any specific complaints, with the exception of individuals with precancerous diseases. In such cases, suspicion of malignancy should arise when the nature of sensations that the patient has noted before, possibly for several years, changes.

It is important when collecting anamnesis not to limit yourself to identifying the symptoms of a disease of one organ. It is necessary to focus on previous medical and surgical interventions, which can help in diagnosing the current disease as a relapse or metastasis of a removed tumor.

Such examination for cancer as inspection and palpation of the patient along with collecting anamnesis are an important component of diagnosing a malignant tumor. The main rule for doctors should be a complete external oncological examination of the patient, which includes inspection and palpation of the skin, visible mucous membranes, all peripheral lymph nodes (occipital, cervical, submandibular, supra- and subclavian, axillary, cubital, inguinal and popliteal), thyroid, mammary glands, as well as the cervix, in men - testicles, rectum. Such tactics are explained by the following points. Firstly, local damage may be secondary signs (distant metastases) of a tumor localized in a completely different place. For example, the supraclavicular lymph nodes on the left can be affected by cancer of the gastrointestinal tract, cancer of the left lung, lymphogranulomatosis, lymphomas, etc. Secondly, the synchronous occurrence of multiple tumors of the same (basalioma, skin melanoma) or different localizations is possible. Thirdly, during a full examination of the patient, it is necessary to identify significant concomitant pathology, which may affect the scope of additional examination and the nature of treatment. After completing the physical examination, the doctor must decide which additional diagnostic methods are indicated in this case.

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Instrumental examination for cancer

Instrumental examination for cancer is determined by the characteristics of the spread of the tumor process in the body:

• determination of the spread of the tumor process within the affected organ: the size of the tumor, its location relative to the anatomical structures of the organ, the anatomical form of growth, the degree of invasion into the wall of the hollow organ, and the growth of adjacent organs and tissues are specified;
• examination of regional lymph drainage zones to detect possible metastatic lesions of the lymph nodes;
• identification of probable distant organ metastases taking into account the priority of their occurrence in tumors of various localizations.

For these purposes, modern methods of visualization of internal organs from the arsenal of radiation and endoscopic diagnostics are used.

Radiological diagnostics - this examination for cancer includes several main types.

1. X-ray diagnostics:
   • basic radiodiagnostics;
   • computed tomography (CT);
   • magnetic resonance imaging (MRI).
2. Radionuclide diagnostics.
3. Ultrasound diagnostics.

Basic X-ray diagnostics

Cancer screening includes fluoroscopy (X-ray television scanning on devices equipped with X-ray image intensifiers - URI), fluorography, radiography and linear tomography, etc.

X-ray television scanning is mainly used for contrast studies of the gastrointestinal tract and respiratory system. In addition to visual data, the radiologist can obtain X-ray images called target or overview depending on the breadth of coverage of the object being studied. Puncture biopsy and X-ray endoscopic procedures can also be performed under X-ray television control.

X-ray examination for cancer of the upper gastrointestinal tract is the main method for diagnosing tumors of the pharynx, esophagus, stomach and duodenum, which are examined simultaneously. First, the first portion of the barium mixture taken by the patient provides a tight filling of the esophagus and an image of the internal relief of the stomach. Then, after taking up to two glasses of barium suspension, a tight filling of the stomach is achieved. When using a gas-forming mixture or physiological swallowing of air, double contrast is obtained, allowing the relief of the gastric mucosa to be examined. The relief of the mucosa of the outlet of the stomach and duodenum is examined by metered compression with a special device (tube) on an X-ray machine.

Irrigoscopy - retrograde contrast enema - this cancer examination is used to examine the rectum and colon. Under fluoroscopy control using the Bobrov apparatus, up to 4.5 liters of contrast mass are introduced into the lumen of the rectum to obtain a tight filling of the colon. After emptying the intestines, the relief of the mucous membrane is visible on the radiographs. For double contrast, the colon is filled with air, which produces a picture of the internal relief and all anatomical features.

