Primary bronchopulmonary cancer (hereafter referred to as lung cancer) is the most common primary malignant tumor of the lung. Lung cancer is currently one of the most common malignant tumors worldwide, and its incidence is increasing significantly in most countries. In the past 20 years, the global incidence of lung cancer among men and women has increased by 64.5% and 74.2%, respectively. In China, lung cancer has become the first common malignant tumor in urban areas and the third in rural areas.
The incidence of lung cancer generally rises rapidly after the age of 40, peaks at the age of 70, and decreases slightly below the age of 70. Among the known causative factors, most of them can cause lung cancer. The more important ones at present are smoking, ionizing radiation, air pollution, arsenic and other occupational factors. Early detection, early diagnosis and early treatment are important prerequisites for lung cancer to achieve good outcomes.
In Chinese medical literature, lung cancer belongs to the category of lung accumulation, Xiben, cough, wheezing, chest pain, straining cough and phlegm drink. Most of them are due to the malignant toxins offending the lung, the failure of the promotion and descent, the failure of the distribution of fluids, the formation of cancer from phlegm and stasis, and the formation of cancer that consumes qi and injures fluids.
Clinical manifestations
Symptoms: The common symptoms of lung cancer are cough, chest pain, hemoptysis, fever, etc., but they are not specific, so they make the diagnosis of lung cancer very difficult.
Cough: Due to the different growth sites, modes and speed of cancer, the cough performance of each person is different. Generally, it is not controlled by drugs. Tumor stimulates bronchial mucosa and causes cough, which is mostly dry, without sputum or with a small amount of white foamy sputum. When the tumor enlarges and causes bronchial narrowing, the cough is aggravated and is mostly persistent with a high-pitched metallic sound, which is the characteristic obstructive cough. If you have no previous history of chronic cough but this cough has an abnormal sensation and does not heal within 2-3 weeks, or if you have a previous history of chronic cough but the nature of this cough has changed or even accompanied by “bronchial sound”, you should be alert to the possibility of the existence of lung cancer.
Hemoptysis or bloody sputum: clinically, it is mostly seen as fresh blood or blood clots in the sputum, intermittently or repeatedly, rarely seen as whole mouth or large amount of blood.
Chest pain: When the tumor is located near the pleura, it is easy to produce irregular dull pain or hidden pain, which is more common in the clinic. When the tumor directly invades the pleura, especially the wall pleura, the pain is sharper and aggravated when breathing and coughing. When the ribs and thoracic vertebrae are invaded, the chest pain is severe, but it is not related to breathing and coughing, and there are often fixed pressure points.
Shortness of breath: shortness of breath due to reduction of breathing area caused by tumor development, restriction of respiratory movement or pulmonary atelectasis is understandable, but shortness of breath occurs in some early central lung cancer X-rays before a specific mass, which may be due to the infiltrative growth of tumor along the bronchial wall, causing extensive narrowing, resulting in poor ventilation. Advanced lymph node metastasis compressing large bronchus or bullae, diffuse alveolar carcinoma, pleural effusion, pericardial effusion, etc. can cause shortness of breath.
Fever: Tumor compression or obstruction of bronchus causing accumulation of secretion in distal bronchus or secondary infection is the cause of fever, generally around 38℃, rarely above 39℃, which is controlled by anti-inflammatory drugs, but can occur repeatedly. In late stage, due to necrosis of tumor tissue or absorption poisoning, anti-inflammatory treatment cannot be effective, which is not infectious in nature and is called “cancer fever”.
Other: hoarseness or hoarseness is caused by metastatic mediastinal lymph node compression or invasion of left recurrent laryngeal nerve which paralyzes the vocal cords; superior vena cava syndrome is caused by direct invasion of lung cancer or compression of superior vena cava and odd vein by mediastinal metastatic lymph nodes, which causes obstruction of blood return and produces static angina of chest wall and cervical and facial edema. The symptoms are: compression of the esophagus by enlarged lymph nodes; brachial plexus nerve compression, burning radiating pain and local sensory abnormalities in the ipsilateral upper limb, trophic muscle atrophy; cervical sympathetic nerve syndrome, the cancer invades or compresses the cervical sympathetic ganglion as shown by drooping eyelids, sunken eyes, narrow pupils, no sweating and abnormal sensation on the affected side. Phrenic nerve palsy, caused by direct tumor invasion; corresponding symptoms when metastasis to bone, liver, brain, lung, kidney, adrenal gland, subcutaneous tissue, etc.
