Overview of Cancer
Cancer is a condition in which cells in the body mutate and multiply abnormally. This abnormal cellular proliferation and mutation can invade local tissues and spread to other parts of the body (metastasis).
There are many different kinds of cancer, and oncology researchers and physicians have classified and differentiated them according to tissue and organ type. Any part of the body may be affected, although certain types of cancer (e.g., breast cancer, prostate cancer) are more common than others.
Many different agents contribute to the development of cancer. These agents include
- genetic factors,
- chemical and environmental exposure,
- immune disorders, and
- tissue irritation.
While most cancers eventually result in a mass that may or may not be detectable through palpation, symptoms vary widely and may not manifest until the cancer has advanced. Regular medical check-ups and the use of screening procedures recommended by a physician are important in the timely diagnosis and treatment of cancer.
With advances in medical options and an emphasis on early detection, cancer is much more readily treated than in previous decades. There are three main treatment modalities: radiation (involves irradiating the cancerous tissue), resection (involves removing the cancerous tumor), and chemotherapy (involves the use of systemic chemicals to kill the cancer cells). Other therapies, such as immunological approaches, often are used as well. It is common for more than one treatment modality to be employed at the same time, depending on the type of tumor, its location, and information from research and clinical trials.