Irrigoscopy is performed after a digital rectal examination and rectoscopy, previously performed by a proctologist, since these parts of the colon are poorly visible during irrigoscopy. Contrast fluoroscopy of the hollow organs of the gastrointestinal tract reveals the following symptoms of tumor damage:

• filling defect, characteristic of tumors that grow exophytically into the lumen of the organ;
• persistent (organic) narrowing of the lumen of a hollow organ with its deformation, which is typical for the infiltrative form of cancer with circular lesions;
• rigidity of the wall in a limited area (determined by tight filling and double contrasting), characteristic of infiltrative cancer growing in the wall of the organ and outside of it.

Based on indirect radiological signs, when external compression is detected, it is possible to assume the presence of a tumor in adjacent organs.

X-ray examination for cancer (along with diagnostic fluorography) is widely used in the diagnosis of pulmonary pathology and the musculoskeletal system.

When studying pulmonary pathology, such changes as single or multiple lesions and foci, ventilation disorders (hypoventilation, valvular emphysema, atelectasis), pathological changes in the root of the lung (its expansion with loss of structure), expansion of the mediastinal shadow (with damage to the mediastinal lymph nodes or with mediastinal tumors), the presence of fluid in the pleural cavity or compaction on the paracostal or interlobar pleura (with specific metastatic pleurisy or pleural mesothelioma) are monitored.

When studying bone and joint pathology, it is possible to detect such signs of malignant damage as thickening of the bone with its deformation, destruction of spongy or compact substance, osteoplastic foci.

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Computer tomography

In the future, linear or computed tomography is required to clarify the diagnosis.

Linear tomography (LT) is a method for studying sections of internal organs when examining the lungs, mediastinum and musculoskeletal system.

This cancer examination allows for peripheral lung cancer or pleural tumors to obtain a clear image of the pathological focus, assess its contours, structure and relationship to surrounding tissues.

In central lung cancer, RT allows obtaining an image of the tumor in the root of the lung, lobar or segmental bronchus with an assessment of the degree of its patency.

When diagnosing hilar or mediastinal lymphadenopathy, it is possible to detect affected lymph nodes, since with RT, unlike with computed tomography, normal lymph nodes are not visible.

And finally, in the diagnosis of laryngeal tumors, RT allows the detection of additional tissues and deformation of the lumen of the organ.

Special types of radiography, such as cholecystography, mammography and its varieties (cystography and ductography), radiography under conditions of artificial pneumothorax, pneumoperitoneum, parietography, fistulography, endoscopic retrograde cholangiopancreatography, as well as angiography, lymphography, excretory urography and other types of research, are carried out exclusively in specialized institutions.

Computer tomography (CT), or X-ray computed tomography (X-ray computed tomography) is an X-ray examination for cancer based on computer processing of data on the degree of absorption of X-ray radiation at different points of the object being studied. The main purpose of CT is to diagnose oncological diseases accompanied by volumetric formations.

The resulting images are, in their anatomical essence, practically analogous to Pirogov's anatomical sections of the human body.

In CT of the brain, orbit, base and cranial vault bones, primary and metastatic tumors are detected starting from 7-8 mm. However, only the destruction of the orbital bone walls and tumor spread to surrounding anatomical structures are reliable signs of malignancy; in the absence of these signs, it is not possible to determine the degree of malignancy.

With CT scanning of the facial skull, paranasal sinuses, nasal cavity, and nasopharynx, additional neoplasms in the soft tissues of the face and paranasal sinuses are easily visualized.

Computer tomography of the neck allows for good diagnostics of tumors and cysts of the neck, damage to the lymph nodes. When examining the thyroid gland, difficulties arise due to the layering of the bones of the upper shoulder girdle. However, large tumor nodes are visible without distortion, while the relationship of the tumor with the surrounding tissues and anatomical zones, including the upper mediastinum, is clearly traced.

In case of tumors of the laryngopharynx and larynx, CT is used mainly to determine the extra-organ spread of the tumor.

CT data of the chest organs (mediastinum, lungs, pleura) are almost identical to those obtained with basic X-ray diagnostics. However, CT can provide more accurate information about tumor growth into surrounding structures.

