I. Incidence of lung cancer
In recent decades, with the increase in the number of smokers and the intensification of atmospheric pollution, the incidence and death rate of lung cancer have been rising sharply worldwide, and now it has become the malignant tumor with the highest mortality rate and incidence rate in the world. The World Health Organization (WHO) reported in 2000 that 7.065 million people died of malignant tumors worldwide in 1997, accounting for 12.6% of deaths, among which lung cancer accounted for 19% of deaths from malignant tumors, ranking first among causes of death from malignant tumors. Feng Xing, Department of Thoracic Surgery, Hangzhou First People’s Hospital
China is no exception, the current mortality rate of lung cancer is the first among all malignant tumors, from 7.09/100,000 in the 70s to 17.54/100,000 in the early 90s, an increase of 111.85%; among them, the number of new cases from 2000 to 2005 ranged from 161,839 to 332,286 for men and from 119,648 to 165,622 for women; the mortality rate for men 35/100,000 to 42.5/100,000 for men and 12.5/100,000 to 16/100,000 for women. In Jiangsu Province, the mortality rate of lung cancer has increased 3.67 times in the past 20 years; the mortality rate of lung cancer accounts for the first place of various malignant tumors in 74 cities in the sample. In Shanghai, the incidence rate of lung cancer increased from 5.25/100,000 to 30.7/100,000 between 1960 and 1976, a six-fold increase. The annual number of lung cancer deaths in China is 600,000. British oncologist R. Peto predicted that if China does not control smoking and air pollution in time, by 2025, the annual lung cancer rate in China will exceed 1 million, becoming the world’s largest lung cancer country.
Causes of lung cancer
The exact cause of lung cancer is still unclear. After many years of research, the following factors are recognized to be closely related to the etiology of lung cancer.
1.Smoking
According to a lot of investigation data from various countries, the causes of lung cancer are very closely related to smoking. The increase of lung cancer incidence is related to the increase of tobacco sales. Tobacco contains many carcinogenic substances. The incidence of lung cancer is 20 times higher in smokers than in nonsmokers. Among the clinically diagnosed lung cancer cases, those who smoke more than 20 cigarettes a day for more than 30 years account for more than 80%.
2.Atmospheric pollution
The high incidence of lung cancer in industrially developed countries, higher in cities than in rural areas, and higher in factories and mines than in residential areas, is mainly due to the pollution of the atmosphere by harmful substances such as carcinogenic hydrocarbons produced by burning minerals such as oil and coal through internal combustion engines and asphalt road dust in industrial and transportation developed areas. Atmospheric pollution and smoking may promote each other and play a synergistic role in the incidence of lung cancer.
3.Occupational factors
It is now recognized that long-term exposure to radioactive substances such as uranium, radium and their derivatives, carcinogenic hydrocarbons, arsenic, chromium, nickel, copper, tin, iron, coal tar, asphalt, petroleum, mustard gas, etc., can induce lung cancer.
4.Chronic diseases of the lung
Such as tuberculosis, silicosis, pneumoconiosis, COPD, etc. can coexist with lung cancer.
5.Individual susceptibility
Such as family inheritance, lowered immune function, metabolic activity and endocrine dysfunction may also play a role in promoting the occurrence of lung cancer.
Early diagnosis of lung cancer
Although China has made great progress in the comprehensive treatment of lung cancer mainly by surgery, because of its high malignancy and rapid development, once the obvious symptoms appear clinically, most of them are already in the advanced stage, with a very high death rate and a 5-year survival rate of less than 10%, and the cases with early diagnosis still account for only 20%. Therefore, to improve the early diagnosis of lung cancer and to adopt comprehensive treatment measures, mainly surgery, in order to improve the treatment effect and restore life and health, has become an urgent problem to be solved. In daily life, we should pay attention to the following possible manifestations of early lung cancer for timely examination and treatment.
1.Cough
It is the most common early symptom of lung cancer patients, mostly irritating choking cough or dry cough, no sputum or little white foamy sputum. Generally, there is no history of chronic bronchitis in general, or the degree of cough is not parallel to the condition of chronic bronchitis, and the cough is aggravated when chronic bronchitis is improving, and the treatment effect is often very inconspicuous. After the secondary infection, the sputum properties change.
