Who is more likely to get cancer: a smoker or a drinker or a non-smoker or non-drinker? Why?

In early 2021, the World Health Organization's International Agency for Research on Cancer (IARC) released the latest global cancer disease burden data.

The latest data shows that in 2020, there were 19.29 million new cancer cases and 9.96 million deaths worldwide; in 2020, there were 4.57 million new cancer cases and 3 million deaths in my country. China has the highest number of new cancer cases in the world, accounting for 23.7%.

Corresponding to the data, there are more and more people suffering from cancer around us, and it is not uncommon for people to die from cancer. Some people actively treat cancer after they get it, but still die soon; some people ignore cancer after they get it, and live for a long time as if nothing happened. Why is this?

We all know that smoking and drinking increase the risk of cancer, but individual cases around us may conflict with this understanding. Sister Wang, who never smoked or drank, died of liver cancer in her 40s; Uncle Li, who smoked and drank for a long time, is now in his 80s and is still very healthy. Do these individual cases mean that smoking and drinking have no effect on the body? Therefore, a discussion has arisen: who has a higher risk of cancer, smokers and drinkers or non-smokers and non-drinkers? Let's discuss this issue together.

The causes of cancer are not fully understood at present. The causes of cancer are usually divided into two categories: endogenous factors and exogenous factors.

Exogenous factors:

1. Lifestyle habits are also called behavior-related factors. For example, smoking can cause lung cancer, heavy drinking can cause liver cancer, high-energy and high-fat diets can cause breast cancer, and lack of dietary fiber can cause colorectal cancer. Among the tumor risk factors released by the World Health Organization, smoking and drinking are related to many cancers.

2. Environmental pollution and occupational factors The current high incidence of lung cancer is closely related to environmental pollution. Water and food pollution can cause many cancers. For example, food contaminated by aflatoxin can cause liver cancer, and asbestos in the occupational environment can cause lung cancer.

3. Biological factors such as hepatitis B virus can cause liver cancer, HPV virus can cause cervical cancer, Helicobacter pylori can cause gastric cancer, Epstein-Barr virus can cause nasopharyngeal cancer, etc.

Endogenous factors:

1. Genetic factors: There are very few cancers that are truly inherited, but genetic factors can increase susceptibility to other carcinogenic factors. For example, some people can live to 90 years old even if they smoke all their lives, and some people who do not smoke still suffer from lung cancer at a very young age.

2. Immune factors Immune factors play an important role in the occurrence and development of tumors. There are oncogenes and tumor suppressor genes in human genes. When the immune function is intact, cancerous cells can be cleared in time. If the immune function is low and AIDS cells cannot be cleared in time, the body is prone to cancer. For example, after being infected with HIV, the immune system collapses and cancer is prone to occur.

3. Endocrine factors Abnormal hormone levels in the human body may also lead to certain cancers. For example, estrogen and prolactin are related to breast cancer, and growth hormone can stimulate the development of cancer.

In addition to the above-mentioned exogenous and endogenous factors, the occurrence and development of tumors are also related to factors such as personal mentality and whether one actively exercises.

Discussion of factors related to the occurrence of cancer The human body is a magical organization. Oncogenes and tumor suppressor genes exist in the human genes at the same time. Oncogenes and tumor suppressor genes are expressed all the time. At the beginning, the activity of oncogenes is not high. After gene expression, fewer cells become cancerous or the speed is slow. Oncosuppressor genes are actively expressed and can eliminate cancerous cells at any time, so the body will not develop cancer. The human immune system has three functions, namely immune defense, immune self-stabilization and immune surveillance. The function of immune surveillance is mainly to identify and eliminate cancerous cells in the body. When the immune surveillance function is normal, the body will not develop cancer.

As the human body ages or due to certain external factors, the immune function decreases, resulting in insufficient immune surveillance and failure to remove cancerous cells in time, which makes it easy for tumors to occur. If a person lives long enough, a tumor will eventually occur. Why is this so? The human body comes from a fertilized egg, and then the cells divide, divide, and divide again, eventually forming a human body. As age increases, the number of cell divisions increases, and the probability of errors in chromosome replication increases, which eventually becomes uncontrollable, resulting in cancer.

Factors that lead to reduced immune function Whether the immune function is normal is related to various diseases in the human body. There are many factors in life that can lead to reduced immunity.

First, mentality. The quality of mentality is directly related to the quality of immune function. People with a good mentality have better immune function and generally do not get cancer. Even if they do get cancer, the prognosis will be much better. "Type C" personality is also called depressive personality, and the risk of cancer will be much higher.

Second, whether you insist on exercising. For the prevention and treatment of any disease, we emphasize that you must insist on exercising if your body allows. Long-term exercise can promote the strength of immune function and is beneficial to the health of the body.

Third, personal life and work schedule. Adults should get 8-9 hours of sleep every day. Staying up late or lack of sleep for a long time will cause great damage to the immune function, and various health problems will occur over time. Friends, you can review the cases around you. Do people who stay up late for a long time have poor health?

There are many factors that lead to reduced immune function, such as irregular diet, malnutrition, HIV infection, etc., which are not elaborated here.

Why do some people who smoke and drink live a long life while others who do not smoke or drink get cancer? We have discussed above that cancer is caused by the combined action of multiple factors, among which there is a key point - the susceptibility of the body.

Whether a person gets cancer is related to the body's susceptibility. For example, Mr. Li's body is very susceptible to carcinogenic factors, so even if he drinks and smokes, the probability of getting cancer is also very low; Aunt Wang's body is very susceptible to carcinogenic factors, so even if she doesn't drink or smoke, the risk of getting cancer is also high. This also explains why some people who smoke and drink for a long time don't get cancer, while those who don't smoke or drink get cancer.

Life in modern society is stressful and the prevalence of depression is very high. Many people stay up late for a long time and have irregular eating and living habits. These factors will lead to a decrease in immunity, thereby increasing the risk of cancer.

We can think of the examples around us. In the past, in rural areas, some old men smoked leaf tobacco for a long time but were very healthy. When we got along with them, we found that they always had smiles on their faces, which showed that they had a very good mentality. This also brought us inspiration for cancer prevention and control work.

The occurrence and development of cancer is the result of the interaction of multiple factors. I hope everyone will pay attention to cancer, prevent cancer, and live a healthy and happy life every day!

I’m Dr. Bobo. If you have any health-related questions, you can follow me and send me a private message for consultation. Thank you!