Computed tomography of the abdominal organs and retroperitoneal space does not have significant advantages over basic X-ray diagnostic methods.

In the study of the musculoskeletal system, the efficiency of CT exceeds that of basic X-ray diagnostics and is an effective method for assessing the condition of large flat and long tubular bones. In the diagnosis of primary bone tumors, CT makes it possible to obtain an image of the intraosseous and extraosseous soft tissue component of the tumor. In soft tissue tumors, the main advantage of CT is the ability to determine their relationships with bones, joints and other anatomical structures.

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MRI

Magnetic resonance imaging (MRI) is based on recording radio waves emitted by magnetized hydrogen atoms after exposure to an external radio wave signal, and computer processing of the data. MRI can be used to obtain images of organs and tissues containing any amount of water (excitation of hydrogen atoms). Formations that do not contain water or carbon are not displayed on MRI. The accuracy and sensitivity of MRI exceed similar indicators of CT in different areas by 2-40%. CT and MRI have almost equal capabilities in diagnosing pathologies of the brain tissue, tracheobronchial tree and lung parenchyma, parenchymatous organs of the abdominal cavity and retroperitoneal space, large flat bones, lymph nodes of any groups. However, when studying the brain stem and the entire spinal cord, heart and vascular structures, limbs (especially joints), and pelvic organs, MRI has the advantage. In oncological practice, MRI is necessary for differential diagnosis of primary and secondary tumors of the central nervous system (trunk, spinal cord), heart and pericardium, and spine.

Radionuclide diagnostics (RND)

This is a cancer examination based on the registration of images from objects emitting gamma rays. For this purpose, radiopharmaceuticals (RP) containing radionuclides are introduced into the human body. The spatial distribution of RPP in the internal organs is determined using scanning devices and scintillation gamma cameras. Isotope methods can be used to obtain an anatomical and topographic image of organs, evaluate data on their position and size, as well as the nature of the distribution of radioactive pharmacological drugs in them. Positive scintigraphy is based on the intensive absorption of the drug by tumor tissue. The presence of increased accumulation of RND in any area of the organ being examined indicates the presence of a pathological focus. This method is used to detect primary and metastatic tumors of the lungs, brain, bones and some other organs. With negative scintigraphy, defects in isotope absorption are detected, which also indicates a volumetric pathological process in the organ. This principle is the basis for the diagnosis of primary and metastatic tumors of parenchymal organs: liver, kidneys, thyroid and pancreas.

Emission computed tomographs are equipped with a rotation system of the built-in gamma camera, which allows for the reconstruction of a sectional image (single-photon emission computed tomography - SPECT). In addition to functional studies of various organs, it is possible to obtain information on structural disorders. Thus, skeletal scintigraphy is widely used, allowing for the detection of clinically hidden metastases in the bone and joint system.

Positron emission tomography (PET) is based on the use of positrons emitted by radionuclides. Cyclotrons are used to produce radionuclides in PET. This type of tomography allows the study of hidden metabolic processes.

Ultrasound diagnostics (ultrasound, sonotomography)

This cancer examination occupies a significant place in radiation diagnostics. The physical basis of this method is obtaining a computer picture from the ultrasound signal reflected by organs and tissues. The ultrasound methods used are divided into screening, basic and specialized. Screening procedures highlight pathological areas against the background of a normal picture (recognition of "friend or foe"). Basic studies are limited to studying the abdominal organs, retroperitoneal space, small pelvis, thyroid and mammary glands, superficial lymph nodes.

Specialized cancer examination is performed using intracavitary sensors (rectal, vaginal, esophageal), cardiovascular sensors, with puncture biopsy. Modern devices equipped with the sono-CT function are capable of constructing a cross-section with a picture similar to a computer tomogram. Ultrasound is successfully used for primary and secondary tumors and concomitant pathology of the liver, pancreas, spleen, kidneys, prostate, uterus, extraorgan tumors of the abdominal cavity, retroperitoneal space and small pelvis.

