VIRTUAL HEALTH LIBRARY - ONCOLOGY

A risk factor is a factor that increases the probability of an individual suffering a disease, in this case, cancer.

There are factors that cannot be avoided called intrinsic, such as age, gender, family background. There are other factors that can be avoided or modified such as smoking, diet and sun exposure.

Cancer like many chronic diseases is rarely due to a one single cause but to several causes.

Smoking (click on the smoking link) is the number one cancer risk factor that can be prevented. The organs most directly exposed to tobacco smoke are the ones more seriously affected but distant organs such as the bladder, the cervix and pancreas are also at risk.

It should be borne in mind that smoking is a chronic disease with relapses and that tobacco is to be considered an addictive substance. The risk of disease is directly related to the number of cigarettes smoked, addiction length and type of tobacco smoked.

After 30 years of campaigns against smoking in developed countries, a decrease in smoking has been recorded amongst men. In women, however, the opposite has been the case which has led to a significant increase of smoking-related pathologies, such as lung cancer.

In Uruguay, the number of deaths by cancer caused by smoking is 2464 a year, the main cause of death being lung cancer.

The combination of alcohol consumption and smoking determines an increase in the incidence of esophagus, mouth and larynx cancer. Alcohol acts as a solvent of tobacco carcinogenic substances.

Diet is also a factor in cancer development. Excessive fat intake has been associated with the development of different tumors, particularly, breast, ovary, endometrium, colon and prostate cancers. Such correlation does not establish clear causality. A fiber-rich diet, which is linked to less frequent colon cancer is advisable. Some substances like Omega 3 present in fish and anti-oxidants are being studied as possible protecting factors.

Experimental studies in animals have shown that certain kinds of additives (cyclamate, aspartame, saccharine, preservatives and colorants) are linked to cancer, which has not yet been proved by epidemiological studies on humans.

Foodstuffs preparation, cooking and conservation forms may produce carcinogenic substances, for example, smoked products and roast beef contain flavor polycyclic hydrocarbons, many of which are carcinogenic.

Additionally, foodstuffs are contaminated by substances used in the treatment of crops or during preparation as is the case with nitrites and nitrates used as preservatives. Studies conducted in different countries have proved that exposure to high levels of such substances has led to an increase in the number of stomach and esophagus cancers.

Hot infusions such as 'mate' are linked to esophagitis and esophagus cancer due to the inflammation caused by the water temperature.

Individuals with fair skin and hair and blue eyes face a major risk of developing skin cancer due to sun exposure.

The depletion of the ozone layer has caused a UV radiation increase.

Viral agents associated with the appearance and development of cancer such as papovavirus and genital herpes have shown a causal association with cervix cancer. Papovavirus is a very frequent sexually-transmitted virus whose treatment leads to cancer prevention.

There are occupational risk factors. Individuals working in industries using anilines, paints, rubber, chimney sweepers, face greater risk of developing some kinds of cancer (bladder, testicle, etc.)

Cancer is not an inheritable disease, what is inherited is cancer predisposition. Cancer results from an accumulation of genetic changes or genetic mutations occurring in normal cells. At present, it is thought that 5% to 10% of tumors develop due to the inheritance of a cancer susceptibility gene (particularly breast and colon cancer).

ACS. Risk Factors: http://www.cancer.org/docroot/WHO/WHO_0.asp