Cancer is a new organism in the human body (that is, something that should not exist under normal circumstances). This new organism is composed of a group of cancer cells that do not develop freely with physiological needs. Cancer cells do not have the function of normal cells. Because of its rapid and irregular growth, it not only consumes a lot of nutrients in human body, but also destroys the organizational structure and function of normal organs.
The process of transforming normal cells into cancer cells is called "canceration". So far, the cause and process of canceration have not been fully understood, but most scientists think it is \ "gene mutation \" or \ ".
Genetic dysfunction. " There is a natural gene in human cells that can cause cancer. Under normal circumstances, oncogenes are not only harmless to human body, but also play an important role in cell growth. However, when oncogenes are repeatedly influenced by external carcinogenic factors (such as rays, viruses, chemicals, etc.). ), the static oncogene in the cell is activated, the gene structure is mutated, the normal cell function is rebelled, and the cell becomes cancerous. In addition to invasive growth, cancer cells can also spread to other organs and tissues through other ways, causing the same tumors in these tissues and organs. This situation is called "transfer".
Second, what factors can lead to cancer?
The symptoms of cancer are various, but there are only two factors that cause cancer.
(A), in vitro factors
Physical carcinogenic factors: mainly ionizing radiation, ultraviolet rays, fibrous substances (such as asbestos mesh, glass fiber, etc. ), thermal radiation, long-term chronic mechanical stimulation, chronic inflammatory stimulation, trauma and long-term foreign body stimulation.
Chemical carcinogens: Up to now, more than 1 100 chemicals have been found to have carcinogenic effects on experimental animals, and 20 of them have carcinogenic effects on humans.
Biological carcinogenic factors: mainly the following:
Mould: The occurrence of some tumors is related to mycotoxins in food.
Viruses: It has been found that viruses above 150 can cause nearly 30 kinds of animal tumors.
Parasites: primary liver cancer and colorectal cancer are related to schistosomiasis; Primary liver cancer is related to liver fluke disease; In Egypt, bladder cancer is associated with schistosomiasis.
Bacteria: It is generally believed that bacteria themselves are not carcinogenic factors, but some bacteria can reduce nitrate to nitrite, which may be converted into ammonium nitrite.
(2) Internal factors
1. Genetic factors: According to the genetic law of the great biologist Mendel, scientists have made repeated studies and finally come to the conclusion that among many malignant tumors, only retinoblastoma is heritable, and only about 40% of all retinoblastomas are heritable.
2, secretory factors: the human body has many endocrine glands that secrete hormones, and they secrete various hormones to maintain the normal activities of the human body. When these hormones are secreted too much or too little, endocrine disorders will occur, causing related diseases.
3. Immune function: Simply put, immune function is the ability of human body to resist diseases. People with congenital immunodeficiency are more likely to get cancer than normal people. Because of the long-term use of immunosuppressants in kidney transplantation, the incidence of cancer is 100 times higher than that of normal people. Everyone is exposed to carcinogens more or less all the time, and cell canceration is possible.
4. Mental factors: The American Anti-Cancer Association pointed out that mental factors have an important impact on the immunity of patients who rely on anti-cancer; Chinese medicine believes that breast cancer is related to "depression" and esophageal cancer is a "disease of fatigue".
3. What are the early signs of cancer?
It is generally believed that cancer lacks aura and has no obvious symptoms, but clinical practice has proved that early cancer still has many aura symptoms:
Unexplained emaciation, weakness, irregular pain in the upper abdomen, loss of appetite, especially anorexia to meat.
Non-pregnant women and lactating women have pus on their nipples or can squeeze out juice.
Any part of the body, such as the breast, neck or abdomen, will have a growing lump.
Dry cough, bloody sputum, chest tightness and chest pain, which can not be cured for a long time.
For women over middle age, vaginal bleeding is small after sexual intercourse, or irregular vaginal bleeding at ordinary times, or menstruation and leucorrhea increase obviously after menopause for several years.