Endoscopic examination for cancer

In modern oncology, endoscopic research methods occupy one of the leading places in the diagnosis of malignant tumors.

Endoscopy is a visual examination of hollow organs and body cavities for cancer using special optical-mechanical devices - endoscopes. The latter can be rigid or flexible. The design of endoscopes is based on the use of fiber optics, they are less traumatic and more suitable for instrumental palpation and biopsy. Rigid endoscopes are used in proctology (rectoscopy), anesthesiology (laryngoscopy).

Endoscopic diagnostic methods allow us to solve the following problems in oncology:

• primary diagnosis of malignant tumors of a number of organs of the chest and abdominal cavities;
• differential diagnostics of pathological processes in individual organs and cavities of the body in cases where a preliminary examination does not allow us to exclude the presence of a malignant disease in the patient;
• clarifying diagnostics, allowing for a more accurate determination of the location, size, anatomical shape, intra-organ and extra-organ boundaries of the identified tumor;
• morphological diagnostics using targeted biopsy;
• early diagnosis of malignant tumors and detection of precancerous diseases during preventive examinations of the population using endoscopic research methods;
• dispensary observation of patients with benign tumors and chronic diseases that may serve as a basis for the development of cancer;
• monitoring the effectiveness of treatment of patients with malignant tumors for timely diagnosis of relapses and metastases;
• Electrosurgical excision of polyps with clarification of their histological structure.

Currently, targeted biopsy and cytological examination are an essential component of a comprehensive endoscopic examination. The main types of endoscopic biopsy are forceps, brush (brush biopsy) and loop. In forceps and loop biopsy, smears-imprints (for cytology) and directly tissue pieces (for histology) are sent for morphological examination, in brush biopsy, the obtained structureless material is examined only cytologically. In bronchoscopy, bronchial lavage waters can be used for cytological examination.

The most widely used endoscopic methods are fibrogastroduodenoscopy, including fibroesophagoscopy and fibrogastroscopy in the form of variants. Endoscopic examination for esophageal cancer allows diagnosing most tumors of this organ, obtaining indirect signs of mediastinal neoplasms and lymph node lesions.

In diagnostics of stomach tumors, the method is effective in recognizing exophytic tumors. Fibroidoduodenoscopy allows obtaining indirect signs of pancreatic head cancer or obvious signs of its growth into the duodenum.

Fibrocolonoscopy is an examination for colon cancer. The study allows to detect organic stenosis caused by endophytic cancer, exophytic tumors, and to perform their biopsy. For therapeutic purposes, it is used for polypectomy.

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Videoendoscopy

Currently, video endofibroscopes are being introduced into endoscopic diagnostics, designed to conduct studies of the mucous membrane of the esophagus, stomach, duodenum and colon for diagnostic and therapeutic purposes. The entire process of endoscopic examination (i.e. the image of the cavity and walls of the organ) is displayed on the monitor screen in color, with the possibility of simultaneous recording on videotape for subsequent repeated viewing.

Retrograde cholangiopancreatoscopy allows for preoperative visual examination of the pancreatic ducts and biliary system.

Colposcopy (examination of the cervix) and hysteroscopy (endoscopy of the uterine cavity) are the leading examinations for cancer in gynecological oncology.

Urethroscopic examination and cystoscopy are used both for primary diagnostics of urinary tract neoplasms and for timely recognition of tumor relapses during follow-up observation of patients after radical treatment. Repeated endoscopic examinations during chemotherapy and radiation therapy allow us to track the reaction of the tumor and normal tissues of the organ to the effects of treatment factors.

Laparoscopy - examination of the abdominal cavity and pelvic organs in the following volume: the lower surface of the liver, parietal and visceral peritoneum, part of the intestine, part of the female genital area. This cancer examination is used to search for distant metastases, peritoneal or other extra-organ tumors with subsequent biopsy.

Fibroepipharingoscopy is an endoscopic examination for cancer of the upper respiratory tract. This method allows visualizing the primary tumor, assessing its spread along the walls of the pharynx, determining the growth form, and, based on endoscopic semiotics and the biopsy result, making a conclusion about the genesis and nature of the neoplasm.

