The plethora of causes alleged for cancer only point to the fact that we do not yet have a true and correct knowledge of this disease. The success of a military operation without a true and authentic knowledge of the martial prepares of the enemy can just be guessed.
    The main causes of defeat are that cancer is an enemy of mankind more powerful than any other disease. The external bodies (bacteria or virus) that cause Typhoid, Pneumonia, or smallpox are like enemy troops who intrude from outside alien to the human immune system. These can be driven back or destroyed. But in the case of cancer, a subtly transformed patient's own cell which evictees to a greater or lesser degree immunologically from a normal cell and may, therefore, evade the normal immune surveillance mechanism. It is the cells of one's own body that turn inimical and declare war against them.

    Reports of heroic success in cancer treatment are galore in our periodicals. But researches into this disease give only little hope to us. If we try a very close look at this problem, it can be seen that the nature of the disease is different in different countries. The environment an individual lives in, his habit and life style, the food-health and other customs of his society, the presence of different chemicals and other materials in the place where he works, his vulnerability to viral attacks, and a lot of such other factors can cause cancer, it is proved. From ten to twenty years of consuming a particular food or possessing a particular habit may be required to produce the primary symptoms of the disease. Therefore it is not that much easy to find out which food or which habit is harmful. It is also difficult to find out the causes of cancer in human beings by conducting experiments on animals. A drug, which acts in one way on one species, acts differently on other. Morphine, for example, depresses the central nervous system in human beings but stimulates it in cats and horses.
    It is an approved fact that smoking raises the possibility of contracting cancer ten times more. But the relation between smoking and cancer could not be established through experiments till now because experiments could be done only on animals and animals are not smokers. The connection between smoking and cancer cannot be scientifically approved just because cancer is seen among smokers more than in non-smokers. The smoke exhaled by a smoker contains ten times more Nitrosamines than which does he inhales. Nitrosamine is the chemical contained in cigarette smoke that causes cancer. So it is evident that passive smoking are more affected by nitrosamine than smokers. Mouth and throat cancer is seen more in India than in other countries. In the cause of stomach cancer Japan and Germany are in the forefront. While in America more women are affected by breast cancer Indian women are more affected by cancer of the uterus.
    The things that can cause cancer are known as Carcinogens. The period from the time of the first contact with these things to the time of showing the first symptoms is known as latency period. The latency period can extend from five to forty years. There fore we cannot rule out cancer if it does not appear a few years after the first contact with he carcinogen. On the other hand even a brief contact with the carcinogen can produce cancer even a long period after wards. To make it more explicit, a co-carcinogen is required to produce cancer in the cells.
    The co-carcinogen acts on the pre-malignant cells. Very little quantity of a poisonous chemical will be enough to turn the cells pre-malignant. The pre-malignant state of the cells continues as such, until a co-carcinogen appears. The carcinogen turns the pre-malignant cells cancerous.
It was Sir Percival Pott who first discovered that chemicals could cause Cancer. It was also discovered in 1755 AD that Polycyclid Hydrocarbons Present in Coal tar, Aromatic dyes, Asbestos and the like are carcinogens. This fact has universal approbation today. The sad fact with these Compounds is that long before these were found dangerous, they were being Used as preservatives of food and for artificial coloring of Confectionery. Among these B. V. O. is a very dangerous material, Comparatively a new comer in the family, which has been widely used as a Preservative in cold drinks.