What Are the Different Types of Lung Cancer?

Lung cancer is one of the fastest growing morbidity and mortality rates and one of the most threatening to the health and life of the population. In the past 50 years, many countries have reported a significant increase in the incidence and mortality of lung cancer. The incidence and mortality of lung cancer in men account for the first place in all malignancies, and the incidence rate for women is the second, and the mortality rate is the second. The cause of lung cancer is not completely clear so far. A large amount of data shows that long-term heavy smoking is closely related to the occurrence of lung cancer. Existing studies have proven that long-term smokers have a lung cancer risk of 10 to 20 times that of non-smokers. The younger they start smoking, the higher the chance of lung cancer. In addition, smoking not only directly affects my physical health, but also adversely affects the health of the surrounding population, leading to a significant increase in the prevalence of lung cancer in passive smokers. The incidence of lung cancer in urban residents is higher than that in rural areas, which may be related to urban air pollution and carcinogens in smoke and dust. Therefore, non-smoking should be promoted and urban environmental sanitation work should be strengthened.

Basic Information

nickname
Bronchial lung cancer
English name
lung cancer
Visiting department
Oncology, Thoracic Surgery
Multiple groups
Smokers, people with chronic lung diseases, people exposed to gas and asphalt, people who receive excessive radiation
Common causes
Smoking, occupational exposure, environmental pollution, tuberculosis, chronic inflammation of the lungs, family history, etc.
Common symptoms
Cough, expectoration, blood in sputum, low fever, chest pain, stagnation, etc.

Causes of lung cancer

Smoking
Smoking is currently considered to be the most important high-risk factor for lung cancer. There are more than 3,000 chemicals in tobacco, among which multi-chain aromatic hydrocarbon compounds (such as benzopyrene) and nitrosamines have strong carcinogenic activity. Multi-chain aromatic hydrocarbons and nitrosamines can cause DNA damage in bronchial epithelial cells through various mechanisms, causing activation of oncogenes (such as Ras gene) and inactivation of tumor suppressor genes (such as p53, FHIT gene, etc.), and then cause Transformation, eventually cancerous.
2. Occupational and environmental exposure
Lung cancer is the most important type of occupational cancer. It is estimated that about 10% of lung cancer patients have a history of environmental and occupational exposure. The following nine occupational environmental carcinogens have been shown to increase the incidence of lung cancer: by-products of aluminum products, arsenic, asbestos, bis-chloromethylether, chromium compounds, coke ovens, mustard gas, nickel-containing impurities, vinyl chloride. Long-term exposure to beryllium, cadmium, silicon, formalin and other substances will also increase the incidence of lung cancer. Air pollution, especially industrial exhaust gases, can cause lung cancer.
3. Ionizing radiation
The lungs are organs that are sensitive to radiation. The first evidence of ionizing radiation-induced lung cancer came from data from the Schneeberg-joakimov mine. The concentration of radon and its progeny in the air in the mine was mostly small cell carcinoma of the bronchi. In the United States, 70% to 80% of miners who have mined radioactive ore have died of occupational lung cancer caused by radiation, mainly squamous cell carcinoma. The time from onset to onset is 10 to 45 years, the average time is 25 years, and the average age of onset Is 38 years old. Incidence of radon and its progeny began to increase when the cumulative accumulation exceeded 120 working level days (WLM), and it increased more than 20 to 30 times more than 1800 WLM. Exposure of mice to gases and dust from these mines can induce lung tumors. There has been a significant increase in lung cancer among Japanese atomic bomb survivors. During a life-long follow-up of survivors of the Hiroshima Atomic Bomb, Beebe found that survivors less than 1400m from the explosion center had significantly more deaths from lung cancer than survivors from 1400 to 1900m and 2000m away from the explosion center.
4. Previous chronic lung infections
Such as patients with tuberculosis, bronchiectasis, etc., bronchial epithelium may metamorphose into squamous epithelium during chronic infection, causing cancer, but it is rare.
5. Genetic factors
Familial aggregation, genetic susceptibility, and decreased immune function. Metabolic and endocrine dysfunction may also be affected.
Lung cancer plays an important role. Many studies have demonstrated that genetic factors may play an important role in people and / or individuals who are susceptible to environmental carcinogens.
6. Air pollution
The incidence of lung cancer in developed countries is high, mainly due to the pollution of the atmosphere caused by hazardous substances such as benzopyrene carcinogenic hydrocarbons generated from asphalt road dust after combustion in industries and developed regions, petroleum, coal, and internal combustion engines. Air pollution and smoking may contribute to the incidence of lung cancer in synergy.