Fiberoptic bronchoscopy allows for a general examination of the bronchi and the collection of material for cytological examination.

Mediastinoscopy is a method designed to examine the lymph nodes of the mediastinum. In this study, the endoscope is inserted through an incision above the jugular notch of the sternum or in the parasternal region between the 1st and 3rd ribs. Only the anterior mediastinum is examined in this way.

Thoracoscopy is performed through a small incision in the intercostal space, through which an endoscope is inserted into the chest cavity to examine the parietal and visceral pleura and the surface of the lung. The method allows for the detection and verification of tumors and small metastatic nodes on the pleura, and for performing a marginal biopsy of the lung tissue.

Endoscopic retrograde cholangiopancreatography and bronchography are diagnostic X-ray endoscopic procedures used for endoscopic contrasting of the organs being examined.

Endoechography is the use of an ultrasound probe at the distal end of an endoscope, which provides unified information about the wall of a hollow organ and surrounding tissues, capturing changes with a diameter of 2-3 mm. Before surgery, this method is used to determine the extent of metastases of regional lymph nodes in gastric cancer, the degree of invasion.

Endoscopic optical coherence tomography is an optical cancer screening technique that involves obtaining high-resolution cross-sectional images of body tissues, providing the ability to obtain morphological information at the microscopic level.

Lab testing for cancer

This cancer examination is mandatory to determine the general somatic condition of cancer patients at all stages of diagnosis and treatment. However, there are currently no reliable specific laboratory tests to establish a tumor disease.

Changes in peripheral blood parameters, biochemical, and immunological data in a cancer patient are caused not by the presence of a tumor, but by the dysfunctions of organs and systems that it causes with its presence.

Changes in peripheral blood in cancer patients are also non-specific: there may be an increase in ESR over 30 mm/h, leukopenia or leukocytosis, lymphopenia, thrombocytopenia or thrombocytosis, anemia.

Various disturbances in the rheological properties of blood are possible: fluctuations in blood viscosity, aggregation of erythrocytes, which can cause hypercoagulation.

Specific biochemical changes in the body of cancer patients have not been identified either. However, with certain tumor localizations, some biochemical shifts can be noted: with primary liver cancer - increased alkaline phosphatase; pancreatic cancer - increased enzymes (lipase, amylase, alkaline phosphatase); mechanical jaundice - increased activity of aldolase, aminotransferases; prostate cancer - high levels of acid phosphatase.

Hypercalcemia is possible in breast, kidney, ovarian cancer, and non-small cell lung cancer.

With increased catabolism and decreased detoxification capabilities in malignant neoplasms, endotoxins accumulate in the body, which have a damaging effect on organs and systems. Metabolic disorders lead to the release of proteolytic enzymes into the blood and the formation of so-called medium-molecular peptides. Hyperfermentation and medium-weight molecules are the main factors of intoxication, which, in particular, causes the development of anemia.

Immunological tests usually reveal suppression of the immune response, primarily the T-cell link, characterized by a decrease in the total number of T-lymphocytes, active T-lymphocytes, and T-helpers. Oncological disease primarily develops against the background of immunodepression and secondarily aggravates it in the process of progression. Suppression of the immune system can be facilitated by all types of specific treatment measures: surgical intervention, chemoradiation therapy.

Determination of tumor markers

Currently, there is no single test that can determine the presence of a specific tumor in the human body, but tumor markers can be used to determine the presence of a tumor in the body in general. Malignant growth markers include substances of various natures: antigens, hormones, enzymes, glycoproteins, proteins, metabolites. Since the concentration of markers correlates with the mass of tumor tissue, they are usually used to assess the results of treatment. According to most researchers, tumor markers are not informative for early diagnosis of the tumor process.

The most frequently used markers are tumor-associated antigens, which include CA 125 (for diagnosis, differential diagnosis and monitoring of the effectiveness of treatment of ovarian cancer), CA 19-9 (for pancreatic and colon cancer), prostate-specific antigen (PSA) (for diagnosis, assessment of the effectiveness of treatment and dynamic monitoring of patients with prostate cancer).

