The polyp police are coming
By Alan Cassels, October 2013
Are we ready for the consequences of a province-wide colon screening program?
The sign on the front of the podium said it all: “Screening Saves Lives.” It was April of this year and Health Minister Margaret MacDiarmid was speaking at a very important event. After a three-year pilot study in several communities around BC, she was announcing the official start of the new Provincial Colon Screening Program which was going to be unrolled on Vancouver Island this summer, before moving on to the rest of the province.
As she was announcing that program, few might have predicted the controversies that lay ahead; a summer where front page headlines were saying people who needed colonoscopies were facing massive line-ups and long waits for referrals to gastroenterologists. The new Health Minister Terry Lake had to face reporters to explain how they would fix things.
Some might say these were just growing pains for a province that has been somewhat slow in introducing a colon cancer screening program (at least six other provinces have already established their programs), yet screening large numbers of healthy people in the name of prevention is undoubtedly a complicated matter, both medically and politically. The praiseworthy goal is to reduce the rate at which British Columbians die from colon cancer—the third most lethal type of cancer in Canada—and BC’s program seems on the surface well-designed, but its implementation is not without its problems.
Within months of the program beginning on Vancouver Island, referrals to the island’s gastroenterologists, experts in assessing and treating people with a range of stomach and digestive problems, tripled. The ensuing waitlists for colonoscopies generated those headlines and the perception was set: People were being denied a lifesaving procedure.
BC’s program asks people to take a low-tech screening test before moving on to more complex, invasive and expensive tests, like the colonoscopy. The FIT (Fecal Immunochemical Test—essentially a take-home poop test) is offered free to all eligible BC residents between 50 and 74 years old. If you have a positive test (evidence of blood in the stool) you are eligible for a colonoscopy, which, done every ten years, is considered equivalent to the FIT every 1-2 years in terms of its ability to prevent or detect colon cancer at an early stage.
For people thought to be at higher risk because of their family history or a previous history of polyps, they can skip the FIT test and jump straight to a publicly-funded colonoscopy.
The simple fecal test costs our health care system only $35 per person to administer. It is an appropriate first-line screening tool as it can detect blood in the stool which might be an early sign of colon cancer. But there may be other reasons why there is blood in your stool: for example, hernias, ulcers, anal fissures. Sometimes even eating very rare meat can create a false positive. So, like any screening test, the problem of a false-positive result is always there.
A colonoscopy involves a long flexible scope, threaded through the anus and up into the colon to look for signs of bowel disease. If any signs of precancerous growth such as polyps are found, they can be removed.
It is believed by most medical authorities that finding and removing these polyps can reduce the risk of colon cancer. Currently, a typical Canadian faces a lifetime risk of a colon cancer death of about four percent. If a simple inexpensive FIT can improve those odds, it seems a reasonable and appropriate thing to do.
However, like all screening programs, colon screening is imperfect. There is much medical conjecture and debate about the relative values of FIT versus colonoscopy. Colonoscopies can find polyps and remove them, but they can also miss things. Also, at least a third of healthy people between ages 50 and 75 will have colon polyps. And here’s what you’re not likely to hear: Most of us will die with—but not because of—colon polyps.
Vancouver gastroenterologist Jennifer Telford is enthusiastic about colon screening. She was involved in piloting the screening program in BC and says it’s entirely appropriate that the stool test should precede a colonoscopy. She estimated that if we gave the FIT to 10,000 eligible BC residents, 8.5 percent, or 850 would go on to be recommended for a colonoscopy. Of those 850, about 34 cancers would be detected and about a third would have an advance neoplasia, or advanced polyps. These can be removed during the procedure.
“Colonoscopy is a great test and I love doing it,” says Dr Telford. Certainly removing polyps must be a satisfying enterprise because of the perceived benefit to patients. Dr Telford estimates that “75 to 80 percent of colon cancers come from precancerous polyps.”
But does a polyp automatically mean a death sentence?
Not at all—only about 2.5 polyps in a thousand will progress to cancer. There is much medical debate around how fast even “precancerous” colonic polyps will go on to develop into full blown cancers; estimates range from 10 to 25 years. Admittedly, finding things that could be precursors to cancer and then leaving them alone is very hard to do. Hunting down and removing polyps seems relatively easy to do and lucrative for those doing it.