Spread of lung cancer

Direct diffusion
Tumors near the periphery of the lungs can invade the visceral pleura, and cancer cells fall off into the pleural cavity and form an implanted metastasis. Central or near mediastinal tumors can invade the visceral pleura, chest wall tissue, and mediastinal organs.
2. Hematogenous metastasis
After the cancer cells return to the left heart with the pulmonary veins, they can metastasize to any part of the body. Common metastases are liver, brain, lung, skeletal system, adrenal gland, pancreas and other organs.
3. Lymphatic metastasis
Lymphatic metastasis is the most common metastatic pathway for lung cancer. Cancer cells pass through the bronchial tubes and lymph vessels around the pulmonary blood vessels, invade the adjacent lung segments or lobular lymph nodes around the bronchi, then reach the hilar or subcarinal lymph nodes, then penetrate the mediastinal and paratracheal lymph nodes, and finally involve the supraclavicular or neck lymph nodes .

Clinical manifestations of lung cancer

The clinical manifestations of lung cancer are more complicated. The presence, severity, and appearance of symptoms and signs depend on the location of the tumor, the type of pathology, the presence or absence of metastases and complications, and the patient's response and tolerance. The early symptoms of lung cancer are usually mild, without any discomfort. Symptoms of central lung cancer appear early and severe, and symptoms of peripheral lung cancer appear late and mild, or even asymptomatic. They are often found during physical examination. The symptoms of lung cancer are broadly divided into local symptoms, systemic symptoms, extrapulmonary symptoms, infiltration and metastatic symptoms.
(A) local symptoms
Local symptoms are those caused by the tumor itself irritating, blocking, infiltrating, and compressing the tissue when it grows locally.
Cough
Cough is the most common symptom, with cough as the first symptom, accounting for 35% to 75%. Cough caused by lung cancer may be related to changes in bronchial mucus secretion, obstructive pneumonia, pleural invasion, atelectasis, and other intrathoracic complications. When the tumor grows in the bronchial mucosa with a large diameter and an external stimulus, it can produce a cough similar to foreign body-like stimuli. The typical manifestation is paroxysmal dry cough, which is often difficult to control. When the tumor grows in the smaller bronchial mucosa below the segment, the cough is mostly not obvious, or even no cough. For patients who smoke or suffer from chronic bronchitis, such as exacerbation of cough, frequency change, frequency of cough changes, such as high-pitched metal sounds, especially in the elderly, we must be highly vigilant about the possibility of lung cancer.
2. Blood or hemoptysis in sputum
Blood in the sputum or hemoptysis is also a common symptom of lung cancer, accounting for about 30% of the first symptoms. Due to the abundant blood supply and fragile texture of tumor tissue, blood vessels may rupture and cause bleeding during severe cough, and hemoptysis may also be caused by tumor local necrosis or vasculitis. Lung cancer cough is characterized by intermittent or persistent, repeated small amounts of blood in the sputum, or a small amount of hemoptysis. Occasionally, large blood vessels are broken, large cavities are formed, or tumors break into the bronchial and pulmonary blood vessels. Hemoptysis.
3. Chest pain
About 25% of the first symptoms are chest pain. Often manifested as irregular or dull pain in the chest. In most cases, peripheral lung cancer invades the parietal pleura or chest wall, and can cause sharp and intermittent pleural pain. If it continues to develop, it develops into constant drilling pain. Difficult to locate mild chest discomfort is sometimes associated with central lung cancer invading the mediastinum or involving blood vessels and peripheral bronchial nerves, and 25% of patients with malignant pleural effusion complain of dull chest pain. Persistent sharp and severe chest pain that is not easily controlled by drugs often indicates that there has been extensive pleural or chest wall invasion. Persistent pain in the shoulder or chest and back indicates the possibility of tumor invasion near the mediastinum of the lung lobe.
4. Chest tightness and shortness of breath
About 10% of patients have this symptom as the first symptom, which is more common in central lung cancer, especially patients with poor lung function. The main causes of dyspnea include: advanced lung cancer, extensive metastatic mediastinal lymph nodes, shortness of breath, and even suffocation may occur when the trachea, carina or main bronchi are compressed. When a large amount of pleural effusion compresses the lung tissue and severely displaces the mediastinum, or when there is pericardial effusion, chest tightness, shortness of breath, and dyspnea may occur, but the symptoms can be relieved after the fluid is drawn. Diffuse bronchioloalveolar carcinoma and bronchial disseminated adenocarcinoma reduce the breathing area and gas diffusion dysfunction, which leads to severe imbalance of ventilation / blood flow ratio, which causes dyspnea to gradually increase, often accompanied by cyanosis. Others: including obstructive pneumonia. Atelectasis, lymphangiogenic lung cancer, tumor microembolism, upper airway obstruction, spontaneous pneumothorax, and chronic lung diseases such as COPD.
5. hoarse
Hoarseness is the first complaint in 5% to 18% of lung cancer patients, usually accompanied by cough. Hoarseness usually indicates a direct mediastinal invasion or lymph node growth involving the ipsilateral recurrent laryngeal nerve and paralysis of the left vocal cord. Vocal cord paralysis can also cause upper airway obstruction to varying degrees.
(Two) systemic symptoms
Fever
The first symptom is 20% to 30%. There are two causes of fever caused by lung cancer. One is inflammatory fever. When central lung cancer tumors grow, they often block the opening of the segment or bronchus, which causes fever due to obstructive pneumonia or atelectasis in the corresponding lung lobe or segment. At about 38 ° C, rarely exceeding 39 ° C, antibiotic treatment may work, and shadows may be absorbed, but due to poor drainage of secretions, often recurrent, about 1/3 of patients can repeatedly develop pneumonia at the same site within a short period of time. Peripheral lung cancer often develops fever when tumors compress adjacent lung tissue and cause inflammation. The second is cancerous fever, which is mostly caused by tumor necrosis tissue being absorbed by the body. Such fever and anti-inflammatory drugs are not effective. Hormones or indole drugs have a certain effect.
