When doctors diagnose rectal cancer, they assign a stage based on how advanced the disease is. Doctors use pathology results and imaging tests such as CT scans to stage rectal cancer.
There are five main stages: 0, I, II, III, and IV. Higher numbers indicate more extensive disease. Staging during diagnosis helps your doctor plan your treatment and follow-up care.
The stage assignment for rectal cancer depends on:
- If cancer cells are in your lymph nodes, which can cause the cancer to spread
- How deep the tumor has invaded the wall of your rectum
- Whether the cancer has metastasized, or spread, to other organs
To learn about stages of rectal cancer in the Bay Area, Find a Doctor online.
Understanding Rectal Cancer Stages
There are four stages of rectal cancer. Stage one indicates the least extensive level of disease.
Stage 0 Rectal Cancer
The earliest stage of rectal cancer is stage 0, or carcinoma in situ. The cancer is only in the outermost lining of the rectum, and has not spread. Doctors often find stage 0 cancers during a colonoscopy and remove them. Many times, further treatment is not required in this stage.
Stage I Rectal Cancer
Stage I cancer has grown deeper into the lining of the rectum. It remains confined to the rectum and has not spread to the lymph nodes. The primary treatment is surgery to remove the cancer and part of your rectum surrounding it. Treatment in this early stage is likely to be successful.
Stage II Rectal Cancer
Stage II rectal cancer has not yet reached the lymph nodes, but it has become very invasive. Early stage II cancers spread into the outermost layers of rectal tissues. Later stage II tumors have grown into nearby tissues or organs through the wall of the rectum. Treatment at this stage is still very effective and typically involves surgery and, sometimes, chemotherapy.
Stage III Rectal Cancer
Stage III rectal cancer has spread to nearby lymph nodes or tissues, but not to distant organs or body sites. For stage III rectal cancer, treatments can include surgery, chemotherapy, and radiation treatment. For certain stage III (and possibly stage II) rectal cancers, clinical trials of a new treatment may also be an option.
Stage IV Rectal Cancer
Stage IV cancer has spread beyond the rectum to other tissues and organs. Treatment options can include:
- Surgery to remove the cancer
- Chemotherapy and radiation to help treat symptoms and prevent complications
- Targeted cancer therapy
- Clinical trials of new drugs or combinations of drugs
Dignity Health’s cancer care team provides treatment for every stage of rectal cancer in the Bay Area, including San Francisco, Santa Cruz, and Redwood City.