But before fully embracing the program, we need to understand the problems colonoscopies themselves can cause both individuals and the health care system.
Volume clogging care
In early August, the Times Colonist reported that a young Oak Bay High graduate had sued VIHA for not arranging an early-enough colonoscopy when he had serious symptoms (blood in his stool, a swollen abdomen and fever) that needed investigating. He was told by physicians that a diagnostic colonoscopy was necessary to determine if it was Crohn’s disease or perhaps a carcinoid tumour—something that can be fatal if not detected early. But the 19-year-old got stuck in the four-month-long queue with everyone else getting a screening colonoscopy. (He has now had this test.)
Consumer advocate Wendy Armstrong of Edmonton isn’t surprised to see these sorts of delays now happening in BC. She has been monitoring the expansion of various screening programs for decades and what concerns her—watching how colonoscopies have been so eagerly promoted, sought and delivered in Alberta—is how the attention of gastroenterologists is consumed by, among other things, all the polyp chasing.
She tells me the story of a young man in Alberta, suffering a flare-up of Crohn’s, who was told he had an eight-month wait before he could get a colonoscopy. The problem, in Wendy’s estimation, is how busy the specialists can become “looking further at people with suspicious fecal tests.”
Unlike BC’s program—which requires the FIT first—Alberta publicly funds first-line colonoscopy screening. The growing numbers of colonoscopies performed in Alberta in the last few years has been staggering. In 2007, Alberta Health paid for 54,000 colonoscopies, yet by 2012 that number had increased to just over 107,000, a 100 percent rise in a province whose population grew just over 10 percent. This is, perhaps, why Calgary has been given the ignominious title of the “Colonoscopy Capital of Canada.”
The experience in Alberta is relevant because when you introduce a test that goes on to occupy the energies of the specialists, they may have even less time to treat genuinely sick people. With all the screening through colonoscopies, Wendy Armstrong says she has seen firsthand the “difficulty for people with debilitating symptoms of bowel disease—such as Crohn’s or colitis or even people showing clinical symptoms of possible cancer—to get timely and appropriate care.” After all, the time and availability of gastroenterologists are limited.
Unpredictable demand, unknown costs
BC’s program seems more rational than Alberta’s, yet with both provinces, access to specialists is related to the issue of unpredictable demand. When you offer a screening program, how many people will bite?
When I inquired earlier this spring, health authorities on Vancouver Island could give few precise details on the forthcoming screening program, such as the numbers to be screened, how many lives would be saved and the overall cost of the program. A 2010 UBC study suggested a cost of about $70 million per 100,000 individuals (in BC there are 1.345 million people between the ages of 50 and 74).
But calculations are not simple. Besides factoring in possible savings from earlier detection of cancer—which will take many years, maybe decades, to be realized—there are many other unknown factors: How many people will submit to screening? How many positives will be found? How many physicians will refer their patients to a colonoscopy without a positive FIT? And we can’t forget the costs associated with medical procedures needed to fix people who are injured by a colonoscopy.
The BC Cancer Agency’s Angela Wilson told me by email that “FIT use in the first three months of availability has been [25 percent] higher than expected. Patients with positive FIT would be referred to colonoscopy; therefore colonoscopy referrals have been higher than anticipated as well.”
Wilson also said that “the Ministry of Health has estimated the annual program cost to be $10 million,” though those costs could be much higher.
There are many things which might drive (or reduce) demand for colonoscopies. One of the things that drives consumer demand for screening is the celebrity factor. When TV personality Katie Couric had her colonoscopy done live on the Today Show, there was a 20 percent spike in colonoscopies in the US. Celebrity endorsements might be the last place one should go for health information, but knowing someone who has died from colon cancer (or believing one’s life had been saved because of a polyp removal) surely contributes to the demand for colonoscopies.