2. Wasting and cachexia
In the late stage of lung cancer, loss of appetite due to infection and pain, increased consumption of tumor growth and toxins, and increased levels of cytokines such as TNF and Leptin in the body can cause severe wasting, anemia, and cachexia.
(Three) extrapulmonary symptoms
Due to certain special active substances (including hormones, antigens, enzymes, etc.) produced by lung cancer, patients may have one or more extrapulmonary symptoms, which often appear before other symptoms, and may fade or appear as the tumor grows and falls. , Clinically, pulmonary bone and joint hyperplasia is more common.
1. Pulmonary osteoarthrosis
The main clinical manifestations are sacral fingers (toes), periosteal hyperplasia of distal long bones, new bone formation, swelling, pain and tenderness of affected joints. The long bones are the tibia, humerus and metacarpal, and the joints are large joints such as the knee, ankle, and wrist. The incidence of cricket fingers and toes is about 29%, which is mainly seen in squamous cell carcinoma; the incidence of proliferative osteoarthropathy is 1% to 10%, which is mainly seen in adenocarcinoma, which is rarely seen in small cell carcinoma. The exact etiology is not completely clear, and may be related to estrogen, growth hormone or nerve function. It can be relieved or subsided after surgical removal of cancer, and it can occur again when it recurs.
2. Tumor-related ectopic hormone secretion syndrome
These symptoms occur in about 10% of patients and can occur as first symptoms. Other patients are asymptomatic, but one or more plasma ectopic hormones can be detected. Such symptoms are more common in small cell lung cancer.
(1) Ectopic adrenocorticotropic hormone (ACTH) secretion syndrome Because tumors secrete ACTH or adrenocorticotropic hormone-releasing factor active substances, plasma cortisol increases. The clinical symptoms are roughly similar to Cushing's syndrome, and may include progressive muscle weakness, peripheral edema, hypertension, diabetes, and hypokalemic alkalosis. It is characterized by a rapid progression of the disease course, and severe mental disorders, accompanied by The skin is hyperpigmented, while concentric obesity, bloodiness, and purple markings are not obvious. The syndrome is more common in lung adenocarcinoma and small cell lung cancer.
(2) Ectopic gonadotropin secretion syndrome is caused by the tumor's autonomous secretion of LH and HCG and stimulates the secretion of gonadal steroids. Mostly manifested as male bilateral or unilateral mammary gland development, which can occur in various cell types of lung cancer. Undifferentiated and small cell cancers are common. Occasionally, abnormal penile erections are seen. In addition to the abnormal secretion of hormones, it may also be caused by penile vascular embolism.
(3) Ectopic parathyroid hormone secretion syndrome is caused by tumors secreting parathyroid hormone or an osteolytic substance (polypeptide). Clinically, it is characterized by high blood calcium and low blood phosphorus. Symptoms include loss of appetite, nausea, vomiting, abdominal pain, thirst, weight loss, tachycardia, arrhythmia, restlessness, and mental disorders. More common in squamous cell carcinoma.
(4) Ectopic insulin secretion syndrome The clinical manifestations are subacute hypoglycemia symptoms, such as insanity, hallucinations, and headaches. The reason may be related to the tumor's large consumption of glucose, secretion of humoral substances similar to insulin activity, or secretion of insulin-releasing peptides.
(5) Carcinoid syndrome is caused by tumors secreting serotonin. Manifestations include bronchospasm asthma, skin flushing, paroxysmal tachycardia, and watery diarrhea. More common in adenocarcinoma and oat cell carcinoma.
(6) Neuro-muscular syndrome (Eaton-Lambert syndrome) is caused by tumors secreting arrowhead-like substances. Appears as voluntary muscle loss and extreme fatigue. More common in small cell undifferentiated cancer. Others include peripheral neuropathy, spinal root ganglion cells and neurodegeneration, subacute cerebellar degeneration, cortical degeneration, polymyositis, etc., and may have pain and weakness in limbs, dizziness, nystagmus, ataxia, difficulty walking dementia.
(7) Ectopic growth hormone syndrome manifested as hypertrophic osteoarthritis is more common in adenocarcinoma and undifferentiated cancer.
(8) Syndrome of abnormal antidiuretic hormone secretion is caused by cancer cells secreting a large amount of ADH or peptide substances with antidiuretic effect. Its main clinical features are hyponatremia, accompanied by low osmotic pressure of serum and extracellular fluid (<270 mOsm / L), continuous renal rejection, urinary osmotic pressure greater than plasma osmotic pressure (urine specific gravity> 1.200), and water poisoning. More common in small cell lung cancer.
3. Other performance
(1) Skin lesions Acanthosis nigricans and dermatitis are more common in adenocarcinoma. Skin pigmentation is caused by tumors secreting melanocyte stimulating hormone (MSH), which is more common in small cell carcinomas. Others still have scleroderma, palmar plantar hyperkeratosis and so on.
(2) Cardiovascular system All types of lung cancers can have abnormal coagulation mechanisms, and may have ambulatory venous embolism, phlebitis, and nonbacterial embolizing endocarditis, which can occur months before the diagnosis of lung cancer.
(3) Hematology system There may be chronic anemia, purpura, erythrocytosis, and leukemia-like reactions. It may be caused by decreased iron absorption, shortened life span of erythropoiesis, and capillary hemorrhagic anemia. In addition, DIC can occur in various cell types of lung cancer, which may be related to tumor release of procoagulant factors. Patients with lung squamous cell carcinoma may be associated with purpura.
(IV) Symptoms of invasion and metastasis
Lymph node metastasis
The most common are mediastinal and supraclavicular lymph nodes, most of which are on the same side of the lesion, and a few can be on the contralateral side. Most are hard, single or multiple nodules, and can sometimes be seen for the first complaint. Swollen lymph nodes next to the trachea or under the bulge can compress the airway and cause chest tightness. Shortness of breath or even suffocation. Compression of the esophagus may cause difficulty swallowing.
