Cluin, where did you get that? Everyone swallows trace amounts of saliva several times a day most people are not even aware they are doing it, otherwise you would choke. Not only that but you have to swallow saliva when you eat or drink. Your saliva (along with chewing)is the first step to digestion. I am pretty sure that saliva is no match for the acid in your stomach that begins the next chemical step of digestion. I never heard that in nursing school, the only ting I remember about any link to saliva and cancer was that saliva may be used to detect oral cancer and that RNA from saliva ofter show biomarkers for head and neck cancer.