|MadSci Network: Medicine|
Thanks for your question, Taylor.
Cancer, like the common cold, is actually a whole bunch of different diseases that are all called cancer, even though they're all individually very different. Each kind of cancer has its own causes, and the causes are very different from one another. The National Cancer Institute has a webpage that talks about the different causes.
The National Cancer Institute calls the causes "risk factors", which means that each cause they list might not cause cancer by itself, but could cause cancer in combination with other risk factors.
One thing that happens when people get cancer is that certain specific cells that make up your body forget to stop growing. Smoking cigarettes or not wearing sunscreen are two "risk factors" that can sometimes cause certain cells in your body to forget to stop growing, but sometimes you can actually inherit risk factors from your parents.
Having a risk factor doesn't mean you will get cancer. It just means that you have to be more careful to not get any more risk factors. The good thing is that risk factors are very rare. There are no foods that cause cancer (or cure it), and even most chemicals don't cause cancer. Also, you can't catch cancer from someone who has it.
Try the links in the MadSci Library for more information on Medicine.