Infectious diseases
Impressively enough, there are certain infections that make us more likely to develop cancer. For example, Helicobacter pylori infections in the stomach will not only cause severe gastritis and gastric ulcers but also stomach cancer. Papillomavirus infections in a woman’s cervix is a cause of cervical cancer. Both microorganisms affect the DNA of cells either directly or indirectly and predispose to the formation of tumors.