2. Pleural invasion and / or metastasis
Pleura is a common site of invasion and metastasis of lung cancer, including direct invasion and implanted metastasis. The clinical manifestations vary depending on the presence or absence of pleural effusion and pleural effusion. In addition to direct invasion and metastasis, the causes of pleural effusion also include obstruction of lymph nodes, and associated obstructive pneumonia and atelectasis. Common symptoms include dyspnea, cough, chest tightness, and chest pain, etc., and there can be no symptoms at all; physical examination shows intercostal fullness, intercostal widening, reduced respiratory sounds, reduced speech tremor, percussion sounds, mediastinal displacement, etc. , Pleural fluid can be serous, serous or bloody, most of which are exudates. Malignant pleural fluid is characterized by a rapid growth rate and mostly bloody. Spontaneous pneumothorax can occur in extremely rare lung cancers. The mechanism is direct invasion of the pleura and obstructive emphysema rupture. It is more common in squamous cell carcinoma and has a poor prognosis.
3. Superior Vena Cava Syndrome (SVCS)
The tumor directly invades or mediastinal lymph node metastasis compresses the superior vena cava, or the embolism in the cavity makes it narrow or occluded, causing blood flow disorders, and a series of symptoms and signs such as headache, facial edema, cervical and thoracic varices, increased pressure , Dyspnea, cough, chest pain and difficulty swallowing, and often have syncope or dizziness when bending over. The anterior chest and epigastric veins can be compensated for varicose veins, reflecting the time of the superior vena cava obstruction and the anatomic location of the obstruction. The symptoms and signs of superior vena cava obstruction are related to its location. If the innominate vein on one side is obstructed, the blood flow on the head, face, and neck can flow back to the heart through the opposite innominate vein, and the clinical symptoms are mild. If the superior vena cava obstruction occurs below the entrance of the odd vein, in addition to the dilation of the veins above, there will still be abdominal vein bloating, and blood will flow into the inferior vena cava in this way. If the obstruction develops rapidly, brain edema may occur with headache, lethargy, irritability, and changes in consciousness.
4. Kidney metastasis
Renal metastases are found in about 35% of patients who die from lung cancer, and are also the most common site of metastasis in patients who die within 1 month after lung cancer surgery. Most renal metastases are asymptomatic and can sometimes manifest as low back pain and renal insufficiency.
5. Digestive tract metastasis
Liver metastasis can be manifested as decreased appetite, pain in the liver area, and sometimes accompanied by nausea. Serum -GT is often positive, and AKP is progressively increased. On examination, hepatomegaly, stiff, and nodular can be found. Small cell lung cancer is prone to metastases to the pancreas, and pancreatic inflammation or obstructive jaundice can occur. Lung cancer of various cell types can metastasize to the liver, gastrointestinal tract, adrenal glands, and retroperitoneal lymph nodes. It is clinically asymptomatic and is often found during physical examination.
6. Bone metastasis
The most common sites of bone metastases in lung cancer are ribs, vertebrae, sacrum, and femur. However, ipsilateral ribs and vertebrae are more common, manifested as localized pain with site-specific tenderness and palatalgia. Spinal metastases can compress the spinal canal and cause symptoms of obstruction or compression. Joint involvement can cause joint cavity fluid, puncture may detect cancer cells.
7. Central nervous system symptoms
(1) The incidence of brain, meningeal, and spinal cord metastases is about 10%, and the symptoms may vary depending on the site of metastasis. Common symptoms are increased intracranial pressure, such as headache, nausea, vomiting, and changes in mental state. Rare symptoms include seizures, neurological involvement, hemiplegia, ataxia, aphasia, and sudden syncope. Meningeal metastases are less common than brain metastases and often occur in patients with small cell lung cancer, with symptoms similar to brain metastases.
(2) Encephalopathy and cerebellar degeneration Encephalopathy is mainly manifested as dementia, psychosis and organic lesions. Cerebellar degeneration is manifested as acute or subacute limb dysfunction, difficulty in movement of limbs, tremor of movement, difficulty in pronunciation, dizziness, etc. It has been reported that the above symptoms can be relieved after tumor resection.
8. Heart Invasion and Metastasis
It is not uncommon for lung cancer to affect the heart, especially in central lung cancer. Tumors can invade the heart directly, or they can spread retrogradely in the lymphatic vessels, blocking the draining lymphatics of the heart and causing pericardial effusion. Those with slower development can be asymptomatic, or have only pain in the precardiac area, subcostal arch, or upper abdomen. Those with rapid development may present typical symptoms of pericardial tamponade, such as anxiety, palpitations, jugular facial vein anger, enlarged heart circles, low heart sounds, hepatomegaly, and ascites.
9. Peripheral nervous system symptoms
Horner's syndrome is caused by cancerous tumor compression or invasion of the cervical sympathetic nerve, which is characterized by narrowing of the pupil on the affected side, drooping of the eyelid, invagination of the eyeball, and no sweat on the face. Compression or invasion of the brachial plexus nerve causes the brachial plexus nerve compression sign, which is manifested by ipsilateral upper limb burning-like radiation pain, local paresthesia, and trophic atrophy. When the tumor invades the phrenic nerve, it can be in favor of palsy paralysis, chest tightness, shortness of breath, and contradictory motion of the phrenic muscle can be seen under X-ray perspective. Compression or violation of the recurrent laryngeal nerve can cause vocal cord paralysis and hoarseness. Apical tumor of the lung (superior sulcus tumor) invades neck 8 and chest 1 nerves, brachial plexus nerves, sympathetic ganglia and adjacent ribs, causing severe shoulder and arm pain, paresthesia, paresis or weakness in one arm, muscle atrophy The so-called Pancoast syndrome.

