Bronchial cancer is a malignant neoplasm that develops from the integumentary epithelium of the bronchi of various calibers and bronchial glands. With the development of this disease, the patient is concerned about cough, shortness of breath, hemoptysis, fever of the remitting type. Diagnosis involves X-ray, tomographic and bronchological examination, cytological or histological confirmation of the disease. Depending on the stage, surgical treatment may consist of lobectomy, bilobectomy or pulmonectomy; in inoperable processes, radiation and chemotherapy are performed.
C34 Malignant neoplasm of the bronchi and lung
Bronchial cancer (bronchogenic cancer) and lung cancer (alveolar cancer) in pulmonology are often combined by the general term “bronchopulmonary cancer”. Primary malignant tumors of the lungs and bronchi account for 10-13% of all oncopathology, second in frequency only to stomach cancer. Pathology usually develops at the age of 45-75 years; at the same time, men are 6-7 times more likely than women.
In recent decades, there has been an increase in the incidence of bronchogenic cancer due to increased carcinogenic effects. At the same time, it is impossible not to note the progress in the early diagnosis of disease associated with the widespread introduction of endoscopic methods into clinical practice, expanding the possibilities of thoracic surgery in the issue of radical treatment of bronchopulmonary cancer, increasing the life expectancy of patients.
Causes of bronchial cancer
In the structure of the causes of bronchial cancer, smoking is the most significant etiological factor. When smoking 2 or more packs of cigarettes a day, the risk of developing bronchopulmonary cancer increases by 15 to 25 times. Long-term regular inhalation of tobacco smoke containing many carcinogens causes metaplasia of the epithelium of the bronchial mucosa. In addition, bronchial mucus secretion increases, in which harmful microparticles accumulate, chemically and mechanically irritating the mucous membrane. Under these conditions, the ciliated epithelium of the bronchi does not cope with the effective cleansing of the respiratory tract.
The risk of bronchial cancer is increased in people working in hazardous industries associated primarily with asbestos, nickel, chromium, arsenic, coal dust, mustard gas, mercury, etc. Often the causes of bronchial cancer are inflammatory lesions of the respiratory tract of a chronic nature: bronchitis, bronchiectasis, pneumonia, pulmonary tuberculosis, etc.
Pathogenesis of bronchial cancer
A decrease in the activity of metabolic and enzymatic processes aimed at neutralizing and removing harmful substances from the outside, the formation of endogenous carcinogens in combination with a violation of trophic innervation causes the development of a blastomatous process in the bronchi.
The complex of pathological changes in bronchial cancer depends on the degree of violation of bronchial patency. First of all, changes develop with epdobronchial tumor growth, leading to narrowing of the bronchial lumen, later – with peribronchial growth, accompanied by compression of the bronchus from the outside.
Bronchial obstruction or compression is accompanied by the development of hypoventilation, and with complete closure of the bronchus – atelectasis of the lung area. Such disorders can lead to infection of a section of lung tissue turned off from gas exchange with the formation of a secondary abscess or gangrene of the lung. With ulceration or necrosis of the tumor, less or more pronounced pulmonary bleeding occurs. The collapse of the tumor can lead to the formation of a bronchopesophageal fistula.
From the point of view of histological structure, there are squamous cell bronchial cancer (60%), small cell and large cell bronchial cancer (30%), adenocarcinoma (10% of cases). According to the clinical and anatomical classification, there are central and peripheral bronchogenic cancers. In 60% of cases, there is a central cancer growing from large bronchi (main, lobular, segmental); in 40% – peripheral bronchial cancer affecting the subsegmental bronchi and bronchioles.
Central bronchial cancer can have an endobronchial nodular, peribronchial nodular or peribronchial branched (infiltrative) form. Peripheral bronchopulmonary cancer occurs in nodular, abdominal and pneumonia-like forms.
By the nature of growth, exophytic cancer is isolated, growing into the lumen of the bronchus; endophytic, growing in the direction of the pulmonary parenchyma; and mixed. Bronchial cancer with exophytic growth causes hypoventilation or atelectasis of the lung area ventilated by this bronchus; in some cases, valvular emphysema develops. The endophytic form can lead to perforation of the bronchial wall or tumor ingrowth into neighboring organs – the pericardium, pleura, esophagus.
