Articles

Cancer

What is it and what are the risk factors commonly associated with it?

A cancer is a group of cells that has lost its normal control mechanisms and thus has unregulated growth. As they multiply and grow they form a mass of cancerous tissue called a tumor that invades and destroys adjacent healthy tissues. The change in the cell’s genetic material may occur spontaneously or be caused by an agent that causes cancer (a carcinogen). Carcinogens include many chemicals, tobacco, viruses, radiation and sunlight and a genetic flaw in a cell may make it more susceptible. It is estimated that genes cause only about 5% of cancer deaths compared with about 30% from tobacco smoke and a further 30% from saturated fats and red meat. Infections account for a further 5%.

Cancers can behave differently in how they spread. A cancer that remains confined to its original location is termed cancer in situ, whereas those that invade surrounding tissues are called invasive and those that migrate to distant locations are called metastatic.

Societal Impact

It is estimated that about 40% of the population will face a cancer diagnosis and that of these about 20% will die of the disease. The most common types of cancer in decreasing order of frequency are prostate, breast, lung, colorectal, bladder, skin, non-Hodgkins lymphoma, uterine, ovarian, kidney and leukemia.

Symptoms

Cancer tumors are themselves painless and symptoms often result from the growth of the cancer interfering with other bodily functions. For example, a cancer growing on a vocal chord will cause hoarseness when it is quite small whereas one growing in the large intestine may cause no symptoms until it is quite large. Other symptoms may result from the production of toxic substances or from the use of energy and nutrients normally available for other functions. Also, cancer can cause one set of symptoms as it grows initially and quite different symptoms as it spreads to other tissues or other parts of the body.

Some typical symptoms include discomfort turning to pain, bleeding, weight loss and fatigue, swollen lymph nodes, depression, neurologic and muscular sensations and respiratory symptoms.

Diagnosis and Treatment

Because the probability of successfully treating a cancer is much higher if the cancer can be diagnosed early, a variety of screening tests are used for each type of cancer. If there is reason to believe that cancer may be present several diagnostic tools are available including biopsies, scans, x-rays, ultrasound and blood tests to identify tumor markers.

Cancer is usually treated in one, or more, of four ways, surgery, radiation, chemotherapy and immunotherapy. If the cancer is accessible, and has not spread, surgery may be successful. Radiation is used to kill cancer cells but will also injure some surrounding tissue, which may be able to recover when the cancerous cells are killed. Chemotherapy uses chemicals circulated in the blood to kill tumor cells. Its advantage is that it reaches all parts of the body but it also can kill a large number of healthy cells causing patients to feel very sick. Sometimes all three treatments are used in combination. Immunotherapy uses the body’s immune system to attack the cancer cells. Other new genetic and biologic treatments are also being developed and some people have been successful with alternative medicines in treating cancer but these are not generally scientifically proven and can interact with the standard treatments.

Complications

A cancer diagnosis can have dramatic psycho-emotional effects, which require supportive and careful handling. People cope in different ways but, feelings of isolation are one of the biggest problems and maintenance of family social contacts becomes very important. Organizations like Gilda’s Club can help in these areas.