On Tuesday, the 4th of February 2014, a day observed globally as World Cancer Day, the World Health Organisation declared cancer the World’s biggest killer.
Fourteen(14) Million cancer cases were reported globally in 2012, while 8.2 million people died of cancer globally in the same year. The yearly figure of new cases is expected to increase to about 22 million in the next twenty (20) years.
The commonest cancers reported in 2012 are:- Lung cancer, breast cancer, large intestine cancer, prostate cancer, liver cancer, cancer of the cervix and Non-Hodgkin Lymphomas (NHL). Some of the causes of cancer are discussed below:
Cigarette, cigar and pipe smoking increase the risk of lung, laryngeal and mouth cancers. Seventy five percent (75%) of lung and laryngeal cancers are due to tobacco while about sixty six percent (66%) are due to tobacco chewing.
Research claims active smokers have twenty (20) times more risk than non-smokers, passive smokers (those who do not smoke but breathe in the smoke) have about two (2) times more risk than non-smokers.
The effect of smoking is related to a duration of smoking, number of sticks smoked a day and amount of smoke taken in.
There is an association between – alcohol and some cancers. These cancers include – cancer of the mouth, throat, liver and breast. The risk is about five (5) to ten (10) times higher in heavy drinkers than in those who do not take alcohol.
Alcohol is said to contain something that increases the risk of cancer particularly that of the mouth and throat.
3. Occupational Exposures:
The type of work done by persons is very important in certain types of cancers, such as cancer of the lung, the scrotum, skin, nose and bladder. This is due to exposure to some chemicals at place of work; the incriminated chemicals/ items include – asbestos, benzene, soots, silica, arsenic, nickel, and wall tars.
4. Environmental Pollution:
Our physical environment – air, water and soil – can increase our risk of developing cancer if contaminated.
Air polluted by chemicals (fumes, smoke) if inhaled increases the risk of lung cancer, consequently those living near refineries, incinerators are specially at risk even appropriate safety measures are not in place. Drinking water heavily contaminated by arsenic increases the risk of cancer of the bladder, skin and lungs.
Soil, contaminated by pesticides, affects the food chain and thus also incriminated in some cancers; chemicals in the soil are taken up by plants which are later eaten by man.
Diet is said to account for about 20% of cancers in the developing world. Regular and adequate consumption of fruits and vegetables gives some protection against cancer of the throat, lungs, stomach, cervix, colon and rectum.
Salt intake is said to have relationship with cancer of the stomach. Meat with cancer of the colon and rectum.
Obesity is also linked to some cancers.
Vitamins and minerals are also said to be protective against cancer of the prostrate, colon and rectum.
6. Food Contaminants:
As said earlier, contaminated soil can affect the food chain, plant take up these contaminants, these plants when consumed by man, pass on the contaminants.
Chemicals that can contaminate the soil include pesticides, such as DDT. The latter is associated with cancer of the pancreas, breast and lymph nodes.
Processing of food, frying of meat and preservation of food can give rise to some products which can cause cancer.
During storage,certain foods such as corn, groundnuts, dry fish can be contaminated by some yeast like agents which contain aflatoxins which can cause cancer