Cancer is one of the leading causes of death worldwide. There are more than 200 types of cancer. The most common include cervical, breast, lung, prostate, skin and bowel cancers.
Cancer is a condition where cells in one part of your body grow and reproduce uncontrollably. The cancerous cells may invade and destroy surrounding tissue, including organs. They may spread to other parts of the body. The uncontrollable division and development of these cells may lead to the formation of a tumour.
Left untreated, most cancers are likely to result in death. Diagnosed early enough, many cancers can be successfully treated.
Tomorrow (February 4) is World Cancer Day, a day dedicated to raising awareness of cancer and encouraging its prevention, early detection and treatment.
Tumours can be benign, malignant (cancerous) or precancerous. Benign tumours are not cancerous. They tend to grow slowly, do not spread to other parts of the body and are usually made up of cells similar to normal or healthy cells. They only cause a problem if they grow large, become uncomfortable or press on other organs.
Malignant tumours are faster growing. They may spread and destroy neighbouring tissue. Cells of malignant tumours can break off and spread to other parts of the body through a process known as metastasis.
When they infect healthy tissue at the new site, they continue to divide and grow. These secondary sites are known as metastases. The condition is referred to as metastatic cancer.
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Precancerous or premalignant tumours are formed by abnormal cells which may or are likely to develop into cancer, if untreated.
Types of cancers
There are five main types of cancer, namely carcinoma, sarcoma, lymphoma and myeloma, leukaemia and brain and spinal cord cancer.
Carcinoma arises from the epithelial cells which are the lining of cells that helps protect or enclose organs. Carcinomas may invade the surrounding tissues and organs and metastasise to the lymph nodes and other areas of the body. The most common forms of cancer in this group are breast, prostate, lung and colon cancer.
Sarcomas begin in bone or soft tissue such as fat, muscle, blood vessels, nerves and other connective tissues that support and surround organs.
Lymphomas and myelomas begin in the cells of the immune system. Lymphoma is a cancer of the lymphatic system, which runs all through the body. Myeloma or multiple myeloma starts in the plasma cells, a type of white blood cell that produces antibodies to fight infection. This cancer can affect the cell's ability to produce antibodies effectively.
Leukaemia is a cancer of the white blood cells and bone marrow, the tissue that forms blood cells.
Brain and spinal cord cancers are known as central nervous system cancers.
As with many illnesses, most cancers are the result of exposure to a number of different causal factors.
Alcohol can increase the risk of several types of cancers, including bowel, breast, mouth, throat, oesophageal, liver and stomach cancer. The more alcoholic drinks you consume the higher the risk. Even moderate alcohol drinking increases the risk.
Excess weight increases the risk of developing different cancers, including bowel and pancreatic cancers.
Diets high in red meat, processed meats and salted foods and low in fruit and vegetables are believed to have an impact on cancer risks, particularly colorectum, nasopharynx and stomach cancers. Tobacco smoke contains at least 80 different cancer-causing substances or carcinogenic agents. When smoke is inhaled the chemicals enter the lungs, pass into the bloodstream and are transported throughout the body. Smoking or chewing tobacco not only causes lung and mouth cancer but is related to many other cancers.
Other causes of cancer include ionising radiation caused by the use of radon, x-rays, gamma rays and other forms of high-energy radiation.
Some people risk being exposed to a cancer-causing substance. Workers in the chemical dye industry have been found to have a higher incidence than normal of bladder cancer. Asbestos is a well-known workplace cause of mesothelioma cancer, which most commonly affects the covering of the lungs.
Some people are born with a genetic predisposition or inherited high risk for a specific cancer. This does not mean developing cancer is inevitable but a genetic predisposition makes the disease more likely.
Cancer becomes more prevalent with age. The longer you live, the more exposure there is to carcinogens and the more time for genetic changes or mutations to occur within your body cells.
Those with weakened immune systems have a greater risk of developing some types of cancer. This includes people with HIV or other conditions that reduce their immunity to disease, as well as people who, following an organ transplant, take drugs to suppress their immune system to prevent organ rejection.
Over a third of all cancers can be prevented by reducing your exposure to risk factors such as tobacco, obesity, physical inactivity, infections, alcohol, environmental pollution, occupational carcinogens and radiation.
Vaccination against the Hepatitis B Virus (HBV) and the Human Papilloma Virus (HPV) help protect against liver cancer and cervical cancer respectively.
To minimise the risk of cancer, do not smoke, limit alcohol consumption, protect your skin from overexposure to the sun, be active with plenty of exercise and eat a balanced and nutritious diet.
Early detection of cancer improves the chances of successful treatment outcomes. Treatment depends on the type of cancer, where it is, how advanced it is, whether it has spread and your general health.
If a cancer has not spread, surgery may remove the cancer completely. Often removing the affected prostate, breast or testicle provides a complete cure, unless the cancer has already spread from there.
Radiotherapy uses high-energy rays to reduce a tumour or destroy cancer cells as a stand-alone treatment or in combination with other cancer treatments.
Chemotherapy uses chemicals to interfere with the way cells divide so that cancer cells destroy themselves. It is generally used to treat cancer that has spread or metastasised because the medicines travel throughout the entire body.
Immunotherapy uses your body's immune system to fight the cancer tumour. It may treat the whole body by means of an agent that can shrink tumours.
Several cancers have been linked to some types of hormones, including breast and prostate cancer. Hormone therapy changes hormone production so that cancer cells stop growing or are killed completely.
- The information in this article is provided as a public service by the Cimas iGo Wellness programme, which is designed to promote good health. It is provided for general information only and should not be construed as medical advice. Readers should consult their doctor or clinic on any matter related to their health or the treatment of any health problem. — [email protected] or WhatsApp 0772 161 829 or phone 024-2773 0663