Central lung cancer is a malignant tumor that affects large bronchi, up to the subsegmental branches. Early symptoms of central lung cancer include cough, hemoptysis, shortness of breath; late symptoms are associated with complications: obstructive pneumonia, ERW syndrome, metastases. Verification of the diagnosis is carried out by X-ray and CT of the lungs, bronchoscopy with targeted biopsy, spirometry. In operable cases, the treatment of central lung cancer is surgical, radical (the volume of resection from lobectomy to extended or combined pneumonectomy), supplemented by postoperative radiation therapy, chemotherapy.
C34 Malignant neoplasm of the bronchi and lung
Central lung cancer is a bronchogenic cancer with intra- or peribronchial growth originating from the proximal parts of the bronchial tree – the main, lobular or segmental bronchi. This is the most common clinical and radiological form of the disease, accounting for up to 70% of lung cancer (peripheral lung cancer accounts for about 30%). However, if peripheral cancer is more often detected with preventive fluorography, even before the onset of symptoms, then central cancer is mainly due to the appearance of complaints. This leads to the fact that every third patient with central lung cancer, who independently turned to a doctor, is already inoperable.
Men develop lung cancer 8 times more often than women. At the time of detection of the tumor, the age of patients usually ranges from 50 to 75 years. Lung cancer is the most urgent problem of clinical pulmonology and oncology, which is due both to its high specific gravity in the structure of cancer incidence, and to a steady increase in cases of pathology.
All factors affecting the incidence of central lung cancer are divided into genetic and modifying. The criteria of genetic predisposition are 3 or more cases of lung cancer in the family, the presence of a patient with polyneoplasia syndrome – primary multiple malignant tumors.
Modifying factors can be exogenous and endogenous; most of them are potentially preventable. Significant exogenous factors are:
- smoking: daily smoking of one pack of cigarettes increases the risk of central lung cancer by 25 times and mortality by 10 times.
- the effect on the bronchial epithelium of environmental carcinogens (polyaromatic hydrocarbons, gases, resins, etc.), industrial pollutants (fertilizers, acid and alkali vapors, arsenic, cadmium, chromium).
- ionizing radiation has a systemic effect on the body, increasing the risk of developing malignant neoplasms.
Male gender and age over 45 are considered to be unavoidable risk factors. The most important endogenous causes include:
- chronic pneumonia (chronic pneumonia, chronic bronchitis, pneumofibrosis, etc.);
- pulmonary tuberculosis.
Usually, central lung cancer develops against the background of bronchial mucosal dysplasia, so it is not surprising that over 80% of the patients are heavy smokers, and 50% suffer from chronic bronchitis.
According to the clinical and anatomical classification, central lung cancer is divided into endobronchial (endophytic and exophytic), peribronchial nodular and peribronchial branched. According to the histomorphological features of the structure, squamous cell (epidermal), small cell, large cell cancer, lung adenocarcinoma and other rare forms are distinguished. In 80% of cases, central lung cancer is verified as squamous. In the American classification of central lung cancer , there are 4 stages of the oncoprocess:
- Stage 1 – tumor diameter up to 3 cm, localization at the level of segmental bronchus; there are no signs of metastasis.
- Stage 2 – tumor diameter up to 6 cm, localization at the level of the lobar bronchus; there are single metastases in bronchopulmonary lymph nodes.
- Stage 3 – the diameter of the tumor is more than 6 cm, there is a transition to the main or other lobar bronchus; there are metastases in tracheobronchial, bifurcation, paratracheal lymph nodes.
- Stage 4 – the spread of the tumor beyond the lung with the transition to the trachea, pericardium, esophagus, diaphragm, large vessels, vertebrae, chest wall. Cancerous pleurisy, multiple regional and distant metastasis are determined.
The clinic of the disease is characterized by three groups of symptoms: primary (local), secondary and general. The primary symptoms are among the earliest; they are caused by the infiltration of the bronchial wall by the tumor and a partial violation of its patency. Usually, a dry cough appears first, the intensity of which is more pronounced at night.
As the bronchial obstruction increases, mucous or mucopurulent sputum appears. In half of the patients, hemoptysis occurs in the form of streaks of scarlet blood; less often, central lung cancer manifests with pulmonary bleeding. The severity of shortness of breath depends on the caliber of the affected bronchus. Chest pains are typical both on the affected and the opposite side.
