People who have lived together for a long time have the same eating habits and similar lifestyles, leading to many infections regarding diseases. So is cancer also contagious. Many cancer patients and their family members lack proper understanding of cancer and are afraid of being infected with cancer. In fact, cancer is not contagious, but it may be related to infectious diseases and living habits in the process of cancer occurrence and development, we can say that these cancers are caused by infectious diseases, but we cannot say that cancer is contagious. These three types of cancers should be beware of I. Cervical cancer The bane of cervical cancer and its precancerous lesions has been proven to be human papilloma virus (HPV) infection. HPV is mainly transmitted through sexual contact, so using condoms, limiting the number of sexual partners, postponing the time of first sex and the age of first birth can help prevent it. Women should be screened regularly for cervical screening after they pass the age of 30. Experience in developed countries has shown that cervical cancer mortality can be significantly reduced by 50% with cervical screening. What is even more gratifying is that HPV vaccine, the first cancer vaccine in human history, to prevent cervical cancer has also been developed and marketed. Our HPV vaccine has entered phase III clinical trials and the results will be available in about one and a half years. In 1994, the World Health Organization/International Agency for Research on Cancer (WHO/IARC) designated Helicobacter pylori as a class I carcinogen. H. pylori is highly contagious and can be transmitted through hands, unclean food, unclean utensils, and feces, so it is important to practice good hygiene in your daily diet to prevent infection. It is recommended that communal chopsticks and spoons be used as much as possible when dining together, and it is best to implement a meal-sharing system. Pickled foods containing nitrosamines also have carcinogenic effects, and with the role of positive H. pylori, it will increase the chance of cancer. Viral hepatitis is an important cause of liver cancer. According to the survey, there are 12 million cases of chronic hepatitis patients in China, and about 300,000 cases die of liver disease every year, 50% of which are primary hepatocellular carcinoma, most of which are related to hepatitis B and C virus infection. Viral hepatitis is divided into five main types, namely types A, B, C, D and E. In recent years, two new types of hepatitis have been reported. In recent years, two new “hepatitis viruses” have been reported, namely hepatitis G virus (HGV) and transfusion-transmitted virus (TTV), but their pathogenicity has not been confirmed. Among the five known types of hepatitis viruses, there are two main categories according to the route of transmission: one is mainly transmitted through the gastrointestinal route, such as types A and E; the other is mainly transmitted through blood, such as types B, C and D. However, viral hepatitis can be prevented, and a live attenuated hepatitis A vaccine has been successfully developed in China and has been widely used in the prevention of hepatitis A with good results. Hepatitis B vaccine was introduced in 1982, and after promoting the application of the vaccine, it has proved to be safe and effective, and has played an important role in the prevention of hepatitis B in China, especially in interrupting mother-to-child transmission.