Symptoms of bronchogenic cancer
Clinical manifestations of cancer are determined by the caliber of the affected bronchus, the anatomical type of tumor growth, its histological structure and prevalence. With central bronchial cancer, the earliest symptom is a constant dry nasal cough. Paroxysmal cough may be accompanied by wheezing, stridorous breathing, cyanosis, sputum separation with an admixture of blood. Hemoptysis and bleeding caused by the collapse of the tumor occurs in 40% of patients. When the pleura is affected (its germination by a tumor, the development of cancerous pleurisy), chest pains appear.
Complete blockage of the bronchus by the tumor leads to inflammation of the unventilated part of the lung with the appearance of obstructive pneumonitis. It is characterized by an increase in cough, the appearance of sputum, the addition of fever of a remitting nature, shortness of breath, general weakness, apathy.
In the late stages of bronchial cancer, the syndrome of the superior vena cava develops, due to a violation of the outflow of blood from the upper parts of the trunk. For ERW syndrome, swelling of the veins of the neck, upper extremities and chest is typical; puffiness and cyanosis of the face. With the development of hoarseness of the voice, one should think about the lesion of the vagus nerve; if there is pain in the heart, pericarditis – about the spread of bronchial cancer to the heart sac.
With advanced bronchial cancer, metastases are found in regional (bifurcation, peribronchial, paratracheal) lymph nodes; hematogenous and lymphogenic metastasis occurs in the liver, adrenal glands, brain, bones.
At an early stage, physical examination of patients with bronchial cancer is not informative enough. With the development of atelectasis, there is a sinking of the supraclavicular region and compliant areas of the chest wall. The auscultative picture of bronchial cancer is characterized by a variety of sound phenomena up to the complete absence of respiratory noises in the atelectasis zone. The percussion sound is blunted, there is a weakening or absence of bronchophony and vocal tremor.
In case of bronchial cancer, a complete X-ray examination is carried out (lung radiography in 2 projections, X-ray and computed tomography), MRI of the lungs, which allows you to clearly visualize all the structures of interest on the images. With the help of bronchoscopy, it is possible to visually detect exophytically growing bronchial cancer, to take washing water for cytological analysis, as well as endoscopic biopsy for histological examination.
Ultrasound of the pleural cavity, pericardium, mediastinum allows you to detect signs of the germination in neighboring organs. With the development of carcinomatous pleurisy, thoracocentesis with cytology of pleural effusion is performed. To assess the prevalence of the cancer process, if necessary, a pre-calcified biopsy, skeletal scintigraphy, bone marrow biopsy, ultrasound of the liver and adrenal glands, CT of the brain is performed. At the diagnostic stage, bronchial cancer is differentiated with bronchial adenoma, bronchial foreign bodies, bronchitis.
Treatment of bronchial cancer
Surgical surgery, chemotherapy, and radiation therapy are used in the treatment of bronchial cancer. The combination and sequence of methods is determined taking into account the type and prevalence of the tumor process. Taking into account the indications in bronchial cancer surgery, partial lung resection (lobectomy and bilobectomy) or removal of the entire lung (pneumonectomy, pneumonectomy with mediastinal lymphadenectomy, circular resection of tracheal bifurcation or circular resection of the superior vena cava / thoracic aorta) is possible. In rare cases, with early detection of bronchial cancer, they are limited to circular or terminal resection of the bronchus.
With a common form of bronchial cancer, chemotherapy and radiation therapy are used in addition to surgery or as the main treatment. In the case of inoperable bronchial cancer, symptomatic treatment with antitussive and analgesic drugs, oxygen therapy is carried out.
Prognosis and prevention
The prognosis for bronchial cancer depends on the stage of detection of the disease. Radical surgical treatment allows to achieve high results in 80% of patients. With metastasis of bronchial cancer to lymph nodes, the long-term survival among operated patients is 30%. In the absence of surgical treatment of bronchial cancer, the survival rate for 5 years is less than 8%.
Measures for the prevention of bronchoalveolar cancer include mass screening of the population (fluorography), timely treatment of inflammatory processes of the bronchi, smoking cessation, the use of personal protective equipment (masks, respirators) in industries with a high degree of dust.