Extra-pulmonary symptoms: They are symptoms caused by certain substances produced by some tumor cells with endocrine function that manifest outside the lungs, called extra-pulmonary symptoms. Small cell undifferentiated carcinoma of the lung and carcinoid tumor of the lung are more common in clinical practice. Common symptoms include osteoarthropathy (pestle and mortar fingers and toes and hypertrophic osteoarthropathy), endocrine disorder syndrome and neuromuscular syndrome.
Signs: Signs of lung cancer vary according to the location of the tumor and the degree of disease development. It is important to check whether there are subcutaneous nodes and enlarged lymph nodes in the whole body, and enlarged supraclavicular lymph nodes are more significant in the diagnosis. If there is limited inspiratory croup or snoring sound in the lungs, which does not disappear after coughing, it often indicates that there may be obstruction in the bronchial tubes, which is mostly seen in the early stage of central lung cancer and will disappear when the bronchial tubes are completely obstructed. Enlarged joints of limbs and pestle finger may be one of the early signs of lung cancer.
Auxiliary examination
Chest X-ray examination: X-ray examination is one of the important methods to diagnose lung cancer, including chest X-ray, chest X-ray, body layer film, etc. Central lung cancer: a) Indirect signs: Early lung cancer occurring in larger bronchi may cause different degrees of airway narrowing, resulting in a series of secondary changes, such as limited emphysema, obstructive pneumonia, pulmonary atelectasis, solid lung segments, etc. b) Direct signs: When the tumor grows to a certain extent, direct signs of tumor presence can be seen on plain films or in body films and bronchograms when the disease is early. When the tumor grows to a certain extent, the tumor can be seen on plain film or in early stage of the disease on body film or bronchography. X-ray signs of peripheral lung cancer: the lesion is irregular in shape, lobulated, with cut marks or burrs (especially fine burrs or burrs of different lengths), which is more certain when enlargement or hilar lymphatic shadow appears in dynamic observation.
Posteroanterior radiograph and lateral chest radiograph Posteroanterior chest radiograph confirms the existence of lung cancer tumor, while lateral chest radiograph is an essential supplement to posteroanterior chest radiograph, which can roughly determine the anatomical location of lobes and segments of the lesion, observe whether there is enlargement of hilar or mediastinal lymph nodes, whether there is invasion or adhesion of heart, diaphragm, interlobular pleura and aorta, and whether there is compression and damage of thoracic vertebrae.
Body layer photography: It is helpful to determine the nature of lesions, clinical staging and develop treatment plan.
Bronchography: sometimes has special significance for the diagnosis of lung cancer, which can determine the specific location of lesions and understand the condition of diseased bronchi.
Bronchial arteriography: Clinically, it is applied to the diagnosis and treatment of lung cancer through angiographic methods based on the feature of continuous local vascular renewal and the influence of tumor on the blood vessels belonging to it, such as obstruction and stenosis.
X-ray transverse tomography (CT) with electronic computer processing: It can accurately depict the scope of intrapulmonary lesions and mediastinal metastasis, and can obtain the exact clinical stage. It can detect tumors that lack sufficient contrast or are concealed at the lung margins, subpleural, paraspinal, mediastinal and posterior to the heart. CT-localized percutaneous aspiration biopsy can accurately reach the lesion for pathological diagnosis. The ability to distinguish substantial tumors from peripheral fibroids helps to determine whether a lung cancer recurrence is present. Can detect small amount of pleural fluid. It can distinguish the tissue type of lung cancer: squamous carcinoma is a uniform mass shadow; adenocarcinoma is an uneven mass shadow.
Magnetic resonance imaging (MRI): The scope of application in chest examination is similar to that of CT. In showing the relationship between tumor and chest wall tissues, such as: apical lung cancer involving ribs, thoracic vertebrae, cervical root tissues and wrapping the subclavian artery, MRI images are better than CT, but in showing the relationship between tissue structures in the mediastinum, CT images are better than MRI.
