About Cancer
Key Facts (as published by WHO)
- Cancer is a leading cause of death worldwide: it accounted for 7.9 million deaths (around 13% of all deaths) in 2007.
- Lung, stomach, liver, colon and breast cancer cause the most cancer deaths each year.
- Tobacco use is the single most important risk factor for cancer.
- The most frequent types of cancer differ between men and women.
- About 30% of cancer deaths can be prevented.
- Cancer arises from a change in one single cell. The change may be started by external agents and inherited genetic factors.
One defining feature of cancer is the rapid creation of abnormal cells that grow beyond their usual boundaries, and which can then invade adjoining parts of the body and spread to other organs. This process is referred to as metastasis. Metastases are the major cause of death from cancer.
Common cancers
- Among men - Lung, Stomach, Liver, Colorectal, Oesophagus and Prostate
- Among women - Breast, Lung, Stomach, Colorectal and Cervical.
What causes cancer?
Cancer is the transformation of a normal cell into a tumour cell. This change is a result of the interaction between a person's genetic factors and three categories of external agents, including:
- Physical carcinogens, such as ultraviolet and ionizing radiation
- Chemical carcinogens, such as asbestos, components of tobacco smoke, aflatoxin (a food contaminant) and arsenic (a drinking water contaminant)
- Biological carcinogens, such as infections from certain viruses, bacteria or parasites.
Some examples of infections associated with certain cancers:
- Viruses: Hepatitis B and Liver Cancer, Human Papilloma Virus (HPV) and Cervical Cancer, And Human Immunodeficiency Virus (HIV) and Kaposi sarcoma.
- Bacteria: Helicobacter pylori and Gastric cancer.
- Parasites: Schistosomiasis and Bladder cancer.
Ageing is another fundamental factor for the development of cancer. The incidence of cancer rises dramatically with age, most likely due to a buildup of risks for specific cancers that increase with age. The overall risk accumulation is combined with the tendency for cellular repair mechanisms to be less effective as a person grows older.
How can the burden of cancer be reduced?
Incidences of Cancer can be reduced and controlled by implementing evidence-based strategies for cancer prevention, early detection of cancer and management of patients with cancer.
About 30% of cancer could be prevented by modifying or avoiding key risk factors.
Key risk factors for cancer:
- tobacco use
- overweight or obese
- low fruit and vegetable intake
- physical inactivity
- Consuming alcohol
- sexually transmitted infections, such as HIV and HPV
- urban air pollution
- indoor smoke from household use of solid fuels
Prevention strategies:
- increase avoidance of the risk factors listed above
- vaccinate against human papilloma virus (HPV) and hepatitis B virus (HBV) infection
- control occupational hazards
- reduce exposure to excessive sunlight
Early detection:
Cancer burden could be decreased substantially if detected and treated early. The aim is to detect the cancer when it is localized (before metastasis). There are two components of early detection efforts:
- Education to help people recognize early signs of cancer and seek prompt medical attention for symptoms, which might include: lumps, sores, persistent indigestion, persistent coughing, and bleeding from the body's orifices.
- Screening programs to identify early cancer or pre-cancer before signs are recognizable, including mammography for breast cancer, and a "pap smear" for cervical cancer.
Treatment and care:
- Treatment aims to cure, prolong life and improve quality of life for patients. Some of the most common cancer types, such as breast cancer, cervical cancer and colorectal cancer, have high cure rates when detected early and treated according to best practice. Principal treatment methods are surgery, radiotherapy and chemotherapy.