You can get HPV directly from the mouth. It doesn't need to get to the stomach. It causes papillomas to appear, which can look like tumors. Same for herpes vir

You can get HPV directly from the mouth. It doesn't need to get to the stomach. It causes papillomas to appear, which can look like tumors. Same for herpes virus. It causes ulcerations, but too common and small to be confused with cancer.