Anal cancer staging refers to the size of the tumor, and whether cancer cells have spread to other body locations. Anal cancers fall into one of these six stages:
- Stage 0 (Carcinoma in Situ): Abnormal cells are found in the innermost lining of the anus.
- Stage I: The cancer has formed into a tumor which is 2 centimeters (cm), the size of a peanut M&M or smaller.
- Stage II: The tumor is larger than 2 cm.
- Stage III: The tumor is any size and has spread to:
- lymph nodes near the rectum, or
- nearby organs (urethra, bladder or vagina)
- Stage IIIB: The tumor is any size and has spread to:
- lymph nodes near the rectum and nearby organs (urethra, bladder or vagina); or
- lymph nodes on one side of the pelvis/groin, and may have spread to nearby organs; or
- lymph nodes near the rectum and the groin, and/or to lymph nodes on both sides of the pelvis/groin, and may have spread to nearby organs
- Stage IV: The tumor is any size, and may have spread to lymph nodes or nearby organs, and has spread to distant body sites.
Recurrent anal cancer: Anal cancer that has recurred after having been treated with chemoradiation.