What is cancer?
- Sometimes, cells multiply in a person’s body in ways that are not expected and may not be helpful.
- If the abnormal cells form solid growths, they are called tumors.
- Tumors can be either benign (not known to spread widely in the body) or malignant (can spread widely).
- When a tumor is malignant, that's when we call it a cancer.
We used to think that anything called a cancer was very likely to result in someone’s death. We now know that it is not that simple. Some cancers grow, and some do not. Certain types of thyroid cancer and prostate cancer are two examples of cancers that often develop but then stop growing, never causing a problem for the person who has them.