Lung cancer

Introduction to lung cancer Lung cancer occurs in the bronchial mucosa epithelium, also known as bronchial carcinoma. In the past 50 years, the incidence of lung cancer has been reported to increase significantly in many countries. Among male cancer patients, lung cancer has ranked first, and the incidence rate in women has also increased rapidly, accounting for the second or third place of common malignant tumors in women. The etiology of lung cancer is still not fully clear. A large amount of data indicates that long-term large amount of cigarette smoking is an important cause of lung cancer. For more than 40 cigarettes per day for many years, the incidence of lung squamous cell carcinoma and undifferentiated carcinoma is 4 to 10 times higher than that of non-smokers. The incidence of lung cancer in urban residents is higher than in rural areas, which may be related to air pollution and carcinogens in smoke. Therefore, it should promote non-smoking and strengthen urban environmental sanitation. basic knowledge The proportion of sickness: 0.5% (the incidence of smoking in men is extremely high) Susceptible people: Most of them are male, the male to female ratio is about 4-8:1, and the patients are mostly over 40 years old. A patient with a history of smoking. Mode of infection: non-infectious Complications: atelectasis pneumonia, thoracic empyema, arrhythmia, heart failure, respiratory failure

Cause of lung cancer

Smoking (20%):

In 1922, Hampeln found that continuous smoking and inhalation of dust can stimulate the bronchial epithelium to induce cancer. In 1924, Moller applied tar to the back of the rabbit and found that the incidence of lung cancer increased slightly. It is currently considered that smoking is the most basic risk factor for lung cancer. There are more than 3,000 kinds of chemicals in tobacco. Multi-chain aromatic hydrocarbons (such as benzopyrene) have strong carcinogenic activity and can act on some special enzymes in human tissues (especially lung tissues) to produce cells. Mutations in molecular structures (such as DNA) may have mutations in K-ras.

Occupational and environmental exposure (10%):

It is estimated that up to 15% of lung cancer patients have a history of environmental and occupational exposure, and there is sufficient evidence to confirm that the following nine industrial ingredients increase the incidence of lung cancer: by-products of aluminum products, arsenic, asbestos, bis-chloromethyl ether, chromium compounds, coke ovens, Mustard gas, nickel-containing impurities, vinyl chloride, long-term exposure to strontium, cadmium, silicon, formalin and other substances will also increase the incidence of lung cancer. In addition, air pollution, especially industrial waste gas, is a high risk factor for lung cancer.

Radiation (20%):

Uranium and fluorspar miners are exposed to inert gas helium, decaying uranium by-products, etc., which are significantly higher than other people's lung cancer, but people with ionizing radiation do not increase lung cancer.

Chronic lung infection (15%):

In patients with tuberculosis, bronchiectasis, etc., the bronchial epithelium may become squamous in the process of chronic infection, eventually causing cancer, but such cases are rare.

Intrinsic factor (5%):

Family, genetic and congenital factors as well as decreased immune function, metabolism, and endocrine dysfunction may also be risk factors for lung cancer.

Air pollution (10%):

The incidence of lung cancer in industrialized countries is high, the city is higher than the rural areas, and the factory mining area is higher than the residential area. The main reason is that the industrial and transportation developed areas, oil, coal and internal combustion engines, and the asphalt roads contain dust and benzopyrene-induced carcinogenesis. Hazardous substances such as hydrocarbons pollute the atmosphere. The survey materials indicate that the incidence of lung cancer is also high in areas with high concentrations of benzopyrene in the atmosphere. Air pollution and the incidence of tobacco smoke on lung cancer may promote each other and play a synergistic role.

Pathogenesis

There are four ways to transfer lung cancer:

1. Direct diffusion

The cancer grows, blocking the bronchial lumen, and also expanding into the extrapulmonary lung tissue. Tumors near the periphery of the lung can invade the pleura and chest wall. Central or near the mediastinum can invade the pleura and chest wall, central type or Tumors close to the mediastinum can invade other organs, and large tumors can undergo central ischemic necrosis and form cancerous cavities.

2, blood transfer

It is a late manifestation of lung cancer. Cancer cells can be transferred to any part of the body after returning to the left heart with the pulmonary veins. The common metastatic sites are liver, brain, lung, bone system, adrenal gland, kidney and pancreas.

3, intrabronchial dissemination

In cases of alveolar cell carcinoma, cancer cells on the bronchioles and alveolar walls are easily detached; cancer cells can diffuse through the bronchial tubes into adjacent lung tissues to form new cancerous foci.

