Tumors cannot be transmitted through saliva, because so far no substance or factor has been found that can be transmitted through saliva or other means to cause the same cancer in other people. Therefore, eating, sleeping, being in close contact or even kissing with a person who has a tumor will not cause cancer, but it is important to note that some viruses that can cause cancer can be transmitted through saliva. Although it is not necessary to get cancer 100% of the time after contracting the virus, the chance of getting cancer is obviously increased, for example, hepatitis B virus infection is closely related to liver cancer, and hepatitis B virus can be transmitted through saliva, but not all patients infected with hepatitis B virus will get liver cancer. ebV virus may lead to nasopharyngeal carcinoma, and the virus can be transmitted through saliva and other bodily fluids, but not all patients infected with ebV virus will get nasopharyngeal carcinoma. In short, tumors do not follow the same pattern as infectious diseases. In conclusion, tumors are not transmitted from one person to another through saliva in the same way that infectious diseases are, but certain cancer-causing agents can be transmitted through saliva. However, certain cancer-causing factors can be transmitted through saliva, although these cancer-causing factors may not necessarily lead to the development of the disease in another person.