2.Hemoptysis
It is also one of the most common symptoms of lung cancer. It is characterized by sudden hemoptysis or blood in sputum in middle-aged and elderly people, or repeated “pneumonia” coughing up bloody sputum in some cases.
3.Pestle-like finger
It is characterized by hypertrophy of the first joint of the fingers and toes, with the nails protruding and becoming curved, often accompanied by pain.
Arthritis and pestle finger co-exist together. It often appears when the lung cancer lesion is very small, manifesting as burning pain in elbow, knee, wrist, ankle, and metacarpophalangeal joints, and obstruction of movement, whether it is sunny or cloudy, or even difficulty in walking. These long-term joint pain symptoms are very similar to “arthritis” and can be easily misdiagnosed.
4.Shoulder and back pain
Lung cancer erodes the pleura and involves the ribs and chest wall tissues, thus causing shoulder and back pain. It is characterized by mild soreness and swelling at the beginning, then mainly pain, and discharge-like pain when it is severe. Most of the pain occurs in the ipsilateral shoulder and arm of the cancer, and a few of them are in both arms, often accompanied by weakness or numbness of limbs, inability to lift and hold things.
5, male breast enlargement
Male breast enlargement on one side or both sides like female is often overlooked and even misdiagnosed as simple breast enlargement and removed. It is due to the ability of certain lung cancer cells to secrete chorionic gonadotropin, which causes hyperplasia of breast tissue and enlarges the breast. Its appearance is about one year earlier than pulmonary symptoms such as cough, blood in sputum, chest pain and shortness of breath.
6.Multiple circumferential myositis
It manifests as progressive peripheral weakness and loss of appetite, and when aggravated, it can be difficult to walk and difficult to get up from bed.
7.Heartiness
It often occurs suddenly, progresses rapidly, or even completely loses voice, and most patients have chest pain. Because the cancer invades and compresses the nerves that govern the vocal cords, there is no obvious effect after rest and anti-inflammatory symptomatic treatment.
8.Symptoms of neuromuscular lesion
Neuromuscular symptoms are the most common among various paraneoplastic syndromes, which can be as high as 15%. About half of the cases are small cell undifferentiated carcinoma, the cause of which is still unclear. Clinical manifestations include mental disorders, depression or dementia. Those with degenerative cerebellar degeneration present with ataxia and gait difficulties. Sensory nerve involvement presents with abnormal peripheral nerve sensation, loss of tendon reflexes and deafness. Motor nerve involvement may cause weakness of proximal limb muscles, progressive myositis and muscle atrophy. These clinical manifestations often appear at the early stage of lung cancer, sometimes one year before the definite diagnosis of lung cancer.
9.Companying cancer syndrome
Neurosecretory granules of undifferentiated small cell carcinoma and bronchial carcinoid tumor can secrete vasoactive substances such as 5-hydroxytryptamine, catecholamine, hydroxytryptophan and bradykinin, causing paroxysmal facial skin flushing or edema, enhanced intestinal motility, diarrhea, nausea, vomiting, croup, skin itching, abnormal sensation, accelerated heart rate and reduced blood pressure. A few squamous epithelial cell carcinomas may secrete ectopic parathyroid-like hormone causing hyperparathyroidism, elevated blood calcium, elevated blood phosphate, and increased urinary calcium. Clinical symptoms include weakness, fatigue, loss of appetite, nausea, vomiting, thirst, polyuria, weight loss, drowsiness and mental disturbance. Undifferentiated large cell carcinoma may secrete ectopic gonadotropins, leading to feminization of the breast in male patients, often accompanied by pulmonary hypertrophic osteoarthralgia and pestle-like fingers (toes). Squamous epithelial cell carcinoma may secrete ectopic insulin-like substances and produce hypoglycemia. Lung carcinomas that secrete ectopic pro-adrenocorticotropic hormones, often undifferentiated small cell carcinomas, can cause Cushing’s syndrome. Increased plasma adrenocorticotropic hormone and urinary 17-hydroxycorticosteroid, and excessive secretion of antidiuretic hormone can lead to increased blood sodium and decreased blood chloride, resulting in clinical symptoms such as increased body water, loss of appetite, nausea, vomiting and weakness, impaired consciousness and coma, etc. Most of these symptoms can disappear or be relieved after removal of the carcinoma.
