The rectum is a reservoir that stores faeces at the end of the digestive system. It is quite commonly affected by cancer. The risk of cancer increases with age. A family history of bowel cancer also increases risk.
Rectal cancer may cause any of the following symptoms:
- Rectal bleeding
- A change in toileting habits with either looseness or constipation
- The need to rush to the toilet
- A feeling of never fully emptying the bowel
- “Wet wind” or the passage of slime
People with new symptoms suggestive of rectal cancer are investigated using a flexible fibre optic camera (colonoscope) that is passed into the bowel. If cancer is detected then CT and MRI scans are arranged to find out if it has spread to involve other organs. With this knowledge treatment can be tailored to the individual.
Treatment for rectal cancer
There are a number of different treatments for rectal cancer. Some cancers are small at the time of diagnosis and may be removed locally without the need for major surgery. Others cancers have grown to a large size and require radical surgery in order to remove the rectum. Pelvic radiotherapy may be given prior to surgery. This aims to shrink the cancer so that it can be completely removed by surgery.
Procedures for rectal cancer
Colonoscopy and Polypectomy: Cancer first arises within polyps attached to the bowel wall. These polyps often resemble cherries on a stalk and they can be removed quite easily using the fibre optic colonoscope. Sometimes this is the only treatment that is required.
Local excision: Small cancers of 2 or 3 cm in size can be treated by Transanal Endoscopic Microsurgery (TEMS). This is a keyhole style operation performed through the anus. The advantage of this approach is that it preserves the rectum and does not adversely affect quality of life as other treatments can.
Radical surgery - Anterior resection: The entire rectum is removed using either a keyhole or conventional open approach. Continuity of the bowel is restored as a new connection is made between healthy bowel and the anus. A temporary stoma might be necessary.
Radical surgery - Abdomino-perineal excision: In some cases a rectal cancer is situated so close to the anal sphincters that both the rectum and anus must be removed in order to ensure the best chance of cure. As the anus is removed bowel continuity cannot be restored. A permanent stoma is required. This is where the healthy bowel end is brought through the abdominal wall into a bag. The abdominal part of this surgery can often be performed using keyhole techniques. Sometimes the lower component of surgery is completed using the modern technique of “Extra-Levator Abdominoperineal” [ELAP] surgery, and reconstructive plastic surgery may be required using a muscle flap.
Pelvic exenteration: If a rectal cancer has spread to involve other organs within the pelvis (such as the womb or bladder), cure may still be possible; however, the involved organs must be removed. Our surgeons have special interests in pelvic exenterative surgery for locally advanced and recurrent rectal cancer.
Pelvic radiation therapy is a local cancer treatment that uses high-energy radiation to kill cancer cells within the pelvis. For rectal cancer treatment, radiation is most often applied before surgery (along with a small chemotherapy dose) to shrink the cancer so that complete surgical removal is easier and tumour recurrence following treatment less likely.
Chemotherapy is a whole body cancer treatment. Drugs kill cancer cells that have spread to involve sites not treated by surgery or radiotherapy. Selected patients receive this treatment once they have recovered from surgery to reduce the risk of the cancer returning.