Stage 0 or carcinoma in situ (Ts, N0,M0)
Surgery to remove the cancerous tissue and surrounding healthy margins including:
- local excision
If pathology reports show that the polyp or lesion was completely removed, margins are clear of cancer cells, and there are no unfavorable signs, then watching carefully for possible recurrence is appropriate.
If the lesions were not completely removed, cancer cells remain in the margins, or the tumor extends farther than the inner lining of the rectum (T1), then additional surgery is recommended.
Stage I (T1 or T2,N0,M0)
The tumor is limited to the inner three layers of the rectum but has not spread outside its wall, lymph nodes show no sign of being involved, and there is no sign that cancer has spread beyond the rectum.
- Local excision through the anus.
- Low anterior resection (LAR) for tumors that are high enough in the rectum to permit reconnecting the colon or rectum to the anus (anastomosis).
- Abdominoperineal resection with permanent colostomy when the distance between tumor and anus is too short to allow safe anastomosis.
Adjuvant treatment after surgery
Follow-up (adjuvant) treatment depends on what the pathologist finds when the surgical specimen is examined.
After transanal local excision
If the tumor is confined to the inner walls of the rectum (T1), margins are clear, and there are no high risk features, patients can be observed with follow-up surveillence.
If there are signs that that recurrence is more likely, a second operation through the abdomen (LAR or APR) may be called for. High risk signs include:
- T2 tumors that extend into the outer muscle layer of the rectum.
- Tumor cells are poorly differentiated — look very different from normal cells around them.
- Cancer cells are found in the blood and lymph vessels just outside the rectum (lymphovascular invasion)
- Margins are not clear of cancer cells
After abdominal surgery
If pathology shows that the cancer remains Stage I (T1 or T2 with no spread to lymph nodes or distant sites), observation with follow-up surveillance is appropriate.
If the tumor has gone through the outer layer of the rectum (T3) or there are cancer cells in lymph nodes (N1 or N2) then follow-up chemotherapy and chemoradiation may be recommended. Adjuvant treatment is usually a “sandwich” of chemotherapy, chemoradiation, and additional chemotherapy.
- 5-FU with leucovorin or FOLFOX or Xeloda (capecitabine)
- radiotherapy with either continuous infusion 5-FU or Xeloda
- additional 5-FU with leucovorin or FOLFOX or Xeloda (capecitabine)