[Fat Bear Science] Is cancer contagious? Is "family cancer" common? All the knowledge about cancer transmission in one article

In recent years, cancer has attracted more and more attention.

While people are preventing cancer, they are also concerned about whether cancer is contagious?

Are “family cancers” such as those among couples and children prevalent?

Today, Fat Bear is here to talk to you about these things.

1 Is cancer contagious?

The answer is a definite yes, it is definitely not contagious.

The onset and occurrence of cancer is the result of changes in one's own cell genes under the combined action of multiple external factors such as environment, living habits, diet and exercise.

The latest research shows that genetic factors, as an internal factor, play a certain role in the occurrence of some cancers, such as breast cancer, ovarian cancer, and colorectal cancer (but genetics is not the most important role. Pang Xiong has previously popularized the issue of genetics, click here).

Let’s first look at how cancer occurs?

There are two kinds of genes in human cells, proto-oncogenes and tumor suppressor genes. Once activated, proto-oncogenes will turn into oncogenes, which cause cell growth and proliferation. In contrast to oncogenes, tumor suppressor genes can inhibit cell growth and proliferation. After tumor suppressor genes mutate, they lose their ability to inhibit cell growth and proliferation. Oncogenes and tumor suppressor genes have opposite effects, but both promote the occurrence of cancer. When the disorders of oncogenes and tumor suppressor genes are combined, cells will proliferate without limit, forming what we call cancer. In general, cancer occurs because of changes in cell genes.

Cancer should be considered a chronic disease. Under the long-term effects of external factors, human cells accumulate genetic damage and changes over a long period of time. This is a multi-factor, multi-stage, complex and progressive process. It usually takes more than ten years to several decades for normal cells to develop into cancer cells. This is why we say that everyone can effectively prevent it.

A large amount of statistical data shows that the incidence of cancer among doctors and nurses in cancer hospitals who have long-term contact with cancer patients is not higher than that of the general population. Chongqing Cancer Hospital organizes cancer risk screening for its employees every year. The incidence of cancer among hospital employees is not higher than that of cancer in Chongqing, and may even be lower (everyone knows how to prevent it).

If you think I am lying, then think about it, if the blood pressure is high, would anyone still work at Chongqing Cancer Hospital?

So far, there is no scientific research evidence internationally that can directly prove that cancer can be transmitted through daily lifestyle activities such as kissing, contact, sex, and sharing tableware.

2 Is "family cancer" common among couples and children? Can two people get the same cancer?

This is actually possible.

However, it is not the result of infection, but rather... the same lifestyle, diet structure, and environment.

As mentioned before, cancer is not contagious, but that does not mean that the viruses that cause cancer are not contagious, such as Helicobacter pylori and hepatitis B. (We will discuss this in detail later.)

When a family lives together for a long time, eats and drinks basically the same thing every day and lives in basically the same environment, they may be subtly influenced by the same carcinogenic factors or triggers.

For example, the father likes to eat moldy tofu, and the mother likes to eat leftovers for economical purposes. These foods are present on the dinner table for a long time, and the son and daughter are forced to accept them. Moldy and overnight food will increase the risk of liver cancer and stomach cancer.

To give another example, the father is a heavy smoker. After dinner, he likes to light a cigarette and watch TV in the living room. The whole family is forced to inhale secondhand smoke, which will definitely increase the risk of lung cancer.

Another example is the environment. Studies have shown that the environment is one of the factors that cause cancer, and air pollution is one of them. When a family lives in an environment without ventilation and where chemicals and smelters are uncontrolled and not effectively handled around them, will the chances of developing cancer increase?

In addition, we believe that emotions are contagious and can also induce cancer. When a family is not harmonious, negative emotions shroud it for a long time, and tension and anxiety continue to escalate, the family will inevitably be affected to varying degrees.

To sum up, these so-called "family cancers" will not necessarily occur, but the possibility of them is the biggest risk, and we must pay special attention and prevent them; "family cancers" are more common in the digestive tract system, and the same environment and emotions are also triggers.

3 Cancer is not contagious, but some carcinogenic viral factors are contagious.

Infectious viruses can cause continuous damage to an organ in the body, thus affecting the normal functioning of the organ. Although it does not happen overnight, if there is no intervention and treatment during the entire damage process, when the qualitative change reaches a certain extent, cancer may come to you.

Liver cancer

Infectious virus: Hepatitis B

Hepatitis B-liver cirrhosis-liver cancer is known as the "liver cancer trilogy". The hepatitis virus replicates and multiplies in the human liver, causing inflammation and necrosis of liver cells, causing continuous damage to the liver. If hepatitis B patients take it lightly, they may develop cirrhosis or even liver cancer.

Data show that the incidence of hepatitis B in my country is about 8-10%, and there are about 20 million chronic hepatitis B patients (inflammatory lesions in the liver). The Chongqing 2016 New Tumor Report shows that the incidence of liver cancer has reached 29.19/100,000.

Clinical data show that 80% of primary liver cancer patients have hepatitis B. Without intervention, nearly 1/3 of hepatitis B will turn into cirrhosis, and about 3-6% of cirrhosis patients will develop into liver cancer.

Transmission: Hepatitis B is not transmitted through sharing eating utensils, breastfeeding, hugging, kissing, shaking hands, coughing, sneezing, playing in public swimming pools or similar behaviors, but it can be transmitted through blood, mother-to-child, and unsafe sexual contact.

Prevention: Everyone should be extra careful about the use of various medical devices such as injections, vaccinations, tattoos, etc. Multiple sexual partners are not recommended, and it is best to use condoms during sexual intercourse.

