Colorectal cancer or cancer of the large bowel, comprising the colon and the rectum, is common in New Zealand. (The lifetime risk is about 5-6% for the average New Zealander). In the majority of people with bowel cancer here is no single definable reason for the condition to develop however most cancers develop in preexisting benign polyps that of themselves may not cause symptoms. In about 5% of patients there is a dominant inherited gene that confers a very high chance of developing the disease. In a further 20% of patients there is a family history of the disease. Cancer of the rectum differs from colon cancer in that the affected organ lies deep in the pelvis and requires more specialised care to ensure optimal results.
What tests are conducted before surgery?
A colonoscopy is usually performed to diagnose a bowel cancer and a biopsy of the tumour is taken at the time to confirm the nature of the lesion. It is important to make sure that there are no other polyps or tumours elsewhere in the colon prior to surgery. If this is not possible then a colonoscopy is required after surgery.
To assess the clinical stage of the tumour (how advanced it is) a CT scan of the chest, abdomen and pelvis and an MRI scan of the pelvis is required. Additionally ultrasound of the tumour (ERUS) is performed. A blood test for a CEA (tumour marker) is taken for a baseline estimation.
How and why are radiation and chemotherapy given before surgery?
Previously recurrence of tumour in the pelvis was common after surgery for rectal cancer (25-40%). With improved surgical techniques and the use of pre-operative radiation therapy (sometimes combined with chemotherapy and called “chemoradiation”) a recurrence rate in the pelvis of 5% is now the norm. This treatment is given in one of two ways either “long course” or “short course”. (See page 4).
What does Surgery involve?
Surgery is performed under a general anaesthetic after bowel preparation. The diseased rectum is removed together with all the fatty tissue and lymph nodes surrounding it as far down as the anal canal, a technique known as Total Mesorectal Excision or TME. A “new rectum” is formed (where possible) by making a colon “J” pouch and joining this onto the anal canal. A temporary ileostomy (bag) is placed to divert the bowel motion away from the healing tissue for 6-8 weeks. In 10-12% of patients, due to the proximity of the tumour to the anal canal, it is impossible to safely rejoin the bowel without compromising the cancer operation. In this situation a permanent colostomy (bowel bag) is required. The need for this will be determined and discussed with you before the operation and appropriate counseling and information will be provided by the Stoma Nurses who will visit you at home before and after surgery and who will see you in hospital. A urinary catheter is usually left in place after surgery. A nasogatric tube is not routinely used. A hospital stay of between four and seven days is usual.
Key hole or laparoscopic surgery reduces the size of your incisions and speeds recovery. I will use this where possible provided it does not compromise the cancer surgery. Frequently a “hybrid” technique of part laparoscopic and part open is used in rectal cancer surgery.
What can I expect after surgery?
Some abdominal pain is usual after major abdominal surgery. Pain relief is achieved with wound catheters, a self-administered opiate pump (PCA of morphine or fentanyl) or an epidural. Bowel function usually returns 2-5 days after surgery but you may resume drinking on return to the ward.
Your nurse will get you out of bed on the first post-operative day.
A blood thinning injection is given daily and compression stockings will be fitted to reduce the risk of developing blood clots. The stoma nurse will educate you on how to look after your temporary ileostomy or permanent colostomy.
What can I expect when I get home?
Before you leave hospital you will be instructed to look after your temporary or permanent stoma by the stoma therapists. If you have a temporary ileostomy you require extra salt on your food , sugar and salt replacement drinks and some anti diarrhoeal tablets (Loperamide) to take home to prevent salt and water depletion.
All patients suffer from “post-operative fatigue syndrome” after surgery. In this period of four to six weeks you will feel tired after seemingly minimal exertion, either physical or mental. This is part of the natural recovery process and your energy levels will return to normal naturally.
If you have a temporary ileostomy a check x-ray (gastrograffin enema) of the colon pouch is performed at about 4 weeks and the ileostomy bag can be closed with a small operation, again performed under general anaesthetic, from 8 weeks after the main operation.
What are the possible complications of surgery for rectal cancer?
The most important complication of surgery for rectal cancer is a failure of the colon pouch to heal to the anus, a condition known as “anastomotic leakage”. This complication happens in about 10% of cases and is the reason that a temporary ileostomy bag is placed in surgery for rectal cancer. A temporary ileostomy reduces the consequences of this complication but not its frequency. A “leak” will delay closure of the ileostomy. Wound, intra-abdominal and chest infections may also complicate rectal cancer surgery. Blood clots in the legs and the lung may also occur after surgery. Measures are routinely employed to minimise the risk of all these complications but the risks cannot be totally eliminated. If there is a history of heart disease we will discuss your surgery with your cardiologist and anaesthetist.
Sexual function can be compromised in men after surgery for rectal cancer especially if a permanent colostomy is required. Please feel free to discuss this aspect of your treatment prior to surgery.
Treatment options and follow up treatment after surgery
Surgery remains the mainstay of the treatment of rectal cancer. Surgery alone cures 50% of all bowel cancers and over 90% of early cases. There is no evidence that “letting in the air” results in tumour progression. Detailed prognostic information will be available when the full pathology report is issued 10 to 14 days after surgery. Chemotherapy is used in two different ways in bowel cancer. “Adjuvant” chemotherapy is employed to improve the results of surgery in higher risk cases (usually with positive lymph nodes) even though there is no residual disease that can be seen on scans or at completion of surgery. If you have had pre-operative chemoradiation then completion of chemotherapy after surgery will be discussed with you by your medical oncologist.
Chemotherapy is a treatment option if there are liver or other secondaries that are unable to be surgically removed. In Wellington all radiation and chemotherapy is delivered at the Wellington Blood and Cancer Centre (Wellington Public Hospital) or at the private medical oncology unit (Bowen Icon Cancer Centre) at Bowen Hospital.
More information needed?
“Informed consent for surgery is a process not a piece of paper”! The expected outcome of surgery (return to health) must be weighed against the small chance of an adverse outcome or complication. If you require more information on any aspect of your condition or proposed treatment please make an appointment to discuss your concerns. Your general practitioner, medical or radiation oncologist or the cancer society will also provide information and or support.
Wellington Blood and Cancer Centre 04 806 2043
Bowen Icon Cancer Centre 04 896 0200
Wellington Hospital 04 385 5999
Southern Cross Specialist Centre 04 910 2178
Bowen Gastroenterology 04 479 8261
Cancer Society of NZ, Wellington division 04 389 8421
Cancer Society of NZ, Kapiti office 04 298 8514
Cancer Society of NZ, Wairarapa office 06 378 8039