4, lymphatic metastasis

The lymphatic drainage of the lung has a certain rule. The right upper lobe flows to the right hilar and right upper mediastinal lymph nodes. The right middle lobe flows to the middle and lower lobe. The lymph nodes in the lower lobe, the subcarinal and right upper mediastinal lymph nodes, and the right lower lobe lead to the middle and lower Leaf summary area, subcarinal ligament, lower lung ligament and right upper mediastinal lymph node, left upper lobe leading to aortic arch (Bottallo) lymph node, left anterior superior mediastinal lymph node, left lower lobe lymph flow up and down leaf summary area, subcarinal and leaping The mediastinum to the right superior mediastinal lymph node, such as the lymph node metastasis (N state) of the lymph node lung cancer with Maoshof, can be shown.

Histological classification of lung cancer: The main pathological types of lung cancer are divided into two categories: small cell lung cancer and non-small cell lung cancer. WHO histopathological classification is based on light microscopy and reference group, immunohistochemistry, electron microscopy and other auxiliary examination results. .

Lung cancer prevention

1. Prohibit and control smoking

To ban and control smoking, we must first focus on reducing the proportion of smokers in the population. It is necessary to enact certain laws or regulations to restrict people, especially to limit youth smoking.

2. Control air pollution

Do a good job in environmental protection and effectively control air pollution to achieve the goal of preventing lung cancer.

3. Occupational protection

For mining areas where radioactive ore is to be mined, effective protective measures should be taken to minimize the amount of radiation received by workers. Workers exposed to carcinogenic compounds must take various effective and effective labor protection measures to avoid or reduce contact with carcinogenic factors. .

4, prevention and treatment of chronic bronchitis

Since the incidence of lung cancer in patients with chronic bronchitis is higher than that in patients without chronic bronchitis, active prevention and treatment of chronic bronchitis has certain significance in preventing lung cancer, especially to urge smokers with chronic bronchitis to quit because of chronic bronchitis. The incidence of lung cancer is higher in smokers.

5, early detection, early diagnosis and early treatment

The screening methods for early stage lung cancer are still unsatisfactory. The cost of screening lung cancer in the population is very expensive, and the possibility of reducing lung cancer mortality is very small.

The study used chemoprevention, such as the use of cyclooxygenase (COX) inhibitors, fat oxygenase inhibitors, etc. to try to block the development of carcinogenic factors, some foods rich in vitamin E, carotenoids, retinal, selenium and other foods for lung cancer It also has a preventive effect.

Lung cancer complications Complications atelectasis pneumonitis empyema arrhythmia heart failure respiratory failure

Most lung cancer patients who have had intra-thoracic regional dissemination have symptoms of chest pain, followed by hoarseness, and finally lead to facial and neck edema. Finally, lung cancer patients with regional spread have almost different degrees of gas. promote.

However, some complications are often caused after lung cancer surgery. The formation of the lung cancer is closely related to the factors of the patient's body and the scope of the operation. The common postoperative complications and prevention methods are as follows:

1, respiratory complications

Such as sputum retention, atelectasis, pneumonia, respiratory insufficiency, etc., especially in the elderly and infirm, the original chronic bronchitis, emphysema, the incidence is higher, due to wound pain after surgery, patients can not do effective cough, The sputum retention causes airway obstruction, atelectasis, and respiratory insufficiency. The prevention is that the patient can fully understand and cooperate, and actively prepare for the operation. After the operation, encourage and urge the patient to take deep breath and force cough to effectively drain the sputum. If necessary, nasal catheter suction or bronchoscopy suction, pneumonia should be active anti-inflammatory treatment, when respiratory failure, mechanically assisted breathing is often required.

2, postoperative hemothorax, empyema and bronchial pleural fistula

The incidence rate is very low. Postoperative hemorrhage is a serious complication. It must be treated urgently. If necessary, the chest should be stopped again to stop bleeding. When the lung surgery is performed, the bronchus or lung secretions contaminate the chest and the empyema. In addition to the selection of effective antibiotics, timely and thorough thoracentesis is extremely important. Patients with poor results may consider closed thoracic drainage, residual bronchial stump cancer after pneumonectomy, hypoproteinemia and improper operation. After the operation, the bronchial stump is poorly healed or the fistula is formed. In recent years, the occurrence of such complications has been greatly reduced.