Oncofetal antigens include alpha-fetoprotein (used for diagnosis and evaluation of the effectiveness of treatment of primary liver cancer and testicular cancer), carcinoembryonic antigen or carcinoembryonic antigen (CEA) - for evaluation of the effectiveness of treatment of colon, stomach, and breast cancer.

Monitoring the level of tumor marker concentration in the blood provides an idea of the radicality of treatment measures, the possible relapse of the disease, which allows them to be used in dynamic monitoring of cancer patients during treatment and subsequently - throughout their entire subsequent life.

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Morphological examination for cancer

In modern oncology, the nature of the pathological process is determined with the obligatory use of morphological methods. An oncological diagnosis must always be verified morphologically.

Cytological examination for cancer has acquired particular importance at present, allowing for quick and effective verification of the process without surgical intervention.

Since the late 1960s, cytological diagnostics has become widespread in various fields of medicine, primarily in oncology and surgery.

Clinical practice has proven the high information content of the cytological method. The coincidence of cytological and histological conclusions for tumors of the main localizations reaches 93 - 99%. Supplementing and enriching traditional pathohistological research, the cytological method has its own specifics and advantages, primarily because the object of the study is not tissues, but cells, which are easy to obtain without surgical intervention in relatively simple ways: tissue puncture with a thin needle, taking scrapings or prints from the surface of the pathological formation, etc. This eliminates the risk of organ damage and makes almost all anatomical formations available for research.

For tumors of external localization, incisional or excisional biopsy, diagnostic puncture, scraping, and imprints from the surface of ulcers and wounds are used.

Informative material for cytological examination can be obtained using exfoliative biopsy when examining pathological secretions: sputum, urine, ascitic and pleural fluids, independent discharge from the nipple of the mammary gland, etc.

With the advent of endoscopic technology, internal organs (stomach, intestines, lungs, genitals, etc.) became accessible for biopsy during diagnostic procedures (gastroscopy, laparoscopy, bronchoscopy, colonoscopy).

There are five stages of morphological diagnostics in oncology.

The first stage (outpatient) based on cytological examination allows to form three groups of patients: 1) with benign processes; 2) with suspected cancer; 3) with malignant neoplasms.

The second stage (clinical diagnostics) is intended to clarify the parameters of the already identified tumor (histotype, degree of differentiation, presence of metastases in regional lymph nodes, determination of the nature of exudates, etc.). These indicators are decisive in choosing the optimal treatment plan (surgery, preoperative or independent radiation therapy, chemotherapeutic or hormonal effects).

The third stage (intraoperative) is important in all respects. Express intraoperative cytological examination helps to solve several issues:

• determine the anatomical form of tumor growth;
• verify the spread of the tumor process to neighboring organs;
• examine all regional lymph nodes;
• by studying the imprints from the edges of the resected organ, to form an objective idea of the radicality of the surgical intervention;
• by examining the prints from the bottom and edges of the wound to determine the ablastic nature of the surgical operation.

Express cytological examination for cancer facilitates morphological verification and objective clarification of the stage of the disease already during surgery, which ensures timely and adequate volume of surgical treatment.

The fourth stage (postoperative), at which a planned histological examination of the removed specimen is performed, allows us to establish:

• tumor histotype;
• degree of malignancy and differentiation;
• the degree of tumor invasion into the organ;
• damage to regional lymph nodes;
• the state of immunogenic zones in the lymph nodes;
• the degree of pathomorphism after radiation or drug treatment.

The fifth stage (during the rehabilitation period) uses cytological examination for cancer, which facilitates early detection of disease progression in the form of relapses and metastases.

Thus, if seals are detected in the area of a previously performed operation or if regional or supraregional lymph nodes are enlarged, a diagnostic puncture is performed. Morphological control is performed at any visit of an oncological patient to a doctor. Patients operated on for stomach and intestinal cancer regularly undergo endoscopic examination with biopsy of suspicious areas.