Lung cancer examination

1. X-ray inspection
X-ray examination can understand the location and size of lung cancer. You may see local emphysema caused by bronchial obstruction, atelectasis or invasive lesions near the lesion or pulmonary inflammation.
2. Bronchoscopy
Bronchoscopy can directly observe the lesions of the bronchial intima and lumen. Tumor tissue can be taken for pathological examination, or bronchial secretions for cytological examination, in order to confirm the diagnosis and determine the type of histology.
3. Cytological examination
Sputum cytology is a simple and effective method for general screening and diagnosis of lung cancer. Most patients with primary lung cancer can find shed cancer cells in sputum. The positive rate of sputum cytology of central lung cancer can reach 70% to 90%, and the positive rate of sputum test of peripheral lung cancer is only about 50%.
4. Thoracotomy
After a variety of examinations and short-term diagnostic treatment of lung masses have not been able to determine the nature of the lesion, and the possibility of lung cancer cannot be ruled out, a thoracotomy should be performed. This can avoid delaying the disease and losing the opportunity for early treatment of lung cancer patients.
5.ECT inspection
ECT bone imaging can detect bone metastases earlier. X-ray films and bone imaging have positive findings. If the osteogenic reaction in the lesion area is calm and the metabolism is not active, the bone imaging is negative, and the X-ray film is positive. The two are complementary, which can improve the diagnosis rate. It should be noted that the false positive rate of ECT bone imaging in the diagnosis of bone metastases in lung cancer can reach 20% to 30%. Therefore, patients with positive ECT bone imaging need to have MRI scans of bones in positive areas.
6. Mediastinoscopy
Mediastinoscopy is mainly used for patients with mediastinal lymph node metastasis, which is not suitable for surgical treatment, and other methods cannot obtain pathological diagnosis. Mediastinoscopy is performed under general anesthesia. Make a transverse incision in the upper part of the sternum, bluntly separate the anterior cervical soft tissue to the anterior tracheal space, bluntly release the anterior tracheal channel, place it in the observation mirror and slowly pass behind the innominate artery, observe the trachea, tracheobronchial angle, and subkeel The enlarged lymph nodes at the site were dissected with special biopsy forceps to obtain lymph node tissue for pathological examination.
The diagnosis of primary bronchial lung cancer includes symptoms, signs, imaging findings, and examination of sputum cancer cells.

