Table of Contents
What is Cancer?Cancer is actually a general term for a group of diseases (well over 100!) characterized by cells that divide over and over again, having lost the controls that normal cells have. When someone uses the term “cancer”, it is generally assumed that they are referring to malignant cells—those types of cells that continue to divide and have the potential to spread throughout the body, using the blood or lymphatic vessels. Tumor is another term often used—a tumor is an abnormal mass of cells—a tumor may be malignant (and can spread) or benign (abnormal, but it won’t spread beyond its location). There are a number of categories for cancer types. These include:
- Carcinoma—this type of cancer that arises from skin or tissues that cover organs
- Leukemia—cancers of the blood. There are red blood cell leukemias and white blood cell leukemias
- Sarcoma—cancers that arise in connective tissue such as muscle, bone, cartilage, fat or the blood vessels.
- Lymphoma—cancers of the cells of the immune system
- Myeloma—these are also immune system cancers
- Nervous system cancers
Normal cells divide and multiply in order to replace themselves. Cancer occurs when the control of this growth is disrupted. Many things cause cancer and many factors can affect whether one person or another will get cancer. Some of the things that are known to cause cancer are:
- Toxins and chemicals in food, the environment and products we use
- Infectious agents such as viruses and bacteria
- Radiation from natural and man-made sources
Other factors can increase the risk of certain types of cancer. These include:
- Behavioral risk factors—the way you behave may increase your risk. Smoking is a behavioral risk factor.
- Environmental risk factors—where you live may be a risk factor. If you live over a chemical waste site, this would increase your risk.
- Biological risk factors include your gender, ethnicity, age and skin color.
- Genetic risk factors—these are related to your family of origin and their medical history.