10.Other manifestations
Such as chest pain, chest tightness, shortness of breath, fever, weakness, loss of appetite and weight loss without obvious reasons.
With the development of medicine and the application of molecular biology technology in life science, the diagnosis technology of lung cancer is also developing, which is mainly divided into impactological examination, nuclear medicine examination and pathological examination. The former includes chest X-ray, chest CT, chest MRI, etc.; nuclear medicine examination includes ECT and PET or PET/CT; pathological examination includes sputum cytology, fiberoptic bronchoscopy, percutaneous lung aspiration biopsy under CT localization, surgical (including mediastinoscopy and thoracoscopy) biopsy or pathology and relevant examination of pleural fluid. At present, there are also examinations of lung cancer markers, which are some special substances in the blood, and their appearance or elevated levels often indicate the existence of certain tumors; in the process of cell transformation from normal state to tumor, a series of changes in intracellular protein expression profiles are bound to occur, and tumor molecular markers are the molecules produced by cells in abnormal state. However, their specificity is poor and need to be analyzed and judged together with the previous examinations.
IV. Treatment of lung cancer
Surgery is still an important treatment for lung cancer, but the efficacy of surgery has entered a plateau, with 5-year overall survival rates of 70-90% for stage IA, 50-70% for stage IB, 50% for stage II, and 15% for stage IIIA. In a study of 16,000 patients in 8 clinical centers in China, the surgical resection rate was 79.7%-97.8%, the complication rate was 1.7%-15.7%, the operative mortality rate was 0.8%-3.1%, and the 5-year overall survival rate was 27.2%-40.6%. Surgical treatment alone is ineffective in further improving survival, and surgery-based combination therapy has become the main treatment modality. Following evidence-based medical evidence and developing treatment plans based on large-scale clinical trials are gradually becoming the treatment of choice in various clinical institutions. The individualized treatment model focusing on lung cancer is gradually accepted by thoracic surgeons.
According to years of development, China’s thoracic surgery has reached the following important consensus on the treatment of lung cancer.
1. Accurate preoperative TNM staging is the scientific basis for selecting the treatment mode. It can avoid overtreatment, accurately assess and improve survival rate, and is conducive to carrying out clinical research on lung cancer and evaluating the efficacy of surgery and drugs. In terms of preoperative assessment of mediastinal lymph node metastasis, it is usually considered that PET-CT is better than PET than CT, with specificity of 82-97% for PET-CT, 91% for PET and 77% for CT. Sensitivity PET-CT 83-93%, PET 79%, CT 60%. Accuracy of PET-CT is 86-94%.
2. Standardize the surgical mode of lung cancer staging, and minimize or eliminate incomplete resection of lung cancer surgery. At present, it is recognized that low volume of Ⅰ, Ⅱ and ⅢA tumors are suitable for surgical treatment, while high volume of ⅢA tumors and stage IIIB tumors need to be treated by adjuvant therapy to lower the stage before surgical treatment. Among the surgical methods used: anatomical lobectomy plus systematic hilar mediastinal lymph node dissection should be chosen.
3.Actively carry out expanded surgical treatment for locally advanced lung cancer. Expanded resection surgery can be performed for T4 (locally advanced) N0-2. The 5-year survival rate is 20.8%-33.1%.
4. Adjuvant chemotherapy has become accepted by the majority of lung cancer surgeons in China. For NSCLC after complete resection, a platinum-containing 2-drug regimen should be given, and patients receiving this regimen have an absolute benefit of 15% overall survival at 5 years.
V. Prevention of lung cancer
The prevention of lung cancer includes the following aspects.
1.Non-smoking and smoking cessation.
(1) Organized and planned health education among the public on the harmful effects of smoking and the need to resolutely refrain from smoking and quit smoking to prevent cancer. Beginning in elementary school in the curriculum to add the health hazards of smoking.
