CANCER will become world number one killer by 2010, as the number of people in poorer countries is expected to grow due to smoking, high-fat diets and other factors, according to a report released by World Health Organisation.
Many people tend to think of cancer as one disease. But the word cancer describes a large group of diseases that have certain traits in common, yet exhibit distinctive characteristics. In fact, there are over 200 known types of cancer that all behave in different ways, grow at different rates, and respond to different types of treatment. But what all cancers have in common is the growth of abnormal cells in the body. They replicate rapidly, are difficult to destroy, and can overwhelm normal, healthy cells.
CANCER remains the main cause of death in men and women.
Medical professionals measure cancer by its stage, which is based on an assessment of the size of the primary tumor, whether it has spread, and, if so, how far. Because an accurate diagnosis is so important to effective treatment, they might use physical exams, imaging, lab tests, a biopsy, an analysis of your body’s fluids, and surgery in various combinations in the staging proce ss.
Types of cancer
There are five major types of cancer, based on the type of tissue where the diseased cells originate:
Carcinomas are solid tumors that can form on almost any organ, including the skin. Adenocarcinomas start in the cells covering a gland, such as the ovaries, and squamous cell carcinomas form in the cells covering other internal tissues, such as the cervix or lungs. 80% of tumors are classified as carcinomas.
Sarcomas start in connective tissue such as muscle, fat, cartilage, and bone. Tumors in fatty tissue are called liposarcomas, and bone tumors are called osteosarcomas.
Leukemias are hematologic, or blood, cancers that originate in the blood or blood-forming organs. These cancer cells don’t usually form solid tumors.
Lymphomas are hematologic cancers that develop in the lymphatic system — the network of nodes and vessels that transports lymphatic fluid through the body.
Myelomas, cancers that start in plasma cells found in bone marrow, were once considered uncommon but are now diagnosed much more often.
Since most parts of the body are composed of different kinds of tissue, it’s possible for two people with tumors of the same primary site to have different types of cancer. Uterine cancers, for example, are usually carcinomas, but they can also occur as sarcomas, if they develop in the connective tissue of the uterus.
Major defensive players
The immune system plays a major role in helping your body fight cancer. Here are some of the forces on the front line:
- The lymphatic system which includes lymphatic vessels, lymph nodes, and the spleen, helps the body to cleanse itself of bacteria and other harmful substances.
- Leukocytes, or white blood cells, protect the body by repairing damaged cells, killing foreign organisms, and helping heal injured tissue.
- Protein molecules called antibodies are created when the immune system detects an antigen — a bacteria, virus, or other invader. Each antibody is uniquely designed to destroy a specific antigen.
- Natural Killer, or NK, cells patrol the body, looking for cancerous cells and viruses. Unlike antibodies, NK cells carry about 100 poisonous chemical substances and can destroy intruders quickly, without ever having seen them before.
