One by one, we spend money to invite more than 40 types of cancer into our lives...

What do we gain from smoking?

My mouth was full of the stink of cigarettes, my teeth were yellowed, and I had a disgusting odor all over my body.

What’s worse is that we spend money to fill our bodies with many kinds of carcinogens, inviting cancer into our lives. Related research shows that there are more than 40 kinds of carcinogens produced by smoking that can directly cause cancer.

Statistics from the World Health Organization show that the number of people who die from smoking each year is as high as 6 million worldwide, and in my country the number has exceeded 1 million.

Before discussing the relationship between cigarettes and cancer, our experts would like to give a brief introduction to the occurrence of cancer.

Wang Zhiqiang, deputy director of the Chest Tumor Center of Chongqing Cancer Hospital

Ji Xiaohui, Department of Oncology, Chongqing Cancer Hospital

Zhang Qing, Gastrointestinal Tumor Center, Chongqing Cancer Hospital

“

Let's compare cancer to a "demon". It was originally locked in a cabinet, hidden in a corner of the human body, and this cabinet has more than one lock. If the "demon" wants to get out, it must have the keys to each lock at the same time. These keys, which are what we usually call carcinogenic factors, usually include genetics, environment, spirit, chemicals, etc. The more keys there are, the greater the chance of opening the cabinet. And cigarettes are one of the keys. During the burning process of cigarettes, the temperature can reach 900-1000℃, resulting in a series of decomposition and synthesis chemical reactions, forming nearly 4,000 new chemical substances. Most of these substances are harmful to humans, among which nicotine, nitric oxide, and tobacco tar are the most harmful, and the latter is the culprit of cancer.

”

Previous studies have shown that nicotine is a weak carcinogen, but more and more studies have found that nicotine plays a role in promoting the occurrence and development of tumors. When smoking, harmful substances invade the epithelium, destroy the function of epithelial cells, and cause changes in the body's molecular structure, causing disease.

After the harmful substances in cigarettes enter the human body, they can cause cancer through the following ways:

① Free radical oxidative stress;

② Directly lead to mutations in oncogenes and tumor suppressor genes;

③ Smoke activates carcinogenic metabolic enzymes;

④ Damage and imbalance in the expression of inflammatory cytokines.

Respiratory system

1

Nasopharyngeal cancer:

12% of nasopharyngeal cancer is related to smoking; heavy smokers have a 2-4 times higher risk of nasopharyngeal cancer than non-smokers, and the more they smoke and the longer they smoke, the higher the risk. If you are in a passive smoking environment for a long time, your risk of nasopharyngeal cancer will also increase.

2

Laryngeal cancer:

Smoking is an important high-risk factor for laryngeal cancer. Smokers are 39 times more likely to develop laryngeal cancer than non-smokers. The younger you start smoking, the more you smoke every day, and the longer you smoke, the higher your risk of laryngeal cancer.

According to epidemiological surveys, about 88%-98% of laryngeal cancer patients have a long history of smoking, and more than half of them smoke more than 20 cigarettes a day.

3

Lung cancer:

Epidemiological surveys show that smokers are 13 times more likely to develop lung cancer than non-smokers. If they smoke more than 35 cigarettes a day, their risk is 45 times higher than that of non-smokers. The lung cancer mortality rate of smokers is 10-13 times higher than that of non-smokers. About 80% of lung cancer deaths have a history of heavy smoking.

Domestic and foreign studies have shown that the earlier you start smoking, the longer you smoke, the more you smoke per day, and the deeper you smoke, the higher your risk of lung cancer. A domestic study showed that passive smoking in the work environment is the main risk factor for lung cancer in male non-smokers, and passive smoking in the home environment is the main risk factor for lung cancer in women.

Digestive system

1

Oral cancer:

Oral cancer rarely occurs in non-smokers. The occurrence of oral cancer is related to factors such as smoking, drinking, and viral infection. Studies have shown that about 75% of oral cancers are related to smoking.