3, cardiovascular system complications

Old and frail, intraoperative mediastinal and hilar traction, low potassium, hypoxia and hemorrhage often become the cause, common cardiovascular complications include postoperative hypotension, arrhythmia, pericardial tamponade, heart failure, etc. For elderly patients, there are heart diseases before surgery. The indications for surgery with low cardiac function should be strictly controlled. The operator pays attention to the operation, keeps the airway open and adequate oxygen supply after surgery, closely observes blood pressure, pulse changes, and timely supplements blood volume. After the operation, the infusion rate should be slow, balanced, prevent too fast, excessively induce pulmonary edema, and at the same time, for ECG monitoring, once abnormalities are found, according to the condition, the elderly patients are often accompanied by recessive coronary heart disease, a variety of surgical trauma Stimulation can prompt an acute attack, but it can be turned safe under the strict supervision and timely treatment of the clinician.

Symptoms of lung cancer Common symptoms Bronchial tree compression sputum with bloody dry cough chest pain fever with cough, slightly... Planting disseminated lung small nodules cough with weight loss hemoptysis with skin and mucous membrane bleeding thick or purulent phlegm. ..

Most of the lung cancer patients are male, the ratio of male to female is about 4-8:1, and the majority of patients are over 40 years old.

The clinical manifestations of lung cancer are closely related to the location, size, oppression of the cancer, invasion of adjacent organs, and the presence or absence of metastasis. Early lung cancer, especially peripheral lung cancer, often does not produce any symptoms, mostly found during chest x-ray examination. After a cancer grows in a large bronchus, it often produces a irritating cough. Most of them have a paroxysmal dry cough or only a small amount of white foam. It is easy to mistake the cold. When the cancer continues to grow and affect the bronchial drainage, secondary pulmonary infection, there may be purulent sputum, the amount of sputum is also increased. Another common symptom is blood stasis, usually a small amount of hemoptysis in the sputum with blood spots, bloodshot or intermittent, and a large amount of hemoptysis is rare. Some lung cancer patients may have chest suffocation, wheezing, shortness of breath, fever and mild chest pain in the clinic due to the large bronchial obstruction caused by the tumor.

When advanced lung cancer oppresses a nearby organ or invades a distant metastasis, the following symptoms can occur:

1. Oppression or invasion of the phrenic nerve causes paralysis of the ipsilateral diaphragm.

2, oppression or violation of the recurrent laryngeal nerve, causing vocal cord paralysis, hoarse voice.

3, oppression of the superior vena cava, the bow g face, neck, upper limbs and upper chest vein engorgement, tissue edema, upper limb venous pressure increased.

4, invading the pleura, can cause pleural effusion, often bloody. A large amount of fluid can cause shortness of breath. In addition, cancer invading the pleura and chest wall can cause persistent severe chest pain.

5, cancer invades the mediastinum, oppression of the esophagus, can cause difficulty swallowing.

6, the top of the upper lobe, can invade and oppress the organ tissue located in the upper thoracic cavity. Such as the first rib, subclavian arteriovenous, brachial plexus, cervical sympathetic nerve, etc., resulting in severe chest pain, upper extremity venous engorgement, edema, arm pain and upper limb dyskinesia, ipsilateral upper eye face drooping, pupil diminution, eyeball retraction Cervical sympathetic syndrome such as no sweat on the face. After the lung cancer has been transferred to the bloodstream, different symptoms are caused by invading the organ.

7, in addition, there are a small number of lung cancer cases, due to cancer to produce endocrine substances, clinically presented non-metastatic systemic symptoms, such as osteoarthritis syndrome (skull finger, bone and joint pain, periosteal hyperplasia, etc.), Cushing Symptoms, myasthenia gravis, male mammary gland enlargement, multiple muscle neuralgia, etc. These symptoms may disappear after removal of a lung cancer.

Lung cancer check

Laboratory inspection

1, sputum exfoliative cytology

It is simple and easy to perform, but the positive detection rate is only 50% to 80%, and there is a false positive of 1% to 2%. This method is suitable for censuses in high-risk groups, as well as isolated images in the lungs or diagnosed with unexplained hemoptysis.

2, percutaneous lung puncture cytology

Adapted to peripheral lesions and not suitable for thoracotomy for various reasons, other methods failed to establish a histological diagnosis. At present, it is preferred to use a fine needle in combination with CT, which is safer to operate and has fewer complications. The positive rate was 74% to 96% in malignant tumors and 50% to 74% in benign tumors. Complications include pneumothorax 20% to 35% (about 1/4 of which need to be treated), a small amount of hemoptysis 3%, fever 1.3%, air embolism 0.5%, and needle implant 0.02%. Thoracic surgery has fewer applications because of thoracoscopic examination and thoracotomy.

