Disease Focus: Cancer

Overview, most common types

Perhaps one of the first things we think of a when we hear the word "disease" is cancer. Almost everyone knows someone whose been diagnosed with it. Cancer can be present anywhere in the human body. It occurs when new cells are formed, but old ones are not dying. These excess cells can create masses called tumors. Cancerous tumors are considered malignant, which means that their cells can also invade nearby tissue, and spread the cancer. Some of the most common forms of cancer are breast cancer, lung cancer, skin cancer.

Breast cancer is most often found in women, but it can also occur in men. It is the second leading cause of cancer death in women. The majority of the time, the cancer begins in the ducts that carry milk to the nipples. There are also other types of breast cancers, but they are far less common. Most breast cancers also produce a tumor, or a lump, in the breast, yet not all of them do. While most breast cancers cause these lumps, most lumps in breasts are benign, but it is still always important to have any lumps checked out by a doctor.

There are three different types of lung cancers. Non-small cell lung cancer, small cell lung cancer, and a lung carcinoid tumor. The most common of these is non-small cell lung cancer, so that is the type I will discuss. This type is responsible for 80-85% of lung cancers. It can be found in many parts of the lungs including the cells that normally secrete mucus, bronchi, and airways. Lung cancer is most commonly found in current or former smokers.

One of the most dangerous types of skin cancer is melanoma skin cancer. It begins in the melanocytes, a layer of the skin responsible for pigment. Melanomas are most likely to form on the chest or back in men, and on the legs of women. However, they can form anywhere on the body. While melanoma is less common than other types of skin cancer, it is more dangerous because it is more likely to spread to other parts of the body, especially if it is not caught early. Some of the most common causes of this cancer are exposure to ultraviolet light, moles, fair skin, and a weakened immune system.



http://www.cancer.org/cancer/