Overview of cancer

There are more than 100 diseases that are covered under the umbrella of cancer. The common denominator of all is an abnormal division of cells - malignant cells are those that grow without control. It is known that cell division is an important process of the body that allows to grow and repair the damage caused, when the DNA that controls the division of the cells fails, the cancer enters the scene. These cancer cells invade others and healthy tissues, something that healthy cells do not.

Causes

Damage to DNA cells causes DNA to replicate rather than die when it is not necessary, thereby creating more cells that contain damaged DNA. There are many causes for this damage, from genetic malformations to environmental causes such as smoking or exposure to asbestos.

However, the cause is not always known. If the cancer cells spread to other parts of the body such as blood or lymph nodes, it is said that there is metastasis. This is usually a sign that the cancer is in its last stages, which makes the disease more difficult to treat.

Although commonly referred to as tumor and cancer, these words refer to two different things: not all cancers cause a tumor or all tumors are cancerous. Leukemia, for example, causes cancer cells to pass into the blood and into the organs that secrete it like the marrow but it does not form a tumor. Benign tumors are not carcinogenic and do not invade other tissues. However a benign tumor can cause health problems if it grows and presses other organs interfering with the function of these.

Types of cancer

Cancer can be divided into different categories according to the location where they originate. Carcinomas are cancers that start in the skin or on the membrane of internal organs, while sarcomas are those that start in the bones, cartilage, blood, large intestine, and other connected tissues. Leukemia, as we said before, begins in the tissues that make blood and lymphoma and myeloma are cancers of the tissues and organs of the immune system. Finally, cancers of the central nervous system are those that develop in the brain and spinal cord.

Unfortunately, cancer has become an extremely common phenomenon. The American Cancer Society predicts that one third of women and half of men in the United States will develop cancer at a time in their lives. According to the National Cancer Institute more than 1.5 million cancers, not including melanoma, were diagnosed in 2010 and 569,490 people died of cancer. Risk factors vary from region to region as well as from person to person. Known risk factors include smoking, excessive drinking, being exposed to ultraviolet rays and the sun's rays and a poor diet.