According to the World Health Organisation, Cancer remains the second leading cause of death globally. Fourteen million new cases were reported globally in 2012, while 8.2 million people died of cancer globally in the same year.
In 2015, it caused about 8.8 million deaths globally, one in every six deaths.
Cancer can affect any organ or part of the body but the most common cancers in men are that of lung, prostate, colorectal, stomach and liver cancer. In women the most common cancers are that of breast, colorectal, lung, cervix and stomach.
The yearly figure of new cases is expected to use to about 22 million in the next twenty (20) years.
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 (75) percent of long and laryngeal cancer are due to tobacco while sixty six (66) percent are due to tobacco chewing. Research claims active smokers have twenty (20) times more risk than men smokers, passive smokers (those who do not smoke but breathe in the smoke) have about of two (2) times more risk than non-smokers.
The effect of smoking is related to donation of smoking, number of sticks a day and amount of smoke taken in.
There is an association between alcohol and some cancers. These cancers include – cancer of the mouth, of the throat, liver and breast. The risk is about five (5) to ten (10) times higher in heavy dunkers 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 cancer 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 include – asbestos, benzene, soots, silica, arsenic, nickel, and coal tars.
4. Environmental Pollution
Our physical environment – air, water and soil – can increase our brisk of developing cancer of contaminated. Pollution of the air by chemicals (fames, smoke) if inhaled increases the risk of lung cancer, those living near refineries, incinerators are specially at risk of cancer of the bladder, skin and lungs. Soil, contaminated by pesticides affects the food chain – taken up by plants which are later eaten by man, is also incriminated in some cancers.
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 by about 25 and 67%. Obesity is also linked to some cancers. Vitamins and minerals are also said to be protective against cancer of the prostate, colon and rectum.
6. Food Contaminants.
As said earlier, contaminated soil can affect the food chain, plants 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. DDT is associated with cancer of the pancreas, breast and lymph nodes.
Processing of food, frying of meat and preserving of food can give rise to some products which can cause cancer.
During storage; certain foods such as corn, groundnut and dry fish can be contaminated by some yeast like fungi which contain aflatoxins which can cause cancer.