Jaundice gradually deepened, with a mass in the upper abdomen and no abdominal pain.
Hepatomegaly is rapid and accompanied by pain in the liver area.
Painless hematuria of unknown cause.
The skin festers and cannot heal for a long time.
The nevus suddenly increases, accompanied by burning pain, ulceration, bleeding pain or hair loss.
Recurrent fever and intractable tooth bleeding, subcutaneous bleeding and progressive anemia.
Recurrent unexplained high fever.
Oral mucosa, or female vulva or male penis glans appear white spots, which quickly expand and burn itchy discomfort.
Progressive weakness, paresthesia, dyskinesia or incontinence of both lower limbs.
There is no obvious fracture of femur and humerus caused by external force.
When eating and swallowing, there is a foreign body infarction behind the sternum, stinging or conscious food passing slowly.
Nasal congestion, frequent nosebleeds or nosebleeds, accompanied by migraine, dizziness, tinnitus and lymph node enlargement in the upper neck and lower earlobe.
The habit of stool changes, or diarrhea and constipation often appear alternately, and stool often carries pus and blood, or stool becomes thin and flat.
Headache worsens with sudden and temporary visual impairment and vomiting.
Teenagers have severe pain and swelling in elbow or knee joint, but it is ineffective to treat with anti-rheumatic drugs or antibiotics.
The above 20 representative items can be suspected to be symptoms of malignant tumors. Anyone who finds these symptoms should pay enough attention and go to the hospital for diagnosis as soon as possible.
Fourth, early warning signals of various common cancers.
(1) Esophageal cancer:
I feel suffocated when I swallow food.
Pain behind the sternum, esophageal pain when swallowing.
Foreign body sensation in esophagus.
Food delivery is slow and there is a sense of detention.
My throat feels dry and tight.
There is a feeling of tightness behind the sternum.
(2) Gastric cancer:
Above middle age, no previous history of stomach trouble, sudden loss of appetite, epigastric pain or persistent dull pain.
Have a medical history, especially the ulcer of stomach angle and minor curvature. The previous law of mild pain suddenly changed, and the treatment effect was not good according to the primary disease.
Had gastrectomy, postoperative gastric stump cancer.
The original atrophic gastritis, recently appeared wasting anemia, aversion to oil and indigestion symptoms aggravated.
No history of stomach disease and liver disease, sudden vomiting, anemia, or stool occult blood positive for more than two weeks.
Unexplained progressive wasting and anemia.
For people over 40 years old, the ulcer is located in the small curvature of gastric antrum, and there are intestinal metaplasia and multiple gastric polyps in pylorus, especially adenomatous polyp. We should strive for early treatment to avoid canceration.
(3) Breast cancer
Breast lump: the disease is asymptomatic in the early stage, and breast lump is often found during dressing, bathing, physical examination or self-examination.
Nipple discharge: often bloody, but also milky white, serous, watery and so on. And most of them are unilateral mammary gland secretions.
Nipple changes: according to the location and depth of the lesion, there are different degrees of changes.
The first symptom of individual patients is axillary lymph node enlargement.
(4) Liver cancer
The frequency of symptoms of liver cancer is as follows: epigastric pain, anorexia or anorexia, emaciation, fatigue, abdominal mass, epigastric fullness and fever.
The first symptoms of liver cancer can generally be divided into the following six groups of syndromes:
He has a history of hepatitis and cirrhosis, and his condition has been stable for many years. He has no sudden dull pain or severe pain in the liver and bile area caused by chills and fever.
For adults over 30 years old, the right upper abdomen can be lumpy, hard and uneven, and the continuous observation shows an obvious increasing trend, but the patient has no obvious discomfort.
Dry mouth, irritability, insomnia, gingival bleeding, nosebleed, accompanied by fullness of the stomach and liver discomfort.
Physical and joint pain, especially back pain, accompanied by anorexia, irritability and liver discomfort. Anti-rheumatic treatment has a poor effect.
