Staging systems provide doctors with a common language for describing tumors. After cancer is first diagnosed, a series of tests are used to investigate the extent of the cancer and to see whether it has spread to other parts of the body from where it started. Staging is a way of recording the size and growth of a cancer, and determining the plan for treatment. By understanding the stage of your cancer, you can make informed decisions about your treatment.
Staging anal cancer attempts to discover the following:
- The size of the tumor
- Whether the cancer has spread to nearby tissues
- Whether the cancer has spread to other parts of the body
Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all the tests are finished. Based on the results of exams and tests, anal cancer is staged as follows:
- Stage 0. Abnormal cells are found only in the innermost layer of the anus. Also called carcinoma in situ.
- Stage I. Cancer has formed and the tumor is 2 cm or smaller.
- Stage II. Tumor is larger than 2 cm.
- Stage III. One of the following:
- IIIA. Tumor is any size and
- Has spread to either the lymph nodes near the rectum.
- Has spread to nearby organs such as the vagina, urethra and bladder.
- IIIB. Tumor is any size and
- Has spread to nearby organs and lymph nodes near the rectum.
- Has spread to lymph nodes on one side of the pelvis and/or groin and may have spread to nearby organs.
- Has spread to lymph nodes near the rectum and in the groin and/or lymph nodes on both sides of the pelvis and/or groin and may have spread to nearby organs.
- Stage IV. The cancer has spread (metastasized) from where it started to lymph nodes, nearby organs and distant parts of the body.