Secondary symptoms reflect complications associated with central lung cancer. Such complications may include obstructive pneumonia, compression or germination of neighboring organs, regional and distant metastasis. With complete obturation of the bronchial lumen by a tumor, pneumonia develops, which often has an abscessing character. At the same time, the cough becomes moist, sputum – abundant and purulent. Body temperature rises, chills occur, signs of intoxication increase. Shortness of breath worsens, reactive pleurisy may develop.
Common symptoms in central lung cancer are associated with cancer intoxication and concomitant inflammatory changes. They include malaise, fatigue, decreased appetite, weight loss, subfebrility, etc. Usually they join already in common stages. In 2-4% of patients, paraneoplastic syndromes are detected: coagulopathy, arthralgia, hypertrophic osteoarthropathy, migrating thrombophlebitis, etc.
In the case of germination of intra-thoracic structures, chest pains increase, mediastinal compression syndromes and superior vena cava syndrome may develop. The widespread nature of central lung cancer may be indicated by hoarseness of voice, dysphagia, swelling of the face and neck, swelling of the cervical veins, dizziness. In the presence of distant metastases in the bone tissue, pain in the bones and spine, pathological fractures appear. Metastasis to the brain is accompanied by intense headaches, motor and mental disorders.
Central lung cancer often occurs under the guise of recurrent pneumonia, therefore, in all suspicious cases, an in-depth examination of the patient by a pulmonologist with a complex of radiological, bronchological, cytomorphological studies is required. During the general examination, attention is paid to the condition of peripheral lymph nodes, percussion and auscultative signs of ventilation disorders. The survey algorithm includes:
- Radiation diagnostics. Two-projection lung x-ray is mandatory for all patients. X-ray signs of central lung cancer are represented by the presence of a globular node in the root of the lung and the expansion of its shadow, atelectasis, obstructive emphysema, increased pulmonary pattern in the root zone. Linear tomography of the lung root helps to clarify the size and localization of the tumor. CT of the lungs is informative for assessing the relationship of the tumor with the pulmonary vessels and mediastinal structures.
- Bronchial endoscopy. In order to visually detect the tumor, clarify its boundaries and take tumor tissue, bronchoscopy with biopsy is performed. In 70-80% of cases, the analysis of sputum for atypical cells, cytological examination of flushing from the bronchi is informative.
- FER. Based on spirometry data, it is possible to judge the degree of bronchial obstruction and respiratory reserves.
In the central form of lung cancer, differential diagnosis is carried out with infiltrative and fibrous-cavernous tuberculosis, pneumonia, lung abscess, BEB, bronchial foreign bodies, bronchial adenomas, mediastinal cysts, etc.
The choice of treatment method depends on its stage, histological form, concomitant diseases. For this purpose, surgical, radiation and chemotherapeutic methods, as well as their combinations, are used in oncology.
Contraindications to the operation can be a significant prevalence of the oncoprocess (inoperable), low functional indicators of the cardiovascular and respiratory systems, decompensation of concomitant pathology. Radical operations for central lung cancer are:
- Lung resection in the volume of at least one lobe (lobectomy, bilobectomy). In the surgery of central lung cancer, wedge-shaped or circular resections of the bronchi are widely used, complementing lobectomy.
- Advanced pneumonectomy. The germination of the tumor of the pericardium, diaphragm, esophagus, vena cava, aorta, rib wall serves as the basis for a combined penvmonectomy.
In the postoperative period, patients are usually prescribed chemotherapy; a combination of surgery with subsequent radiation therapy is possible. It is known that this combination increases the 5-year survival rate of operated patients by 10%. In inoperable forms of central lung cancer, radiation or drug treatment, symptomatic therapy (analgesics, antitussive, hemostatic agents, endoscopic recanalization of the bronchial lumen) is performed.
The prognosis of survival depends on the stage of cancer and the radicality of the treatment. Among patients operated on at stage 1, 70% overcome the 5-year postoperative threshold, 45% at stage 2, and 20% at stage 3. However, the situation is complicated by the fact that the number of operable patients among those who applied independently is no more than 30%. Of these, 40% of patients require various modifications of pneumonectomy and 60% – lobectomy and bilobectomy. Postoperative mortality ranges from 3-7%. Without surgery, patients die within the next 2 years after diagnosis.
The most important areas of lung cancer prevention are mass preventive examination of the population, prevention of the development of background diseases, formation of healthy habits, exclusion of contact with carcinogens. These issues are a priority and are supported at the State level.