Recurrent diarrhea, accompanied by indigestion and abdominal distension, is not effective or incurable according to gastroenteritis, and the liver area is gradually wasting away.
Family history of cancer, especially those with close relatives of liver cancer.
(5) Lung cancer
1, cough 2, blood sputum 3, chest pain 4, shortness of breath 5, fever 6, other extrapulmonary symptoms except the above symptoms.
(6) Cervical cancer
Contact bleeding: manifested after sexual intercourse or during gynecological examination in Shuanghe town.
Irregular vaginal bleeding: manifested as a small amount of non-menstrual vaginal bleeding between menstruation and postmenopausal vaginal bleeding.
Abnormal leucorrhea: mostly manifested as the increase of leucorrhea, followed by the change of color and smell.
(7) Pancreatic cancer
Upper abdominal discomfort and abdominal pain (tumor can compress bile duct and pancreatic duct), painless skin and sclera yellow staining gradually deepen, generally no chills and fever.
Loss of appetite, fatigue and progressive emaciation.
Gallbladder enlargement caused by obstructive jaundice can be palpated in the right upper abdomen.
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5. Who is prone to cancer?
People who are allergic to drugs or chemicals are more likely to develop cancer than those who have no allergic history.
People who often stay up late, it is the most vigorous period of cell fission, sleep is not good, it is difficult to control cell mutation and form cancer cells.
Obesity research data show that obese women have twice the risk of colon cancer as ordinary women. Women who are particularly obese above the waist are 4-6 times more likely to develop breast cancer than normal people.
People with vitamin deficiency and vitamin A deficiency have a 3.5-fold increase in the risk of gastric cancer and a 2-fold increase in the risk of other cancers. Among people with vitamin E deficiency, the prevalence rates of lip cancer, oral cancer, pharyngeal cancer, skin cancer, cervical cancer, gastric cancer, intestinal cancer and lung cancer all increased.
Cholesterol is an important force to resist diseases, but the lower the cholesterol, the better. British researchers report that an important factor in the death of middle-aged and elderly women is low cholesterol, especially when it is less than 5 mmol per liter, which is the most dangerous.
There is a carcinogen in the urine of people who suppress defecation, which will invade the muscle fibers of the bladder and promote cancer; There are many harmful substances in stool, such as indole, hydrogen sulfide and other carcinogens.
Sixth, the relationship between cancer and occupation.
Some survey results show that cancer is not a civilized disease compared with people in high-level society and low-level society. Because in the so-called upper class, people who live a more civilized and progressive life have a low cancer mortality rate; On the contrary, the lower the social class, the higher the cancer mortality rate.
According to statistics, people suffering from colorectal cancer, gallbladder cancer and pancreatic cancer are not divided into classes, and the incidence of each class is roughly the same. However, an informal report pointed out that the death rate of teachers, general technicians, people engaged in specialized occupations or management occupations was low due to gastric cancer, lung cancer and leukemia. Including medical-related health care technicians, such as doctors and nurses, there are fewer people suffering from gastric cancer and more people suffering from lung cancer and leukemia. As for artists and entertainers, the lung cancer rate is quite high, second only to metal material manufacturing and mining.
The industries prone to stomach cancer, lung cancer and leukemia are: metal material manufacturing, mining, agriculture, forestry and fishery. Surprisingly, the incidence of cancer in general workers is slightly higher than that in managers or professionals, while the incidence of lung cancer or leukemia is much higher than that in sales staff.
It can be seen from this statistics that people engaged in the primary industry, such as metal material manufacturers, miners, farmers, forestry and fishermen, are most likely to get cancer. As for the secondary industry, such as silk making and textile, the cancer rate is much less. The technicians who use metal materials to make motor products or install machinery have a lower cancer rate than other simple workers. In addition, the cancer rate of service providers is also low. However, people engaged in printing, chemical industry and food are more likely to suffer from lung cancer and may inhale toxic substances during operation.