Smoking is considered the most dangerous factor for the development of oral cancer. The site of oral cancer is related to the smoking method. For cigarette smokers, the site of disease is mostly on the tongue and the bottom of the mouth, for pipe smokers, it is mostly on the lips, and for snuff addicts, it is mostly where the snuff is placed. The incidence of oral cancer is positively correlated with the amount of smoking. Assuming that the risk of oral cancer for a non-smoker is 1, if he smokes 10-19 cigarettes a day, the risk rises to 12.4.

2

Esophageal cancer:

In my country, esophageal cancer is mainly squamous cell carcinoma, and smoking significantly increases the risk of esophageal squamous cell carcinoma. Epidemiological studies have confirmed the relationship between smoking and the incidence of esophageal squamous cell carcinoma, indicating that the incidence of esophageal squamous cell carcinoma in smokers is 5 times higher than that in non-smokers, and nearly 10 times higher in heavy smokers.

3

Gastric cancer:

In fact, smoking not only hurts the lungs but also the stomach. It can be said without hesitation that smoking is one of the main causes of stomach problems, delaying the healing of stomach problems, causing the recurrence of stomach problems and even causing stomach cancer.

According to research, when smokers smoke, some of the smoke enters the stomach or even the intestines through the digestive tract. The nicotine contained in the smoke directly stimulates the gastric mucosa, causing submucosal vasoconstriction and spasm, leading to ischemia and hypoxia of the gastric mucosa, destroying the gastric mucosal barrier, and causing gastritis and gastric ulcers.

At the same time, nicotine can also relax the pyloric sphincter, causing gastric motility disorders, and causing bile and duodenal fluid to reflux into the stomach, causing gastritis. Severe or long-term gastric diseases are high-risk for gastric cancer.

4

Liver cancer:

Smoking is the main independent risk factor for liver cancer. The risk of liver cancer in smokers is 1.5-3 times that of non-smokers.

Pancreatic cancer: Smoking is the only recognized risk factor for pancreatic cancer. 19% of pancreatic cancer cases can be attributed to smoking. The risk of death for smokers is 1.2-3.1 times higher than that for non-smokers.

Urogenital system

1

Kidney cancer:

Years of research have proven that smoking is a high-risk factor for kidney cancer. According to statistics from the American Institute for Cancer Research, the more you smoke and the longer you smoke, the higher your risk of kidney cancer. Not only does smoking increase the risk of kidney cancer, but environmental smoking, especially passive smoking at home or in the workplace, also increases the risk of kidney cancer. Compared with those with no history of passive smoking in the home environment for more than 20 years, those with a history of passive smoking in the home environment have a 2.18-fold increased risk of kidney cancer.

2

Bladder Cancer:

Smoking is currently the most confirmed risk factor for bladder cancer. About 30%-50% of bladder cancers are caused by smoking. Smoking can increase the risk of bladder cancer by 2-4 times, and the risk is proportional to the intensity and duration of smoking.

3

Cervical cancer:

Cervical cancer is one of the most common malignant tumors of the female reproductive system.

Studies have shown that higher levels of nicotine and cotinine (a carcinogen produced by cigarettes) can be isolated from the cervical mucus of active and passive smokers than from plasma.

These carcinogens play a key role in cervical lesions through immunosuppression mechanisms. In the cervical mucosa, there are a large number of immune cells, which build a strong immune barrier. The carcinogens in smoke can deform the DNA of immune cells, damage the immune barrier of the cervix, and then lead to repeated infection of the cervix with HPV (human papillomavirus, which causes cervical cancer), and eventually develop into cervical cancer.

In addition, smoking is also related to the occurrence of malignant tumors such as colorectal cancer, breast cancer and acute leukemia.

Text/ Fat Bear

Picture/ Internet

Reviewer/ Wang Zhiqiang/ Ji Xiaohui/ Zhang Qing

Original article, no reproduction without authorization

Chongqing Cancer Prevention and Treatment Science Popularization Base/Member of China Medical Self-media Alliance