What is Cancer?

What is Cancer?

All living things such as germs, insects, animals and human beings are made of numerous cells. Human body itself is made up of millions of cells that are specially adapted to carry out particular functions – such as the sex cells, sperms and ova, carry out the function s of reproduction.

Now, what is a cell? The cell is the basic unit of all living things or organisms, which can reproduce itself exactly. A collection or mass of cells of one kind is called tissue – such as nervous tissue, muscular tissue, connective tissue, etc. And aggregation or collection of tissues constitutes organs, such as heart, lungs, liver, etc. In other words, an organ is a part of the body, composed of more than one tissue.

As the human body grows from infancy to adulthood, the cells belonging to different tissues and organs divide and subdivide until no more increase of the cells is required except for the normal wear and tear of the body. Normally the rate at which an organ should grow and when it should stop growing, is under the control of the body itself.

Cancer arises from the abnormal and uncontrolled division of cells, know as cancer cells, that then invade and destroy the surrounding tissues. Cancer cells, in other words, refuse to stop multiplying and continue to increase in number. It is the failure to stop multiplying which is the hallmark of cancer. This they do even at the cost of other normal cells of the body which are starved to heath for lack of nutrition.

Cancer cells are different from normal cells in some aspects. They do not remain confined to one part of the body. They penetrate and infiltrate into the adjoining tissues and dislocate their function. Some of the cancer cells get detached from the main mass or site of origin and travel by blood and lymph channels to sites distant from the original tumor and form fresh colonies, called metastasis or secondary growths, in other organs where they grow at the cost of the normal cells. This is how they destroy the well-regulated functioning of the body and bring about its end.

A cancer may be slow-growing or fast-growing. The rate at which a cancer grows depends on the tissue in which it occurs and also on the inherent character of the type of cancer. Rapidly growing cancers are those which send metastasis in other organs, are much more dangerous. Sometimes the primary cancer in first stage of development grows slowly, as for example, that of the stomach and remains unnoticed, while the secondaries spread rapidly in the liver, abdominal lymph glands, etc. These secondary cancers are first noticed.

Growth of cancer cells leads, generally, to formation of a nodule or tumor. Hence, cancer is also called a tumor. If it is superficial, it is firm to touch, get fixed to surrounding tissues and is not freely moveable. Every nodule, however, is not a cancer. Some like warts, cysts, or adenomas are benign and are easily treated. But in order to be sure whether a nodule is cancerous, a bit of the nodule is taken and examine under the microscope. This generally gives a correct diagnosis.