7. What are the bad habits of walking with Cancer?
(a), partial to meat.
Experts from Harvard University in the United States found that the proportion of women who live on livestock meat such as pigs, cows and sheep every day is 2.5 times higher than that of women who live on vegetables and bean products every day. Because too much fat intake can easily lead to the decline of immune function, so that cancer cells can take advantage of it.
(2) Drink hot strong tea
Drinking tea with high temperature (above 80℃) often may burn the esophagus, and tannin in tea will be deposited on the injured part, which will constantly stimulate esophageal epithelial cells and make them mutate. Mutant cells can become cancer tissue after massive proliferation.
(3) Don't eat vegetables
Disliking vegetables can easily lead to vitamin and fiber deficiency in the body. Vitamins are the power to maintain life, while cellulose can clean the intestines and prevent the invasion of gastric cancer, colon cancer and rectal cancer.
8. Is cancer contagious and hereditary?
After years of medical research by many experts at home and abroad, the following conclusions are drawn: cancer is not contagious and will not be inherited! Although cancer cells can spread and metastasize around patients, they will not spread from one person to another like bacteria and viruses. For yourself, other people's cancer cells are a foreign body, and the body destroys cancer cells through strong immune rejection. So other people's cancer cells can't spread to their own bodies to survive.
Infection and heredity are two completely different concepts. Infection is an infectious disease caused by bacteria or viruses, such as tuberculosis and hepatitis; Heredity is due to blood relationship, which makes many people in the family suffer from the same disease. According to the genetic law of the great biologist Mendel, after repeated research, scientists finally came to the conclusion that among many malignant tumors, only retinoblastoma is heritable, and only about 40% of all retinoblastoma is heritable.
Nine, how to transfer cancer? What are the factors of transfer?
Metastasis means that malignant tumor cells fall off from the primary tumor, reach the discontinuous part through various ways, and continue to grow to form new secondary tumors with the same properties. This feature of malignant tumor should be called diffusion. Diffusion should include infiltration and transfer, because transfer must be preceded by infiltration, so transfer is a serious consequence of infiltration. Malignant tumors metastasize through lymphatic channels, blood circulation and implantation. The main factors of cancer metastasis are as follows:
(1) Degree of tissue differentiation: The lower the degree of differentiation, the more obvious the infiltration and the earlier the metastasis.
(2) Characteristics of metastatic organs: Cancer is generally easy to metastasize to organs with rich blood supply, such as bone, liver, lung and brain.
(3) Mechanical stimulation of primary cancer: The tumor formed by malignant tumor, especially vascular sarcoma, can make cancer cells enter the blood system and increase the risk of metastasis.
(4) Physical condition: Patients are generally in poor condition or have low immune function. Will increase the chance of cancer metastasis.
10. What are the modes and routes of cancer transmission?
Cancer cells spread in the human body, often in a variety. The main routes are direct reproduction and reaching distant organs through lymph and blood circulation system. These diffusion methods can be carried out separately or simultaneously.
(1) The direct spread of cancer is a natural way of early development.
(2) Lymphatic diffusion Cancer spreads through the lymphatic system, which is extremely common and important. The long-distance spread of cancer is mainly through the lymphatic system.
(3) Tumor tissue with blood flow diffusion can infiltrate the blood vessel wall, form tumor embolism, and spread along the blood flow. Whether the blood supply around the original lesion is rich or not has a certain relationship with the spread of cancer.
(4) Cancer Planting Cancer cells can be planted and grown in nearby organs and tissues, especially in places with wounds. In gynecological tumors, papillary ovaries are often implanted on the peritoneum after breaking through the capsule.
XI。 What is primary cancer? What are recurrent cancer and metastatic cancer?
Primary cancer refers to the normal cells of normal tissues and organs, which gradually turn into cancer cells under the long-term action of various internal and external carcinogenic factors, and then form cancer cells, that is, "primary cancer" or "primary tumor"
Recurrent cancer means that after the primary cancer has subsided after treatment, a new tumor grows on the organ where the primary cancer is located. The new tumor is called recurrent cancer.
