“Flexible Sigmoidoscopy Should Be Encouraged”
I would like to comment on the two reports from Baltimore on the subject of colonoscopy as a screening tool (“Symptoms not enough to predict women’s colorectal CA,” and “Colonoscopy screening: specialists walk the talk,” the Medical Post, Nov. 4, 2003).
One was a large retrospective study done by Dr. Radhika Srinivasan of the University of Pennsylvania Medical Centre in Philadelphia.
Dr. Srinivasan said most symptoms of colorectal cancer are poor predictors for the presence of the disease. Since colon cancer can occur without any symptoms, Dr. Srinivasan recommends screening colonoscopy for men and women over the age of 50.
The second study was by Dr. Prem Chattoo of St. Vincent’s Hospital in Manhattan, New York. His study showed 70% of gastroenterologists older than 50 years have had a routine screening colonoscopy, compared to about 15% of patients age 50-plus in the general population.
This finding is not surprising. We know screening for colorectal cancer saves lives. But the ideal method of screening remains controversial. Dr. Chattoo’s finding suggests the general public and the referring physicians are still not convinced an asymptomatic person over 50, with no risk factors, needs to undergo screening colonoscopy.
In Canada, my impression is the percentage of asymptomatic patients, at average risk for colorectal cancer undergoing screening colonoscopy, is probably less than 15%. Although colonoscopy remains the gold standard for screening, it is not without disadvantages.
There is a fair amount of waiting before a patient can get in for a consultation. Then there is more waiting before the patient gets a procedure. In the meantime, the patient wonders whether he has cancer or not.
Colonoscopy is as good as the skill and patience of the operator. There is a small risk of bleeding and perforation. Some patients react adversely to sedatives used during the procedure.
Endoscopy time in a hospital setting is at a premium and takes up a significant amount of hospital resources. There is a fair amount of inconvenience to patients and their families before and after the procedure (bowel prep, taking time off work, getting a ride to and from hospital, etc.). There is a great amount of anxiety about the procedure and waiting for the results.
It is estimated colonoscopy costs our health-care system about $1,000 per procedure. Eighty-five per cent of colonoscopies are usually normal and 95% of colonoscopies do not show any cancer.
Gastroenterologists and other GI endoscopists (I used to be one) are keen on promoting colonoscopy as a screening procedure. But somehow, either there is a credibility gap or there is failure in communication. Or there is no convincing argument that screening colonoscopy is as good as screening mammography or Pap smear.
What about symptomatic patients? Do all patients with lower GI symptoms need colonoscopy? Are there other tools that can be used safely and appropriately?
Flexible sigmoidoscopy is a good instrument for symptomatic patients under the age of 40 or even 50 if their symptoms are hemorrhoidal in nature. Patients younger than 40 have an incidence of colorectal cancer anywhere from 1% to 6%. Overall, for an average risk patient the lifetime risk for developing colorectal cancer is 5%.
Flexible sigmoidoscopy has many advantages. It is being underused and undervalued by many endoscopists and physicians. It is safer than colonoscopy. It is easy to perform in an office setting and does not require hospital resources. It is highly sensitive within the distance.
It is a good test for younger patients especially those who have symptoms related to the ano-rectal area. It is a good test for older patients at low risk for colorectal cancer. It is a useful test for reducing the waiting list for colonoscopies. It will make room for symptomatic patients who really need colonoscopy on an urgent basis for whom sometimes it is impossible to find a spot.
Most endoscopists find it easier to book patients for colonoscopy in a hospital than to do a flexible sigmoidoscopy in an office. This is quite a natural process as most endoscopists spend more time in hospital looking after sick patients.
Besides, to buy and maintain a flexible sigmoidoscope in an office requires a fair amount of investment for equipment and staffing. Naturally, the overhead goes up. Hence there is no incentive for physicians to set up a system in the office.
I have been doing flexible sigmoidoscopy in my office for the last 13 years or so. I think flexible sigmoidoscopy should be encouraged and promoted as a good test for many patients. Better fee schedule for the procedure would certainly help. Dr. Noorali Bharwani, Medicine Hat, Alta.
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