Cancer is an umbrella term for more than 100 conditions characterized by unscheduled and uncontrolled growth of abnormal cells in the body. Since there are so many different types of cancers, healthcare experts have developed a classification system to categorize them into different types.
Cancer Classification System
Cancers are primarily classified in two ways:
1. By Site of Origin
A classification system most often used by the general public divides cancer into different types according to its primary site of development. Lung cancer, breast cancer, liver cancer, and oral cancer are all examples of cancer classification by their site of origin.
2. By the Tissue Type
This is the international standard of cancer classification used by medical experts to gain a better perspective of the nature of cancer. Cancer can be classified into six categories based on tissue type or histology (as professionals call it). These include:
I. Carcinoma
Carcinoma is the name given to cancers that originate in the epithelial cells. These could be in the internal linings of organs within the body or the epithelial cells that line the external body parts. Since epithelial cells are the most abundantly found in the body, both inside and outside, carcinomas make the most common type of cancer. According to research, about 80% to 90% of all cancers are carcinomas. Breast cancer, prostate cancer, and lung cancer are all examples of carcinomas.
II. Sarcoma
Cancers of bones, muscles, fat, cartilage, and connective tissues are called sarcomas. Depending on their exact origin, sarcomas can further be divided into multiple subcategories, such as liposarcoma (adipose tissue cancer), osteosarcoma (bone cancer), and angiosarcoma (cancer of the blood vessels).
III. Leukemia
Leukemia is a cancer of the blood cells. It initiates within the tissues where blood cells are formed, such as the bone marrow, and most commonly affects the white blood cells. However, it can sometimes develop in other types of blood cells, too.
Leukemias are commonly referred to as blood cancers.
IV. Myeloma
Myeloma is also a type of blood cancer that develops in the plasma cells of bone marrow that are responsible for producing some of the blood proteins.
V. Lymphoma
Lymphoma is also a type of blood cancer. The root cause of lymphoma is the same as that of leukemia, but as opposed to affecting your bone marrow and the blood, lymphoma affects the lymphatic system, primarily lymph tissues and nodes.
VI. Mixed Types
These are cancers that affect more than one type of cell or tissue. While they can develop at any age, mixed tumors are more common in the 40s through 60s. They are slightly more prevalent in males than females.
Why is Cancer Classification Important?
Cancer classification is critical for developing an effective treatment plan, especially by tissue type. Unless a doctor knows what type of cancer a patient has, they cannot treat it; it’s as simple as that.
Once the type of cancer is known, doctors conduct additional testing to determine how far it has progressed before beginning the treatment.