Metastatic cancer is that cancer cells invade blood vessels, lymphatic vessels or body cavities from the primary site, run with blood or body fluids, and form the same type of cancer as the primary cancer in distant sites or organs. Metastatic cancer must meet two conditions: first, the site must be far away from the primary cancer; Second, the nature of cancer must be the same as that of primary cancer.
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Cancer is preventable.
1, Professor Yang Binghui, Vice President of China Health Education Association (left)
2. Movie actor Li Lan (right)
Moderator: Hello, audience friends! This is CCTV's live program "The Road to Health". Today we are going to talk about cancer prevention. First of all, let's look at a set of data: in the next 20 years, the number of new cancer patients in the world will increase from the current 6.5438+million to 50 million, and the number of cancer deaths will increase from 6 million to 6.5438+million. This is a very heavy set of data. Today we will talk about how to prevent cancer.
Moderator: Can cancer be prevented? First, let's watch a survey video:
Mass A: I don't think cancer can be prevented, because if it can be prevented, so many people won't get cancer.
Mass B: I don't think cancer is an infectious disease, and it can't be prevented.
Mass C: I think that with the rapid development of science and technology, cancer should be preventable, but I can't say clearly how to prevent it.
Yang Binghui: When a citizen talks about the prevention and treatment of infectious diseases, I want to talk about vaccination against smallpox. After the popularization of this preventive method, smallpox was eliminated worldwide. Many people think it would be great if cancer could be prevented by a method similar to vaccination. Unfortunately, there is no such method to prevent it at present, and even if there is, it may not be able to solve the comprehensive problems in the future. Because there are many causes of cancer, and a large part of them are closely related to our life behavior, it is very important to prevent cancer not by taking the so-called vaccine, but by changing our life behavior.
Moderator: What is the relationship between lifestyle and cancer?
Yang Binghui: Oncologists have noticed that there are many causes of cancer, including heredity and occupation, but most of the causes of cancer (80%) are in our daily life, so we put forward a concept called "lifestyle cancer", which actually means that people should pay attention to their lifestyle.
Moderator: What is the specific lifestyle problem you understand?
Li Lan: I think first of all, smoking is a bad lifestyle.
Yang Binghui: Smoking is closely related to cancer. Our research shows that the possibility of smokers suffering from lung cancer is 8- 12 times that of non-smokers. There are about 600 kinds of harmful substances in cigarettes, of which about 40 kinds have been proved to be carcinogenic. Smoking may not only cause lung cancer, but also affect the throat, esophagus and bladder.
Moderator: Is there any specific data that can explain the harm of smoking?
Yang Binghui: The incidence of lung cancer in many countries in the world, including China, is increasing, but the report on the incidence of lung cancer in the United States released by the American Cancer Institute at the beginning of this year is very worthy of attention. The incidence of lung cancer in the United States also increased before the 1990s, and tended to be flat after the 1990s. However, since 1996, the incidence of lung cancer has decreased by 0.4 percentage points every year. In addition, the year before last, the European side also suggested that their incidence of lung cancer began to decline. So what is the reason? According to themselves, this is closely related to the improvement of life behavior represented by tobacco control. In the 1960s, there were many smokers in the United States, accounting for about 46% of the total population. After 30 years of hard work, the proportion of smokers has dropped to 24%, so their incidence of lung cancer has also dropped. I wish China could do such a good job in tobacco control.
Among the many causes of cancer
Dietary factors account for 35%
Tobacco accounts for 30%
Drinking accounts for 3%
Sex and reproduction account for 7%
Food additives account for 1%
Drugs accounted for 1%
other
Li Lan: I would like to ask, is it possible to cause cancer by eating fried food frequently?