(2) Medical personnel, school teachers, literary and sports workers, journalists, and leading cadres at all levels should take the lead in not smoking and serve as role models for the general public.
(3) Health departments, education departments, news agencies and mass organizations should carry out publicity and education on the harmful effects of smoking.
(4) Take measures to ban smoking in all public places. Since the 1960s, countries such as the United Kingdom and the United States have vigorously publicized the health hazards of smoking, so that the smoking rate among the population has been declining at a rate of 1 to 2% per year, and the incidence of lung cancer in these countries, which has been rising year by year, has begun to be stopped or gradually declined in the 1990s. No matter how many years you have been smoking, whether you have lung cancer or not, and no matter how old you are, it is in your best interest to make up your mind to quit smoking immediately. The cancer-causing toxins deposited in your body will gradually decrease after you quit smoking. If you are a patient, quitting smoking will strengthen your healing process. Quitting smoking can restore your immune function, enhance your strength, and prevent cancer and other diseases.
2.Prevention of occupational lung cancer.
(1) Government departments should supervise and manage industrial and mining enterprises.
(2) Reform the production process, reduce dust and smoke, reduce the concentration of harmful substances in the environment, continuously improve the degree of automation, mechanization and confinement of production, and producers avoid or reduce direct contact with known carcinogenic factors.
(3) Strengthen personal protection, pay attention to formal operation during production, change out of work clothes after production, wash and shower, and do not take home work clothes.
(4) Regularly monitor the concentration of harmful substances in the environment, which should not exceed the national allowable standards, and take effective protective measures in a timely manner.
(5) Regular medical checkups, if occupational-related precancerous lesions or early cancers are found, they should be treated promptly and transferred away from the occupational environment with carcinogenic factors.
3.Prevention of environmental pollution.
In 1991, the State Council promulgated the Rules for the Implementation of Air Pollution Prevention and Control, which plays a very important role in preventing lung cancer and other related diseases. Its main contents are.
(1) people’s governments, industrial and mining enterprises, construction projects should be to prevent air pollution into the production and construction and technological transformation plans, to strengthen supervision and management.
(2) air pollution prevention and control facilities and regulations are accepted and qualified before the construction project can be put into production or use.
(3) prevention and control of smoke and dust pollution.
(4) new residential areas should implement combined heat and power supply, or centralized heating, promote low-pollution combustion technologies, and gradually limit the burning of loose coal.
(5) prohibit new construction projects in residential areas containing toxic emissions and dust, which have been put into production should be purified.
(6) due to special circumstances, the need to burn asphalt, linoleum, rubber, plastic, leather and other substances that produce toxic and harmful gases in concentrated areas of the population, subject to the approval of the local environmental protection department, and set up incinerators to focus on burning. Building construction needs to melt asphalt, the use of fixed melting devices should be enclosed.
(7) government environmental protection departments at all levels of motor boat exhaust pollution prevention and control to unify supervision and management. Exceed the national pollution emission standards for vehicles, shall not be manufactured, sold or imported.
(8) There are violations of national regulations are legally responsible.
4, control of indoor smoke and other pollution.
(1) indoor coal stove, coal stove to have a chimney, to keep the stove airtight. Chimneys should be swept frequently and kept clear.
(2) gradually replace coal-fired heating and cooking with gas.
(3) keep the kitchen ventilation, the kitchen should be installed hood or exhaust phoenix fan, ignition while opening the hood or exhaust phoenix fan.
(4) When cooking, do not exceed 200 degrees, do not let the frying pan smoke, use less frying cooking methods, and use refined oil as cooking oil.
(5) living room and bedroom should be separated from the kitchen to avoid polluted kitchen air into other living rooms.
(6) Use non-polluting materials for interior decoration and decoration. In order to prevent harmful substances emitted from decoration materials from harming residents, ventilation should be done for one month after the decoration is finished before starting to live in the house.
5. Control indoor radon pollution.
(1) Architecturally speaking, a dense barrier should be built to avoid radon infiltration into the room. Usually a cement barrier without cracks and holes is enough to block radon infiltration. Good ventilation condition is also an important link to control radon pollution.