Lung cancer diagnosis

Make a diagnosis based on clinical symptoms, signs, imaging, and histopathology. Early diagnosis of lung cancer is of great significance. Only when it is diagnosed and treated early in the disease can a better effect be obtained.
Lung cancer lacks typical symptoms in the early stage. For people over 40 years of age, regular chest X-ray screening should be performed. Patients with primary or metastatic symptoms of lung cancer should undergo chest X-ray examination or chest CT examination in time. When a lung mass is found, the diagnosis of lung cancer should be taken into consideration first, and further examination should be performed, and the diagnosis should be confirmed by histopathological examination.

Differential diagnosis of lung cancer

Typical lung cancer is easy to identify, but in some cases, lung cancer is easily confused with:
Tuberculosis
Tuberculosis, especially tuberculoma (bulb), should be distinguished from peripheral lung cancer. Pulmonary tuberculoma (ball) is more common in young patients, has a longer course, is less likely to have bloody sputum, and tuberculosis bacteria are found in the sputum. It is mostly circular in imaging, and it is found in the tip or posterior segment of the upper leaf. The volume is small, no more than 5cm in diameter, the border is smooth, and the density is uneven. There are often scattered tuberculosis lesions around the tuberculoma (ball) called satellite foci. Peripheral lung cancer is more common in patients over 40 years of age, and sputum with blood is more common. Positive cancer cells in sputum reach 40% to 50%. X-ray chest radiographs are often lobular, with irregular edges, small burrs, and pleural shrinkage, and they grow faster. In some cases of chronic tuberculosis, lung cancer can occur on the basis of tuberculosis, and further sputum cytology and bronchoscopy must be performed, and a thoracotomy should be performed if necessary.
2. Lung infection
Lung infections are sometimes difficult to distinguish from obstructive pneumonia caused by lung cancer obstructing the bronchi. However, if pneumonia occurs in the same place multiple times, you should be more vigilant, you should be highly suspected to be caused by tumor blockage, and you should take the patient's sputum for cytology and fiberoptic airway examination. When the remaining inflammation is absorbed by the fibrous tissue to form a nodule or an inflammatory pseudotumor, it is difficult to distinguish it from peripheral lung cancer. A suspensory thoracotomy should be performed for suspicious cases.
3. benign tumors of the lungs
Benign tumors of the lung: structural tumors, chondroma, fibroma, etc. are rare, but they must be distinguished from peripheral lung cancer. Benign tumors have a long course and are mostly clinically asymptomatic. X-ray films are often round Block shadows, neat edges, no burrs, and no leaves. Bronchial adenoma is a low-grade malignant tumor that often occurs in young women. Therefore, clinical symptoms such as pulmonary infection and hemoptysis often occur. Fibrobronchoscopy can often make a diagnosis.
4. Mediastinal lymphoma (lymphosarcoma and Hodgkin's disease)
Clinically, there are often cough, fever and other symptoms. Imaging shows that the mediastinum is widened and lobulated, which is sometimes difficult to distinguish from central lung cancer. If the lymph nodes in the supraclavicular or axillary are enlarged, a biopsy should be performed to confirm the diagnosis. Lymphosarcoma is particularly sensitive to radiation therapy. For suspicious cases, low-dose radiation therapy can be tried, which can significantly reduce the mass. This experimental treatment is helpful for the diagnosis of lymphosarcoma.

