Cancer is a major world health problem with approximately 10 million new cases occurring each year. With 7 million cancer-related deaths per year, this condition has a very high mortality rate. The most common kind of cancer is skin cancer, but malignancies of the gastrointestinal tract, lungs, and skin are also common. 30% of all cancers, especially lung, bladder, kidney, and nasopharyngeal cancers, are attributed to tobacco smoking. A further 30% of cancers are attributed to alcohol and diet.
Cancer occurs when the cells of the body start dividing uncontrollably and override the body’s commands to stop cell division. With time, cancer spreads – metastasizes – to other parts of the body. Metastasis is the principal cause of morbidity. Although the aim of cancer treatment is usually palliative, a complete cure is also possible. Cancer is usually treated using surgery (in early stages), radiation therapy, and chemotherapy.