What does the evidence say about the difference between the FIT test and colonoscopies? Dr James Allison, a gastroenterologist and clinical professor of medicine at University of California, San Francisco says BC’s colon screening program seems “conservative and appropriate.” He has written extensively on the lack of evidence to support the popularity of colonoscopies, telling me that there is “no proof from randomized controlled trials that colonoscopy every 10 years is superior to FIT every year in decreasing colorectal cancer incidence and mortality.” In other words, the colonoscopy is not any more “lifesaving” than having the poop test every year or two.
So how effective is the fecal test? Like many screening programs, many of us have to be screened in order for one person to benefit. Dr James Penston, a UK gastroenterologist, criticizes colorectal screening as “being sold to the general public on the grounds that it saves lives. But there’s no evidence for this claim.” He points to a large 10-year study in the UK of colon cancer screening using the fecal occult blood test. In the control group (those not screened) the death rate for colorectal cancer was 0.8 percent. It was 0.7 percent in the screened group. This 0.1 percent difference translates into a one-in-a-thousand benefit.
A new study published in the prestigious New England Journal of Medicine in late September looked at 30 years of follow-up for more than 46,000 people undergoing annual or biennial fecal blood screening for colon cancer. Those undergoing screening were less likely to die from colon cancer (by about 6 in 1,000), but overall death rates in screened and unscreened populations were the same. So the Minister's sign that “Screening saves lives,” at least in this case, isn’t proven by the evidence.
Perhaps more important, how many will be given colonoscopies that lead to bleeding, hospitalization, perforation and, occasionally, death? Unfortunately, we won’t know the answers and hence the overall outcome until the program has been in place for a very long time.
Overdiagnosis, overtreatment and harm
In the last few years even the most-studied and widely-used screening programs (for breast and prostate cancer, for instance) have faced evidence-based arguments about whether they were doing more harm than good. The main issue has been the possibility of overdiagnosis. In the case of colon cancer, because most of us will have polyps and very few of us will die from them, screening is also liable to result in overdiagnosis and overtreatment.
If and when polyps are found, people may live under a dark cloud, with a “pre-cancerous” label for the rest of their lives. They will certainly be more frequently reminded of their colon health because they will receive many future invitations for follow-up colonoscopies. There is some evidence that depression and suicide is higher among those who submit to screening programs.
Dr Gilbert Welch, author of the book Overdiagnosed: Making People Sick in the Pursuit of Health, knows well the downsides of screening. In an article he wrote for the New York Times last year he said that “screening the apparently healthy potentially saves a few lives…but it definitely drags many others into the system needlessly—into needless appointments, needless tests, needless drugs and needless operations…” He argues that the process of screening doesn’t promote health but rather promotes disease. “People suffer from more anxiety about their health, from drug side effects, from complications of surgery. A few die. And remember: These people felt fine when they entered the health care system.”
In addition to the psychological effects of screening, the downsides to an actual screening colonoscopy can include the side effects of ingesting the bowel preparation (including bloating, gas, stomach pain, feeling very hungry and dehydrated), as well as cardiac arrhythmias, and other metabolic disturbances, and even neurological damage.
When Deb Novak, a 56-year old native of Edmonton agreed to have a screening colonoscopy, like many people she was seeking an ounce of prevention. When Novak arrived for the procedure, the clinic was crowded with others waiting for their colonoscopies. Despite the mild sedation she found the colonoscopy painful and at one point a searing pain caused her to scream out and struggle to jump off the table. When the procedure was over the doctor said they had found a single mushroom-like polyp and removed it. That should have been the end of the story.
But it wasn’t. She spent most of that night vomiting and in severe pain. A late-night ambulance ride back to the hospital and a near 12-hour, agony-filled wait in the emergency room left her feeling abandoned and bitter. She said that it appeared the screening program “had no back-up plan for a return in the case of a perforation emergency.” During the emergency operation to repair a seven-centimetre perforation of her bowel, Novak thought to herself, “I think I’m going to die.” She had to rely on a colostomy appliance for a year before they could repair her torn intestine.
While only a small proportion of colonoscopy procedures turn out as horrendous as Deb Novak’s, colonoscopies for some people can be fatal. Studies show a .5 percent risk of serious medical complications from colonoscopy—one person in 200.