Positron computed tomography (PET): It is beneficial to the clinical staging of lung cancer patients and the follow-up of postoperative patients. However, it has not been widely used in clinical practice because of the high cost of the examination.
Sputum cytology examination: a simple, non-invasive and effective diagnostic method. The more times the test is sent, the higher the positive rate is, and the detection rate is about 50-80%. Before taking sputum specimens, patients should clean their mouths and then cough up fresh sputum from the deep part of the lungs for examination, and take the material for smear and fixed staining within 1~2 hours, and the smear should preferably choose sputum with mucus components or blood. The detection of early lung cancer is sometimes earlier than X-ray or fiberoptic bronchoscopy. Universal screening can detect “negative lung cancer”.
Fiberoptic bronchoscopy: This test is easy and safe to perform, less painful for patients and easy to accept, so it has become one of the most important routine tests for lung cancer diagnosis. It is especially important for the diagnosis of central lung cancer. It can observe the specific location of lesions, the extent of involvement, and take biopsy or film of lesions to make clear pathological or cytological diagnosis; for patients who repeatedly have blood in sputum for unknown reasons or cancer cells found in sputum (occult lung cancer) without obvious abnormalities in chest X-ray, fiberoptic bronchoscopy is of great importance. Fiberoptic bronchoscopy is also used to do local bronchial lavage of peripheral lung lesions, and to collect the lavage fluid and centrifuge it for cytological smear examination.
Other
Transdermal lung aspiration: For patients with suspected lung cancer, especially peripheral lung cancer, transdermal lung aspiration is feasible if the diagnosis is not clear by sputum cytology and fiberoptic bronchoscopy. It should generally be performed under X-ray fluoroscopic localization or CT localization. Some complications may occur with this test, the common ones are pneumothorax, hemoptysis, hemothorax, fever, etc. The current preference is to use fine needle aspiration for smear cytology to reduce complications and needle tract cancer cell implantation. It is one of the invasive examination methods.
Biopsy (biopsy): Many cases with complicated conditions can be clearly diagnosed by one biopsy. There are many biopsy methods, including lymph node biopsy, thoracentesis, mediastinoscopic biopsy, dissecting chest biopsy and subcutaneous nodule and soft tissue biopsy, etc.
Tumor marker examination: the methods used so far are often not specific enough, but the use of comprehensive early diagnosis including immunodiagnosis can greatly improve the diagnosis rate of lung cancer. Tumor markers currently available for diagnosis include carcinoembryonic antigen (CEA), squamous cell associated antigen (SCC), CA125, etc.
Diagnostic criteria
The diagnosis of lung cancer is based on clinical manifestations, physical signs, imaging examination, cytological examination, pathological examination and serological examination, among which the results of cytological and pathological examination are the gold standard for the final diagnosis of lung cancer.
Staging and staging
Staging
UICC TNM staging of lung cancer (2007)
T-stage.
TX: No primary tumor is found, or cancer cells are found by sputum cytology or bronchial lavage but cannot be detected by imaging and bronchoscopy.
T0: No evidence of primary tumor.
Tis: carcinoma in situ.
T1: Tumor with maximum diameter ≤ 3 cm, surrounded by lung tissue and dirty pleura. Bronchoscopy showed that the tumor invaded the lobar bronchus and did not invade the main bronchus.
T1a: tumor maximum diameter ≤2cm.
T1b: tumor maximum diameter >2cm, ≤3cm.
T2: tumor with maximum diameter >3cm, ≤7cm; invasion of main bronchus, but beyond 2cm from the bulge; invasion of dirty pleura; obstructive pneumonia or partial pulmonary atelectasis, excluding total pulmonary atelectasis. T2 is classified as T2 if any of the above conditions are met.
T2a: Tumor maximum diameter >3cm, ≤5cm.
T2b: tumor maximum diameter >5cm, ≤7cm.
T3: tumor maximum diameter >7cm; direct invasion of any of the following organs, including: chest wall (including suprapulmonary sulcus tumor), diaphragm, phrenic nerve, mediastinal pleura, pericardium; talar ridge.