It is recommended that everyone get vaccinated. This is not only the most effective, simple and economical measure to prevent hepatitis B, but also an effective way to control hepatitis D virus infection.

Gastric cancer

Infectious virus: Helicobacter pylori

Helicobacter pylori plays a very primary role in the development of gastric cancer, but this disease must be prevented because the chance of getting the disease is very high and it will also continue to damage the stomach.

After infection with Helicobacter pylori, gastric mucosal cells will undergo a series of changes: normal gastric mucosa → chronic superficial gastritis → chronic atrophic gastritis → intestinal metaplasia → dysplasia → gastric cancer. "Currently, it can be confirmed that 1% of Helicobacter pylori has a direct causal relationship with gastric cancer patients."

Transmission route: Helicobacter pylori is generally transmitted through oral transmission, close contact, eating contaminated food and drinking water, etc. Therefore, in many cases, the main source of Helicobacter pylori infection comes directly from family members. For example, if patients are used to using chopsticks and do not have a separate dining system, they will be repeatedly infected, resulting in unsatisfactory treatment results and increased treatment costs.

Prevention: If you or someone in your family is infected with Helicobacter pylori, you should receive standardized treatment under the guidance of a doctor and take precautions. It is best to separate meals from your family, or use public chopsticks and spoons to serve rice and pick up dishes. Do not pick up dishes for each other, and avoid feeding children with your mouth. Make sure to clean the bowls and chopsticks and disinfect them at high temperature.

Develop good hygiene habits, wash hands before and after meals, wash or peel vegetables, fruits, and try to cook them well, do not eat half-cooked steaks and other foods, do not drink raw or cold water, do not eat too hot food, and try to reduce eating out. In addition, the diet should be nutritious, the food should be soft and easy to digest, eat small meals frequently, chew slowly, and maintain a good attitude and a happy mood every day to avoid the occurrence of stomach diseases.

Cervical cancer

Infectious virus: HPV virus

HPV types 16 and 18 have been identified as the direct cause of cervical cancer. Under normal circumstances, HPV viruses are cleared by the human immune system, so short-term infections are normal, similar to when you have a viral cold. Even before you develop cold symptoms, the virus has been cleared from your body and will not develop into precancerous lesions.

Only a small number of women with weak immune function or defective immune mechanism are unable to eliminate HPV that enters the body, resulting in persistent HPV infection and the possibility of developing cervical cancer.

The carcinogenic process of HPV does not happen overnight, but the period of HPV infection-persistent infection-precancerous lesions-cancer is usually about 10 years.

Transmission route: The main transmission route of HPV virus is sexual contact, and there is also a chance of infection through contact with the infected person's clothing, daily necessities, etc. The prerequisite is that the cervix is ​​damaged and the virus enters the cervical epithelial cells.

Prevention: HPV vaccination is the best method, which can prevent 70% of cervical cancer. At present, bivalent and quadrivalent vaccines are available in China. Compared with the bivalent cervical cancer vaccine, the biggest difference of the quadrivalent vaccine is that it can prevent more types of HPV subtypes. The bivalent vaccine mainly prevents HPV16 and 18 viruses, which are important factors in causing cervical cancer. In addition to preventing HPV16 and 18 viruses, the quadrivalent vaccine can also prevent HPV6 and 11 subtypes, which are viruses that cause genital warts such as condyloma acuminatum.

Nasopharyngeal carcinoma

Infectious virus: Epstein-Barr virus

Epstein-Barr virus is the pathogen of infectious mononucleosis, which is closely related to the occurrence of nasopharyngeal carcinoma and childhood lymphoma. Among patients with nasopharyngeal carcinoma, more than 90% of patients have positive Epstein-Barr virus tests.

Natural infection of Epstein-Barr virus is very common in the human population, and almost everyone will be infected with Epstein-Barr virus in their lifetime. However, infection with Epstein-Barr virus does not mean that one will definitely develop nasopharyngeal cancer in the future. In most cases, Epstein-Barr virus can "coexist peacefully" with humans. Only in certain specific circumstances, such as when the immune system is deficient, Epstein-Barr virus may proliferate wildly, induce the infected epithelial cells to lyse and become cancerous, leading to the occurrence of nasopharyngeal cancer.

Transmission route: Mainly through saliva.

Prevention: Avoid close mouth-to-mouth and nose-to-nose contact, and take precautions in crowded and noisy places.

4 How do you view cancer?

The World Health Organization states that one-third of cancers are completely preventable; one-third of cancers can be cured through early detection; and one-third of cancers can be treated with existing medical measures to prolong life, reduce pain and improve quality of life.

Cancer should be considered a lifestyle disease. There is solid evidence that smoking, drinking, obesity, stress, lack of exercise, etc. are all high-risk factors for cancer. We should quit smoking and drinking, eat a healthy diet, exercise moderately, and relax. "As long as we change our unhealthy lifestyle, have regular physical examinations, and achieve the "three early" of early detection, early diagnosis, and early treatment, we can prevent cancer to the greatest extent and increase the survival rate of cancer."

We can carry out prevention and control through three levels of prevention. The first level of prevention is the prevention of the cause, reducing the damage caused by external adverse factors; the second level of prevention is early detection, early diagnosis, and early treatment; the third level of prevention is to improve the quality of life and prolong survival time.

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Chongqing Science Popularization Base/Member of China Medical We-Media Alliance

Chongqing Municipal Science and Technology Commission Science and Technology Communication and Popularization Project

National Health Commission National Basic Public Health Service Health Literacy Project