Definition Carcinoma in situ describes a cancer in the very earliest stage. At this point, the cancer is quite small and has not invaded the tissues around it.
What is going on in the body? Cancer develops in several stages. A cancer begins when a single cell becomes cancerous. This happens when the central control of the cell is damaged. The cell begins to grow and multiply out of control. When enough of these cells are produced they form a tumour. The tumour will eventually grow large enough to press on the tissue around it. The tumour will also invade and destroy the tissue around it. When a tumour has formed but has not begun to invade tissue, it is said to be "in situ," or in place. Some cancers may stay in this stage for a long time. Most cancers, however, do not stay in situ for long and begin to spread. Cancers found in situ are the easiest to cure because they have not spread.
What are the causes and risks of the disease? The risks for developing a particular type of carcinoma in situ (cervix, breast, and others) are the same as risk factors for developing that type of cancer.
What can be done to prevent the disease? Some cancers cannot be prevented. Other cancers, such as bladder cancer, lung cancer and throat cancer, are related to smoking. Avoiding tobacco products in all forms may help prevent these cancers.
How is the disease diagnosed? Carcinoma in situ is diagnosed by taking a sample, or biopsy, of the area. This sample is sent to a laboratory to see if it is cancerous.
What are the long-term effects of the disease? Carcinoma in situ is likely to invade nearby tissue and spread to other parts of the body. Cancer that has spread, or metastasised, is fatal if it is not treated.
What are the risks to others? There is no risk to others from a person who has carcinoma in situ.
What are the treatments for the disease? Removing all of the cancerous tissue is the primary treatment. This can be done by surgery. Removing the cancer can also be done by destroying the area chemically, with chemotherapy, or with radiation therapy.
What are the side effects of the treatments? Because the affected area is small, the side effects and discomfort are minimal.
What happens after treatment for the disease? Sometimes, the presence of one carcinoma in situ can mean that others will form. The person will be monitored closely to see if carcinoma in situ comes back at the same spot or if a new one develops somewhere else.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
