What is Cancer?

What is cancer?

Cancer is a class of diseases in which abnormal cells divide uncontrollably and are able to invade other tissues. There are over 100 different type of cancer and each is classified by the name of organ or type of cell that is initially affected.

(Lanchastria,2011)

Type of cancer

The few main categories of cancer include:

·         Carcinoma - cancer that begins with cells that cover external parts of body for example skin or in tissues that line internal organs. Example: lung cancer, breast cancer and colon cancer.

·         Sarcoma - cancer that begins with cells in bone, cartilage, blood vessels, fat, muscle or other connective and supportive tissue.

·         Leukemia - cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and accumulate in the bloodstream.

·         Lymphoma and myeloma - cancers that begin in lymph nodes and the cells of the immune system tissues.

·         Central nervous system cancers - cancers that begin in the tissues of the brain and spinal cord.

·         Adenomas- cancers that arise in the glandular tissues like thyroid, the pituitary gland, the adrenal gland.

(Herbal Cancer Cure,2010)

Origins of Cancer

All cancers begin in cells which is the body's basic unit of life. 

The body is made up of many types of cells. These cells grow and divide in a controlled way to produce more cells. When cells become old or damaged, they die and are replaced with new cells.

However, sometimes this orderly process goes wrong. The genetic material (DNA) of a cell can become damaged or changed, producing mutations that affect normal cell growth and division. When this happens, cells do not die when they should and new cells form when the body does not need them. The extra cells may form a mass of tissue called a tumor. Not all tumors are cancerous; tumors can be benign or malignant.

·         Benign tumors aren't cancerous. They can often be removed, and, in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body.

·         Malignant tumors are cancerous. Cells in these tumors can invade nearby tissues and spread to other parts of the body. The spread of cancer from one part of the body to another is called metastasis.

Some cancers do not form tumors. For example, leukemia is a cancer of the bone marrow and blood.

How cancer spreads

The cancer cells within malignant tumors have the ability to invade neighboring tissues and organs, thus spreading the disease. Cancer cells often break free from the tumor site and travel to the other parts of body via bloodstream or lymph vessels and begin to grow and form new tumors that replace normal tissues. This process of spreading cancer cells is called metastasis.

When cancer has metastasized and has affected other areas of the body, the disease is still referred to the organ of origination. Although most cancers develop and spread via an organ, but blood cancer like leukemia do not. They affect the blood and the organs that form blood and then invade nearby tissues.

Cancer Symptoms

Cancer symptoms are quite varied and depend on where the cancer is located, where it has spread, and how big the tumor is. . As cancer progresses to an advanced stage, common symptoms can include weight loss, fever, and fatigue. These are very non-specific symptoms that are more likely related to other less serious illnesses than cancer. 

How is cancer treated?

Cancer treatment depends on the type of cancer, the stage of the cancer (how much it has spread), age, health status, and additional personal characteristics. There is no single treatment for cancer, and patients often receive a combination of therapies and palliative care. Treatments usually fall into one of the following categories: surgery, radiation, chemotherapy, immunotherapy, hormone therapy, or gene therapy.

How common is cancer?

Today, millions of people are living with cancer or have had cancer. In Malaysia, cancer is now the fourth leading cause of death among medically certified death. Among the cancer, lung cancer is the most common killer. It is estimated that the annual incidence of cancer is 30000. The risk of developing most types of cancer can be reduced by improving the quality of life of cancer, for example, by quitting smoking, limiting time in the sun, being physically active, and eating a better diet. The sooner a cancer is found and treated, the better the chances are for living for many years.

(Sarawak Hospice Society,2009)