Cancer is a term used for diseases in which a group of cells display the characteristics of uncontrolled growth, that is growth and division beyond their normal limits, invades other cells and destroys them, and sometimes spread to other locations in the body. These three malignant properties of cancers and differentiate them from normal tumors, which are self-limited and do not invade or spread to other parts of the body.

Cancer may affect people at all ages, even fetuses, but risk for the more common varieties tends to increase with age. Cancer causes about 13% of all deaths. According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007.

Cancer is usually classified according to the tissue from which the cancerous cells originate, the primary tumor, as well as the normal cell type they most resemble. These are location and histology, respectively. There are a few types of cancer that are commonly seen in humans, these include, prostate cancer, lung cancer, breast cancer, skin cancer, pancreatic cancer, testicular cancer, cervical cancer and leukemia or better known as blood cancer.

Even through the glitz and glamour of stardom many high profile people were diagnosed with cancer recently and one of the most prominent was Lance Armstrong. He was diagnosed with testicular cancer even before he won the Tour de France. The first lady of the United States, Laura Bush was diagnosed with melanoma also known as skin cancer, and is now fighting the disease. Iconic musician Bob Marley even died of skin cancer at quiet an early age. Famous cartoonist Walt Disney died of lung cancer in 1966. Even though this person have contributed to the world in various ways and has touched and changed the lives of millions, they were merely human beings. Cancer can affect anybody at anytime so it is necessary to be cautious and stay clear of the factors which influence cancer. And even though cancer is an extremely dangerous disease but with the proper treatment done at the proper time, even cancer can be cured.

Cancer can be treated by surgery, chemotherapy, radiation therapy, immunotherapy, monoclonal antibody therapy or other methods. The choice of therapy depends upon the location and grade of the tumor and the stage of the disease, as well as the general state of the patient. Removal of the cancerous cells without damaging the rest of the body is the goal of the surgical procedure that follows the diagnosis of the cancer. But since cancer has a tendency to spread throughout the body, surgery's effectiveness is limited. Radiation therapy and chemotherapy after surgery ensures. Chemotherapy is most effective in this case to eliminate cancerous cells from the body but is limited by the toxicity to the other tissues of the body. Radiation to the cancerous parts of the body is the most effective way to treat cancer but it still causes damages to the surrounding healthy tissue. Cancer treatment has come a long way and with proper research future treatments are going to be more efficient and more effective.