Lung Cancer Treatment

(1) Chemotherapy
Chemotherapy is the main treatment method for lung cancer. More than 90% of lung cancer needs chemotherapy. The efficacy of chemotherapy for small cell lung cancer is relatively positive in both early and advanced stages, and even about 1% of early small cell lung cancer is cured by chemotherapy. Chemotherapy is also the main method for the treatment of non-small cell lung cancer. The tumor response rate of chemotherapy for non-small cell lung cancer is 40% -50%. Chemotherapy generally does not cure non-small cell lung cancer, it can only prolong patient survival and improve quality of life. Chemotherapy is divided into therapeutic chemotherapy and adjuvant chemotherapy. Chemotherapy needs to choose different chemotherapy drugs and different chemotherapy schemes according to the different types of lung cancer histology. In addition to killing tumor cells, chemotherapy also damages normal human cells. Therefore, chemotherapy needs to be performed under the guidance of oncologists. In recent years, the role of chemotherapy in lung cancer has been no longer limited to patients with inoperable advanced lung cancer, but is often included as a comprehensive treatment plan for lung cancer as a systemic treatment. Chemotherapy can inhibit the bone marrow hematopoietic system, mainly the decrease of white blood cells and platelets, and can be treated with granulocyte colony-stimulating factor and platelet-stimulating factor. Chemotherapy is divided into therapeutic chemotherapy and adjuvant chemotherapy.
(Two) radiation therapy
Treatment principle
Radiotherapy has the best effect on small cell lung cancer, followed by squamous cell carcinoma and adenocarcinoma. The radiation field of lung cancer should include the primary focus and the mediastinal area with lymph node metastasis. At the same time should be supplemented by medication. Squamous cell carcinoma has moderate sensitivity to radiation. The lesions are mainly local invasion and the metastasis is relatively slow. Therefore, radical treatment is often used. Adenocarcinoma has poor sensitivity to radiation and is prone to bloodstream metastasis, so radiation therapy is rarely used. Radiotherapy is a topical treatment that often requires combined chemotherapy. The combination of radiotherapy and chemotherapy can depend on the situation of the patient, and adopt concurrent radiotherapy or alternating radiotherapy.
2. Classification of radiotherapy
According to the purpose of treatment, it is divided into radical treatment, palliative treatment, preoperative neoadjuvant radiotherapy, postoperative auxiliary radiotherapy and intracavitary radiotherapy.
3. Complications of Radiotherapy
Complications of radiotherapy for lung cancer include: radiation pneumonia, radiation esophagitis, radiation pulmonary fibrosis, and radiation myelitis. There is a positive correlation between the above-mentioned radiation-related complications and radiation dose, and there are also individual differences.
(Three) surgical treatment of lung cancer
Surgical treatment is the first and most important treatment for lung cancer, and it is also the only treatment that can cure lung cancer. The goals of surgical treatment of lung cancer are:
Complete resection of primary lesions and metastatic lymph nodes of lung cancer to achieve clinical cure;
Removal of most of the tumor, creating favorable conditions for other treatments, that is, tumor reduction surgery;
Subtractive surgery: suitable for a small number of patients, such as refractory pleural cavity and pericardial effusion, by removing the pleura and pericardial nodules, removing part of the pericardium and pleura, curing or alleviating the clinical symptoms caused by pericardial and pleural effusion Life or improving quality of life. Subtraction surgery requires both local and systemic chemotherapy. Surgical treatment often requires adjuvant chemotherapy and radiotherapy before or after surgery to improve the cure rate and survival rate of patients. The five-year survival rate for surgical treatment of lung cancer is 30% to 44%; the mortality rate for surgical treatment is 1% to 2%.
Surgical indication
Surgical treatment of lung cancer is mainly suitable for early to middle stage (stage ~ ) lung cancer, stage a lung cancer and partially selective stage b lung cancer whose tumor is confined to one chest cavity.
(1) Stage and lung cancer;
(2) Stage IIIa non-small cell lung cancer;
(3) The lesion is confined to one side of the thorax, and part of stage IIIb non-small cell lung cancer can be completely removed;
(4) Patients with stage a and some stage b lung cancer who have been downgraded after neoadjuvant chemotherapy before surgery;
(5) Non-small cell lung cancer with solitary metastasis (ie, intracranial, adrenal or liver), if the primary tumor and metastatic tumor are suitable for surgical treatment without surgical contraindications, and can reach the primary tumor and Complete removal of metastases;
(6) Non-small cell stage b lung cancer with clear diagnosis, tumor invasion of pericardium, large blood vessels, diaphragm, tracheal elongation, distant or / and micrometastases were excluded by various examinations, localized lesions, and patients had no contraindications to physiological surgery , Who can achieve complete resection of the tumor and the affected tissues and organs;
2. Contraindications for surgery
(1) Stage IV lung cancer with extensive metastasis
(2) Patients with multiple mediastinal lymph node metastases, especially those with aggressive mediastinal lymph node metastases;
(3) Stage IIIb lung cancer with contralateral hilar or mediastinal lymph node metastasis;
(4) Patients with severe visceral insufficiency who cannot tolerate surgery;
(5) Those who have bleeding disorders and cannot be corrected.
3. Choice of surgical methods for lung cancer