(2) Strictly choose the foundation before house construction, ask relevant departments to do radon test if necessary, and then take radon reduction measures. Pay attention to the radioactivity of building materials and choose qualified building materials.
(3) Personally, when purchasing a house, first find out whether the area where the house is located belongs to the area with high content of radon in the stratum, and avoid purchasing a house in such area.
(4) Choose building materials with low content of radioactive substances as decoration materials.
(5) Fill and seal the cracks on the floor and walls.
(6) Use basement as living room or workplace, make sure to monitor indoor radon concentration, and those with too high radon concentration should not be used as living room or workplace.
6.Dietary prevention and chemical prevention
American Ma Chang and other studies confirmed that eating more various green leafy vegetables and tomatoes (tomatoes) has a significant protective effect on preventing lung cancer. Researchers have observed that lutein, lycopene and indole and other vegetable components in vegetables have anti-cancer effects on humans. Ziller et al. found that cruciferous vegetables (e.g., rape, cauliflower, cabbage, Chinese cabbage, kale, cauliflower, and turnip greens) were more protective against lung cancer. The American Institute for Cancer Research and the Institute of Oncology of the Chinese Academy of Medical Sciences, in a study of lung cancer in Yunxi miners, found the same results as above, in addition to the protective effect of onions and garlic against lung cancer, the active ingredients of which may be carotenoids and their complexes. In the study at the mine, it was found that eating more tofu and moderate amounts of meat and eggs also had a protective effect.
Increasing the intake of vegetables and fruits in food, especially more foods rich in carotenoids, vitamin C, vitamin E, folic acid, and the trace element selenium, can reduce the incidence of lung cancer. High-fat and high-cholesterol diets and alcohol consumption can increase the risk of lung cancer.
Vitamin A maintains the integrity of cell membranes, maintains normal metabolism of epithelial tissues, blocks the process of cellular carcinogenesis, accelerates nuclear DNA repair, and has a regulatory effect on gene expression. Graham’s study in a multi-ethnic Hawaiian population found that those who consumed less than 25,000 IU of vitamin A per month had a higher risk of developing squamous lung cancer than those who consumed greater than 150,000 IU per month.
Derivatives of vitamin A and carotenoids and carotenoids have attracted more attention for lung cancer prevention. Hunan Cancer Hospital reported in 1989 that domestic vincristine (RI) and vincristine (derivatives of vitamin A) were applied in two mines in Hunan in 1984 to treat moderate or severe atypical hyperplasia of sputum cells. The general condition improved after treatment, and the immunoglobulin IgA and IgM in the blood were elevated. The incidence of lung cancer in the treatment group and the control group was 1 to 4, and the mean grade of hyperplastic cells decreased, suggesting that this product has some efficacy in chemoprevention.
7.Living a regular life, having a happy mood, combining work and rest, and exercising to increase the ability to prevent and fight diseases.
8.Residents above middle-aged should have regular health check-ups
When symptoms such as irritating dry cough and blood in sputum appear, they should go to hospital for examination in time. If someone in the family has suffered from lung cancer, other members should pay attention to it and should have regular checkups.
In particular, people who usually smoke more than one pack a day and have smoked for more than 20 years are at high risk of lung cancer. If you have any suspicious symptoms, you should not take it lightly and go to the hospital for chest X-ray or CT examination. Pathological examination of sputum is also a good screening method, which can detect cancer cells and the confirmation rate can reach about 85%. For suspicious bloody sputum or blood sputum, or sputum with rotten flesh-like material, pathological examination should also be performed as soon as possible, so that the examination rate of cancer cells can be greatly improved. Nowadays, the widely used fiberoptic bronchoscope can directly observe the changes of bronchial lining and lumen, and biopsy the suspicious tissues for pathological examination, which is very helpful for early diagnosis of cancer. It is worth noting that 15% of lung cancer patients have no symptoms at all in the early stage. Therefore, regular annual chest X-ray examination for middle-aged and elderly people is of positive significance for the early diagnosis of lung cancer.
In conclusion, the prognosis of lung cancer depends on early detection, early diagnosis and early treatment. Once early lung cancer is diagnosed, timely surgical treatment can achieve the purpose of restoring health.