Thursday, June 27, 2013

What is Cancer?

Cancer is a term used for diseases in which abnormal cells divide without control and are able to attack other tissues. Cancer cells can reach to other parts of the body through the blood and lymph systems.
Cancer is not just one disease but many diseases and there are more than 100 types of cancer have been found. Most cancers carry the name of organs or types of cell in which they start. For example the cancer that begins in the breast is called breast cancer and that a cancer in the skin melanocytes is called melanoma.  

The cancer types can be brought under a group. The main types of cancer include:

  • Carcinoma.- Cancer that begins in the skin or tissues that line or cover internal organs. There are many sub types of carcinoma that include adenocarcinoma, basal cell carcinoma, squamous cell carcinoma and transitional cell carcinoma.
  • Sarcoma. - It is a type of cancer that starts in bone, cartilage, fat, muscle, blood vessels, or other connective or other supporting tissues.
  • Leukemia- It is a type of cancer that starts in blood forming tissue such as bone marrow and grounds for large numbers of abnormal blood cells to be produced and enter the blood.
  • Lymphoma and myeloma-It is a type of cancer that begins in the cells of the resistance system.
  • Central nervous system cancers- it is a type of cancer that begins in the tissues of the brain and spinal cord.
There are many types of cancers and for more see the list of cancers in A to z List of Cancers and List of Cancers by Body Location/System.

Origins of Cancer

All cancers start from cells the body’s basic unit of life. To understand the cancer it is helpful if you know what happens when normal cells become cancer cells.

The human body is made of many different types of cells. These cells grow and separate in a controlled manner to manufacture more cells since it will help in keeping the body in good condition. When the cells become older or damaged, they die or and are replaced with new cells. However sometimes this process goes wrong. The cells did not die and when they should and new cells that forms in the body does not require them and the extra cells may form a tissue called a tumor. The tumor is classified into two one is Benign tumors and Malignant tumors. Not all tumors cause cancer.