Rectum is an organ hidden deep in the pelvis (hip bone). Conventional open rectal cancer surgery is difficult due to poor visibility (see image). However, robotic & laparoscopic rectal cancer surgery gives better quality vision to the surgeon. A laparoscopically skilled cancer surgeon can operate using laparoscopy giving superior results to a rectal cancer patient. With laparoscopic rectal cancer surgery, the trauma is much less and that makes the treatment more acceptable to the patient.Robotic surgery is more advanced form of laparoscopy making it easier to perform more complex surgeries, especially for those tumors lying very low in the rectum and after chemo-radiotherapy. Robotic surgery makes it possible to preserve anus in more number of patients.

Large bowel is made of colon and rectum (back passage). The rectum is the final straight portion of the large intestine. It terminates in the anus. The human rectum is about 12 cm long.

Rectum stores our waste before defecation. An intact anal sphincter or muscles is required for holding the waste (feces) till defecation. Tumors of this portion of large bowel are relatively common.

Most common type of cancer is adenocarcinoma. Rare tumors like melanomas, gatro-intestinal stromal tumor (GIST) and lymphomas are also seen in rectum.

The stage of rectal cancer can only be confirmed after surgical removal of tumor. However, imaging studies like CT scan or MRI scan give good idea about the stage of the disease in many cases.

Surgery is the main treatment of rectal cancer. All the rectal cancer surgeries can be done robotically or laparoscopically with great advantage to the patient.

Stage 0:

Stage 0 rectal cancer is when the disease is limited to the innermost lining (mucosa). While performing endoscopy, an endoscopist can exise it completely (polypectomy). When performed properly, this would serve as complete treatment. However, often more extensive surgery (resection) to remove rectal cancers is required (discribed in next session). Surgery can cure cancer at this stage.

Stage I

Stage I rectal tumors are the ones that have spread beyond the inner lining (mucosa) to the second and third layers. The cancer has not spread outside the colon. Standard treatment involves surgery to remove the cancer (described in next session). Additional treatments like chemotherapy and radiotherapy are not usually needed. Aggressive surgery has the potential to cure this cancer. The five-year survival rate for this stage is more than 90%

Stage II

Stage II rectal cancers are larger and extend through the muscular wall and may have invaded other organs, like the bladder, uterus, or prostate gland. However, there is no cancer in the lymph nodes (small nodular structures that are present throughout the body that clear the tissue fluids). Standard treatment is surgical removal of the cancer (described in next session). When this stage is detected before surgery by CT scan or MRI scan, radiation therapy along with chemotherapy (5FU or Capacitabine) is given for better long term results. If not, the same may be given after surgery. The five-year survival rate for stage II is 78%

Stage III

Stage III rectal cancers have spread outside the rectal wall to the lymph nodes (small nodular structures that are present throughout the body that clear the tissue fluids). Lymph nodes are one of the first to get affected by spreading cancer. The treatment involves multiple modalities:

• Surgery to remove the tumor and all involved lymph nodes (described in next session).
• Radiation with or without chemotherapy has to be given before or after surgery (your oncologist will decide about the timing). When given before, this may help in reduction of size of the tumor and preservation of anus (Avoiding permanent colostomy and feel normal).

The five-year survival rate for stage III rectal cancer is about 64%

Stage IV

Stage IV rectal cancers are the ones that have spread to far away organs. Usually these include liver or lung. The mainstay of treatment is chemotherapy, but surgery to remove the tumor may also be recommended. Surgery, when performed, is often used to relieve or prevent blockage of the rectum or to prevent rectal bleeding. A curative surgery may be considered in selected cases where all the tumor tissue can be surgically removed (limited number of liver & lung spread). When surgery is possible, the five-year survival rate can be upto 50%.

When surgery is not possible, other options include destroying them with microwaves or heat (radiofrequency ablation) or giving chemotherapy directly into the liver used with embolization (chemoembolization), etc.