3, thoracic puncture cytology

Patients suspected or diagnosed with lung cancer may have pleural effusion or pleural dissemination, and cell analysis of pleural effusion by thoracentesis may be clearly staging, and in some cases, a diagnosis basis may be provided. For lung cancer with pleural effusion, bronchoalic adenocarcinoma has the highest detection rate, and its positive rate of cytological diagnosis is 40% to 75%. If the cytological analysis of the pleural effusion obtained by puncture cannot be diagnosed, consider further examinations such as thoracoscopic surgery.

4, scalene and supraclavicular lymph node biopsy

For patients with lung cancer, routine biopsy can not be affected by the scalene or supraclavicular lymph nodes, rarely found metastases, patients with spastic bone lymph nodes, the diagnosis rate is nearly 90%. Biopsy occasionally sees complications such as pneumothorax and major bleeding. Even if there are few complications, FNAB (fine needle aspiration biopsy) is recommended for cases of lymph nodes that can be touched on the scalene or clavicle. Surgical biopsy. Routine histology and appropriate immunohistochemistry are helpful in the diagnosis of cell typing.

5, serum tumor markers

A number of serum tumor markers associated with lung cancer have been identified, which may indicate an increase in carcinogenic factors or a degree of "detoxification" of certain carcinogens. Serum tumor markers of lung cancer may be valuable indicators for tumor staging and prognosis analysis and can be used to evaluate treatment outcomes. Tumor marker test results must be combined with other test results and cannot be used alone to diagnose cancer.

6, monoclonal antibody scanning

The use of monoclonal antibody screening, diagnosis and staging is currently an experimental field. Immunofluorescence images of anti-carcinoembryonic antigen MoAb labeled with radioactive substances have been reported. Currently, 111In or 99Tc are commonly used for labeling, respectively 73%. Primary tumors and 90% of secondary tumors absorb radiolabeled antibodies, and antibody uptake is also imaged by tumor size and location.

Film degree exam

1, X-ray diagnosis

For the most common means of diagnosing lung cancer, the positive detection rate can reach more than 90%. The earlier X-ray findings of lung cancer were: 1 isolated spherical shadow or irregular small infiltration. 2 The unilateral ventilation was poor when deep inhalation under fluoroscopy, and the mediastinum moved slightly to the affected side. 3 Localized emphysema occurred in the expiratory phase. 4 The mediastinum swing occurs during deep breathing. 5 If the lung cancer progresses in the blocked segment or the leaf bronchus, the gas at the distal end of the blockage gradually absorbs the segmental atelectasis. Such a defect such as concurrent infection forms pneumonia or lung abscess. More advanced lung cancer can be seen: lung field or hilar mass tumor nodules, no calcification, lobulated, uniform density, burr at the edges, peripheral vascular texture distortion, sometimes central liquefaction, thick wall, eccentricity, uneven inner wall Empty. The doubling time is short. When the tumor obstructs the leaf or the total bronchi, the lobes or total atelectasis appear. When the pleura is involved, a large amount of pleural fluid can be seen. When the chest wall is invaded, rib damage can be seen.

2, CT examination

In the diagnosis and staging of lung cancer, CT examination is the most valuable non-invasive examination. CT can find the location and cumulative range of the tumor, and can also roughly distinguish its benign and malignant.

Diagnosis and diagnosis of lung cancer

diagnosis

The diagnosis of primary bronchogenic carcinoma includes: symptoms, signs, x-ray findings, and sputum cancer screening (sick examination). In the diagnosis work, different steps should be taken according to different situations.

1. X-ray negative, negative test

1. Anyone who is asymptomatic but has three high-risk factors (male, age 45 years old and smoking>400/year) should undergo 70-100mm fluorescent microscopy x-ray or chest fluoroscopy and sputum cell examination for half a year.

2, where there are hemoptysis or / and dry cough, accompanied by three high-risk factors should be repeated sputum cytology examination, while giving regular anti-inflammatory treatment; can be considered for fiberoptic bronchoscopy (fibrous bronchoscopy) and television Perspective, such as repeated sputum examination or microscopic examination is still negative, should be reviewed every two months, adhere to one year.

Second, X-ray negative, positive test

1. Exclude upper respiratory tract and esophageal cancer.

2, the fiberoptic bronchoscopy, for the glimpse of the sub-Asian segment, in case of suspicious local mucosal thickening, rough or bloody, must be brushed there, rinse or puncture the bronchial wall mucosa to find cancer cells, if found locally High or low unevenness or rough, should be considered for bite biopsy.

3, to conduct TV perspective, change position, focus on concealed parts of small knots.

4. If the lesions are not found through the above examinations, the sputum should still be reviewed every two months. Electrodialysis and fiberoptic bronchoscopy can also be used for CT examination. The suspicious area should be used as a subdivision layer. Regular review should last no less than One year.

