Hi everybody,
According to my knowledge there are multiple causes of cancer. It is a very complicated process but can be simplified to lifestyle choices, chronic inflammation, infections, and genes. Here I discuss some reason:

1 - Tobacco use is the most common preventable cause of cancers. It is associated with many cancers including mouth cancer, head and neck cancer, esophageal cancer, stomach cancer, and lung cancer among others.

2 - Another cause of cancer is chronic inflammation. Some examples of chronic inflammatory conditions that lead to cancer include ulcerative colitis, Crohn's disease, and Barrett's esophagus.

3 - Genes are the blueprint to the body. There are 20,500 protein encoding genes (exons) in the human genome (Human Genome Project) and many more non-encoding sections (introns). There are 2-3 meters DNA/cell, 2 X 1013 meters per human body. There are two major types of cancer genes, tumor suppressor and oncogenes.

If you have any more Ideas and tips then feel free to share here.

Thanks
DNA Methyl transferase 3B