Yang Binghui: Too much greasy diet will not only lead to arteriosclerosis and coronary heart disease, but also be related to cancer, especially intestinal cancer. Twenty years ago, the incidence of colorectal cancer in Shanghai ranked sixth among all kinds of cancers. In the past 20 years, with the improvement of living standards, the oil content in food has increased significantly, so the incidence of colorectal cancer has risen to the fourth place. Some people think that a high-fat diet will also promote breast cancer. Foreign studies show that high-fat diet may be related to prostate cancer and pancreatic cancer.
Li Lan: You must put oil in your cooking. What oil is better to eat?
Yang Binghui: Many people used to think that animal oil (meat oil) should be eaten less, but from the perspective of cancer prevention, vegetable oil should also be controlled. Some light dishes in the south, such as steamed vegetables and soup, are very healthy.
Li Wei: I read an article in a magazine that eating potatoes and sweet potatoes can prevent cancer. Is that so?
Yang Binghui: There is some truth in this statement, because foods like potatoes and sweet potatoes are rich in cellulose, which is basically not digested and absorbed by the human body. One advantage is that the potential harmful substances in the intestine can be discharged in time. Therefore, we advocate that the diet should not be too delicate and rough, not only from the perspective of nutrition but also from the perspective of cancer prevention, especially the prevention of intestinal cancer, which has many benefits.
Moderator: Is there any data showing that changing eating habits is helpful to health?
Yang Binghui: What we advocate is that eating more fresh vegetables and fruits is good for your health and good for cancer prevention.
No one's daily vegetable intake
From 150g to 400g.
The risk of lung cancer can be reduced by 50%
From 100g to 350g.
The risk of gastric cancer can be reduced by 60%
From 50 grams to 300 grams
The risk of gastric cancer can be reduced by 50%
Changing diet can prevent
50% of breast cancer
75% of gastric cancer
75% of colon cancer
Li Lan: I also have the habit of eating jiaozi. jiaozi has just been fished out of the pot. I think it's very comfortable to eat like this. Is that so?
Yang Binghui: This way of eating is wrong. Eating too hot food is easy to damage the mucosa of esophagus. Eating too hot food often leads to chronic inflammation of the esophagus. Many oncologists' research shows that cancer actually develops on the basis of chronic inflammation.
Moderator: Northerners like to eat pickled sauerkraut. Is there a relationship between eating Sichuan kimchi and cancer?
Yang Binghui: Sauerkraut, pickles and pickles all contain a substance called nitrite. Nitrite can combine with ammonia decomposed by protein in human body to form nitrosamines, which is definitely an important factor in the formation of esophageal cancer. I suggest you eat less sauerkraut, pickles and pickles.
Moderator: After talking about food, let's talk about what we usually drink, such as drinking, will it cause cancer?
Yang Binghui: Actually, alcohol is not a carcinogen, but it will promote cancer. I have done such research. Through the investigation of hepatitis patients, I found that people who had hepatitis and gave up drinking were less likely to develop liver cancer, while those who had hepatitis and drank alcohol were twice as likely to develop liver cancer as those who did not drink alcohol.
Li Lan: Some people say that everyone actually has cancer cells, but some people show it and some people don't. Is this correct?
Yang Binghui: No, the medical definition is that as long as cancer cells are detected, cancer can be diagnosed. However, the human body has proto-oncogenes that will explode under the impetus of carcinogens and then produce cancer.
Moderator: mr. yi, a native of Hunan, is 37 years old. I am a patient with hepatitis B, and I always feel liver pain recently. Will I get liver cancer in the long run?
Yang Binghui: The risk factors of liver cancer in people with hepatitis B are definitely higher than those without hepatitis B. ..
Moderator: Ms. Lu from Beijing, 40 years old. I have been suffering from stomach trouble for 4 or 5 years. I feel a stomachache before and after meals. Can stomach disease continue to deteriorate and cause cancer?
Yang Binghui: There is a clinical phenomenon that duodenal ulcer has little to do with cancer, but gastric ulcer is always bad, and it is still possible to develop into cancer.
References:
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