Third, X-ray positive, negative test

1, there are segments, leaf pneumonia or obstructive pneumonia, suspected of central lung cancer should be used for fiberoptic bronchoscopy, including fiberoptic bronchoscopy biopsy (TBB), or selective bronchography; and repeated enhancement of sputum examination.

2, lump or nodular lesions should be used as a partial tomography, if necessary, can be used for bronchoscopy lung biopsy (TBLB), or percutaneous lung biopsy, or aspiration for cytological diagnosis.

3. Continuous inspection for at least 12 times.

4, repeated sputum examination is still negative, and x-ray is highly suspected of lung cancer, should be used for thoracotomy and cryosection biopsy.

Fourth, X-ray positive, positive test

1. Active preparation before surgery.

2, suspected regional lymph node enlargement, you can take a positive lateral oblique layered slice, if necessary, can be used for CT, for limited small cell lung cancer in large hospitals should be routinely used CT and positive oblique layered tablets, liver B-ultrasound Bone isotope scanning and bone marrow puncture into a biopsy smear to facilitate the development of a treatment plan.

Differential diagnosis

1. Tuberculosis

In particular, tuberculoma (ball) is sometimes difficult to distinguish from peripheral lung cancer. Tuberculoma (ball) is more common in young patients under 40 years of age, with a longer course of disease, less blood stasis, less erythrocyte sedimentation rate, 16% to 28% Tuberculosis is found in the patient's sputum. The chest radiograph is mostly round. It is found in the tip or posterior segment of the upper lobe. It is small in size and generally does not exceed 5 cm in diameter. The boundary is smooth and the density is uneven. Calcification can be seen. In 16% to 32% of cases, the drainage bronchus can be seen. The shadow points to the hilar, less pleural shrinkage, slower growth, such as hollowing in the center liquefaction, more central thin wall and smooth inner edge, tuberculosis (ball) around there are often scattered tuberculosis lesions called satellite stoves, peripheral type Lung cancer is more common in patients over 40 years old, with more blood in the sputum, 40% to 50% of cancer cells in the sputum, X-ray chest radiographs often lobulated, irregular edges, small burr and pleural wrinkles Contraction, rapid growth, in some cases of chronic tuberculosis, lung cancer can occur on the basis of tuberculosis, so in adult patients with chronic tuberculosis, if there is abnormal clumping in the lungs, increased hilar shadows or regular anti-tuberculosis drugs, Lesion is missing Improved but when income increases, the possibility of lung cancer should be suspected, sputum cytology and must make further bronchoscopy, perform exploratory thoracotomy if necessary.

2, lung inflammation

Bronchial pneumonia in elderly patients is sometimes difficult to distinguish from obstructive pneumonia caused by obstruction of bronchial lung cancer. Obstructive pneumonia often has a fan-shaped distribution according to bronchial branches, while general bronchopneumonia has irregular flaky shadows, but multiple episodes such as pneumonia The site should be vigilant. It should be highly suspected of tumor blockage. The patient's sputum should be taken for cytological examination and fiber light-guided vascular examination. In some cases, the lung inflammation is partially absorbed, and the remaining inflammation is wrapped by fibrous tissue. When forming nodules or inflammatory pseudotumors, it is difficult to distinguish from peripheral lung cancer. In suspicious cases, lobectomy should be performed to avoid delay in treatment.

3, benign lung tumors and bronchial adenoma

Benign lung tumors such as structural tumors, chondromas, fibroids, etc. are rare, but they must be differentiated from peripheral lung cancer. Generally, benign tumors have a longer course and slower growth, and most of them have no symptoms in clinical practice. X-rays are often used. It has a round shadow with neat edges, no burrs, and no lobulated shape. Bronchial adenoma is a low-grade malignant tumor, often occurring in younger women, mostly from larger bronchial mucosa. Therefore, clinically, there are symptoms of pulmonary infection and hemoptysis caused by bronchial obstruction, which can often be diagnosed by fiber bronchoscopy.

4, mediastinal malignant lymphoma (lymphosarcoma and Hodgkin's disease)

Clinically, there are often symptoms such as cough and fever. X-ray films show a widening of the mediastinum and are lobulated. Sometimes it is difficult to distinguish it from central lung cancer. If there is swelling on the supraclavicular or axillary lymph nodes, adopt living tissue for pathology. Slices can often be diagnosed. Lymphosarcoma is particularly sensitive to radiation therapy. For suspicious cases, small doses of radiation therapy can be tried. When the temperature reaches 5-7 Gy, the mass can be significantly reduced. This experimental treatment also contributes to the diagnosis of lymphosarcoma. .

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