The principle of surgical resection is: complete removal of the primary foci and lymph nodes that may metastasize in the thorax, and preserve normal lung tissues as much as possible. Pneumonectomy should be performed with caution.
(1) Lung wedge and local resection refers to resection of wedge cancer and partial resection of lung segments. It is mainly suitable for early-stage lung cancer with small volume, old age and frailty, poor lung function or low cancer differentiation.
(2) Pneumonectomy is a dissection of the dissected lung segment. It is mainly suitable for elderly patients with peripheral solitary early lung cancer with poor cardiopulmonary function, or partial central lung cancer with local lesions located at the root of lung cancer;
(3) Pneumonectomy Pneumonectomy is suitable for lung cancer with peripheral and partial central lung cancer confined to one lobe. Central lung cancer must ensure that there is no cancer residue in the bronchial stump. If lung cancer involves two lobes or middle bronchi, upper or lower middle lobectomy can be performed;
(4) Bronchial sleeve-shaped lung lobectomy This procedure is mainly suitable for lung cancer with central lung cancer located in the bronchi or middle bronchus opening of the lung lobe. The benefit of this procedure is that it has reached the complete resection of lung cancer while retaining healthy lung tissue;
(5) Bronchial pulmonary artery sleeve-shaped lobectomy This procedure is mainly applicable to central lung cancer in which the lung is located in the bronchi or middle bronchus opening of the lung and the lungs invade the pulmonary artery trunk at the same time. In addition to bronchectomy and reconstruction, surgery also requires resection and reconstruction of the pulmonary artery trunk. The benefit of this procedure is that it has reached the complete resection of lung cancer while retaining healthy lung tissue;
(6) Tracheal bulge resection and reconstruction When a lung tumor exceeds the main bronchus involving the bulge or the side wall of the trachea but not more than 2 cm, it can be used for tracheal bulge resection or sleeve pneumonectomy. If one lobe is still retained, Efforts should be made to preserve the trachea by excision and reconstruction of the lung lobe.
(7) Pneumonectomy Pneumonectomy refers to one side of the lung, that is, right or left side pneumonectomy, which is mainly suitable for good cardiopulmonary function, more extensive lesions, younger age, and is not suitable for lung lobe or sleeve Lobectomy for lung cancer. The complication rate and mortality of pneumonectomy are high, and the long-term survival rate and quality of life of patients are not as good as those of lobectomy. Therefore, the surgical indications must be strictly controlled.
4. Surgical treatment of recurrent lung cancer
Recurrent lung cancer includes the recurrence of local residual cancer after surgery and a second primary lung cancer that newly occurs in the lungs. For the recurrence of residual cancer of the bronchial stump, reoperation should be striven for, and a bronchial sleeve shaping is performed to remove the residual cancer.
For the second primary lung cancer that occurs after complete resection of lung cancer, as long as the lung cancer is suitable for surgical treatment, the patient's visceral function can tolerate reoperation, and there is no surgical technical problem, you should consider reopening the chest Resection of recurrent lung cancer.
new method
In September 2019, British researchers developed a new detection technology that combines blood testing and computed tomography (CT) to detect lung cancer earlier and more accurately, helping patients to begin treatment as soon as possible.
Researchers from the University of Glasgow and other institutions launched a large-scale early diagnosis clinical trial for lung cancer. More than 12,000 volunteers participated. They were between 50 and 75 years old. From various factors, it is estimated that the risk of lung cancer within two years was relatively high. High crowd. The researchers used a combination of blood testing and CT testing techniques they developed and found that those patients with early lung cancer could be detected with high accuracy. Researchers say that one of the advantages of the new technology is that because of the combination of blood test information, the number of imaging required for CT testing is only about one-third of the normal number, which means that patients will receive less radiation. [1]

Lung cancer prevention

Lung cancer is preventable and controllable. Existing studies have shown that the incidence and mortality of lung cancer have decreased significantly in recent years after tobacco control and environmental protection in developed western countries. The prevention of lung cancer can be divided into three levels of prevention. Primary prevention is causative intervention; secondary prevention is screening and early diagnosis of lung cancer to achieve early diagnosis and early treatment of lung cancer; tertiary prevention is rehabilitation prevention.
Primary prevention:
1. Ban and control smoking
Foreign studies have shown that quitting smoking can significantly reduce the incidence of lung cancer, and the earlier the quitting smoking, the lower the incidence of lung cancer. Therefore, quitting smoking is the most effective way to prevent lung cancer.
2. Protect the environment
Existing research proves that air pollution, sedimentation index, smoke index, benzopyrene and other exposure doses have a positive correlation with the incidence of lung cancer. Protecting the environment and reducing air pollution are important measures to reduce the incidence of lung cancer.
3. Prevention of occupational factors
Many occupational carcinogens have been recognized to increase the incidence of lung cancer. Reducing exposure to occupational carcinogens can reduce the incidence of lung cancer.
4. Scientific diet
Adding vegetables and fruits to your diet can prevent lung cancer. [2-4]

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