There’s also the opposite possibility, that a patient will get stamped with a clean bill of health after a colonoscopy when the scope missed something. This is common “even among expert examiners who know that they are being scrutinized,” said one study. In fact, as Deb Novak tells me, the doctors doing the emergency repair to her perforated colon found a polyp that had been missed during the original colonoscopy.
Inflating the demand
For some diseases of the digestive system, such as Crohn’s and colitis, getting a close-up view of a colon with a colonoscopy can be an incredibly valuable tool. After all, these are people who have clear symptoms of pre-existing bowel diseases and a diagnostic colonoscopy is a great way to find out more about their condition.
But when used purely as a screening method, it’s worth reminding ourselves of the financial incentives shaping who gets screened, how often, and for what purpose. Physicians in BC don’t make a ton of money doing a colonoscopy (MSP pays them $230.62 for a colonoscopy or $344.79 if a polyp is removed), but when you add all the additional costs—the anaesthetist’s time, the nurse, equipment and admin costs—the bill to the tax-funded system could be as much as $1000. And of course if you have complications, bleeding or perforations, it’s back to the hospital for even more medical interventions and costly treatment.
In the private sector, a screening colonoscopy can be bought for $1600 at a place like the False Creek Healthcare Centre in Vancouver. When I called inquiring about the program, I was told that I’d be in good hands because “all the doctors are gastroenterologists who work in the public system.”
There are a limited number of gastroenterologists in the province. If they can get (or their private facility can get) $1600 for a colonoscopy for 20-30 minutes of work, and only $344 for removing a polyp in the public system, guess where most of them are going to work? That’s exactly what they found happened in Alberta. This understandably results in more stress on the public system, making delays more likely for those who are suffering symptoms that require a scope to help determine their cause.
Wendy Armstrong, who is a past president and current researcher for the Consumers Association of Alberta, was an official intervener in a recent public inquiry in Alberta examining alleged preferential access in the public healthcare system.
The inquiry found that some private patients were getting booked for screening colonoscopies in weeks or months in private clinics while others waited two to three years to get the procedure in the public system. It also found that some patients were being recalled for follow-up colonoscopies more frequently than recommended by current guidelines. In Wendy’s opinion, the potential for inflating demand for colonoscopies (inside and outside the public system) was huge and that the wait-time problems and frustrations that we are seeing in BC are entirely predictable. She told me, “what came through loud and clear was that doctors in these boutique clinics are shopping for ‘healthy users.’” By overscreening healthy, better-paying private clients, the sick and the more needy (those with real symptoms) will inevitably get shunted to the back of the line, or stuck in the line with everyone else, like that poor Oak Bay student. There is a name for this: It’s called the “inverse care law,” which can be re-tweaked here to be the “inverse screening law”—which is to say, the availability of a service, in this case screening, is in inverse proportion to its need.
Spending $10 million or more of public health dollars every year to avoid a fatal disease seems on the surface like the right thing to do, but we always have to ask: What kind of overall impact will this screening program have? Will other important public healthcare services or programs be cut or clawed back to pay for the growing costs of this program? Have they been already? And are there better, perhaps more efficient ways to reduce the burden of colon cancer? We know, for example, that better diets (less meat and processed food), more exercise, not smoking—the usual triumvirate of better health advice—is crucial to help us all live longer and healthier lives. Want to reduce your risk of colon cancer? Eat more vegetables and ride your bike (as well as talk to your doctor about your family risk and how you might benefit from colon cancer screening).
From my perspective as a researcher, we need better evaluation of existing screening programs to estimate the benefits; better predictions so we can estimate the burden of the program on the gastronenterology profession; and better information so that people go into screening knowing what to expect—both the potential benefits and potential harm—so they can opt out if they don’t like the odds presented to them. At the end of the day, well-informed citizens, not physicians or the government, should determine if they want to submit to a colon screening program around which there are many questions and unknowns.
Alan Cassels is the author of Seeking Sickness: Medical Screening and the Misguided Hunt for Disease and he has worked for the last 18 years as an administrator, researcher and consultant on research and evaluation projects supported by the provincial and federal governments.