Bowel cancer: The silent killer

by Ruth Laugesen / 18 February, 2013
More than 100 New Zealanders a month die from bowel cancer. Why don’t we have a screening programme?
Bowel cancer - the silent killer
Photo/Getty Images

Brent Wray, an active and healthy 64-year-old electrical engineer from Takapuna, felt perfectly fine. But early last year he was invited to take part in the Waitemata District Health Board’s pilot screening programme for bowel cancer, offered to everyone in the area aged between 50 and 74.

A day after he sent in his stool sample, his GP’s surgery rang to say it contained microscopic traces of blood, which is not uncommon. But the follow-up colonoscopy revealed a 7cm-long tumour growing in his bowel. Wray was astonished. He had had none of the warning signs, no abdominal pains, no changes to his bowel habits, no visible blood.

The news wasn’t all bad – there had been no spread to the surrounding lymph nodes. Surgery followed to remove the tumour and a section of the tube-like large intestine. The two ends were sewn together again to reconnect the bowel. In January, Wray finished chemotherapy.

“I feel like I’ve dodged a bullet,” says Wray. “It’s a silent killer. You don’t know what’s happening.”

Wray is one of 2800 New Zealanders diagnosed each year with bowel cancer, also known as colon cancer or colorectal cancer. About 1200 die of the disease each year, making it the country’s second-biggest cancer killer after lung cancer. An estimated $70 million is spent each year treating sufferers. Survival rates have improved in the past decade, as they have for many other cancers. But New Zealand still has one of the world’s highest death rates from bowel cancer in the world. By the time the average New Zealander turns 75, there is an almost 5% risk he or she will have developed bowel cancer, the third highest in the world after Slovakia and Hungary. Risks rise sharply after the age of 50.

And yet the cancer has a curiously low profile. Although friends standing around the barbecue will happily trade war stories about the other big cancers – melanoma, prostate, breast – they are unlikely to talk about tumours of the bottom and bowels, or discuss prevention and symptoms. The old taboos around women’s cancers of the breast and womb may have disappeared, but bowel cancer is still an unmentionable. The awkwardness around this part of the body means bowel cancer sufferers can feel particularly isolated, finding it hard to share with others details of their harrowing journey.

“We know that people are really embarrassed to talk about it,” says Rachel Holdaway, chairperson of patient advocacy group Beat Bowel Cancer Aotearoa, and a former sufferer. “People don’t like talking about bowels and bottoms and poohs. We encourage people to talk frankly and honestly and openly about it, hopefully to reduce the stigma that is associated with it.”

She and others set up Beat Bowel Cancer Aotearoa in 2010 because of what they saw as huge gaps in awareness of the disease. “Bowel cancer is a really significant health issue in New Zealand and I don’t really think enough is being done. Even if people recognise those symptoms, they feel quite held back in visiting their GP to investigate them.”


A Cancer Society study from 2009 found only half the population understood the signs and symptoms of bowel cancer, and a 2006 study found “low levels” of general knowledge about the cancer. The cancer’s invisibility extends to detection. Despite the epidemic of bowel cancer here, New Zealand lags by failing to offer a national screening programme. Australia, Canada, the UK and most of the rest of the European Union run screening programmes, but no decision will be made here until results from a Waitemata pilot are delivered in February 2016. Getting a programme running would take several more years, by which time thousands more will have died of bowel cancer.

Colorectal cancer is a slow-growing cancer that starts either in the rectum or in the 1.5m long large intestine that circles the bowel. Most tumours start as a benign polyp, a small growth on the wall of the bowel or rectum. About 30-40% of the adult population is thought to have such polyps, or adenomas, but only some become cancers.

A malignant polyp grows and takes up room in the bowel tube, sometimes blocking it. It goes on to grow through the muscle layers of the bowel and through its wall, and if not detected in time can spread to organs close by, such as the bladder, the uterus or prostate, or through the bloodstream to the liver, or to other organs through the lymphatic system.

Some patients have tell-tale symptoms – changes in bowel habits, blood in their stool or abdominal pain. But some notice nothing until it is very late in the piece. One recent New Zealand survey found that one in 10 cases were only discovered when sufferers turned up at accident and emergency departments with a bowel obstruction.

The good news is the rate of colorectal cancer peaked in the late 1980s and it has been falling since, partly because baby boomers seem less prone to it than their parents’ generation was. Based on current trends, by 2016 the risk of getting the cancer is expected to be a quarter what it was a decade earlier. And if someone is diagnosed, survival rates are up slightly: in 1999, 58% of colorectal cancer sufferers survived five years; by 2009 that had risen to 61%. Far fewer patients end up with a permanent colostomy bag, one of the dreaded hallmarks of the disease. Says Mike Hulme-Moir, a colorectal surgeon at Waitemata DHB and clinical director of the screening pilot, only about 10% of patients he treats need a permanent bag.

Mike Hulme-Moir: Bowel cancer surgery is “a much bigger deal than having a hip replaced or knee done [or a] hysterectomy”. Photo/David White.
But the treatment journey for this common cancer remains arduous, involving major surgery to a part of the body prone to infection. “It’s a big deal, it’s a really, really big deal. You take their insides and remove bits; you might need to give them a temporary bag. They have scars and they’re off work for six weeks. It’s a much bigger deal than having a hip replaced or knee done, and dare I say it, it’s a bigger deal than having a hysterectomy,” says Hulme-Moir.

As happened to Brent Wray, surgery often involves cutting out a section of the bowel and reconnecting the end. In removing a rectal tumour, the damage can be so extensive that a new rectum must be fashioned from the end of the colon and connected to the anus. Rates of complications after surgery are high, at about a third. “You’re dealing with a dirty organ – it’s full of bacteria. And you’re carrying out a procedure that physiologically challenges the body; it really creates stress on the body. Also many of the people we are operating on are elderly and have a whole bunch of other medical issues and that adds risk.”

In the best-case scenario, someone can be back at work six weeks after surgery, but that can stretch to months if there are complications. Chemotherapy, which is routine for all but the mildest cases, adds another six months to the recovery period.


So, why are New Zealanders so vulnerable to bowel cancer? “It’s not fully understood, but it’s probably related to lifestyle factors such as red meat and other dietary factors,” says University of Otago associate professor of public health Diana Sarfati. New Zealand has the fifth-highest per-capita consumption of beef and veal in the world, and we rate among the top three or four biggest meat-eating countries in the world.

Debate has long raged over whether red meat is a trigger for bowel cancer. However, the 2011 consensus report of the World Cancer Research Fund found there was convincing evidence that red meat, processed meat, alcohol in men and being overweight increased risk. Physical activity and eating foods high in dietary fibre decreased the risk of colorectal cancers. Taller adults also have a higher risk of colon cancer.

“What we do know is eating a lot of fresh fruit and vegetables and minimising fat intake, which includes not eating too much red meat, is generally good for your health,” says Sarfati.

Within New Zealand, rates of the cancer are highest in Southland, Otago, the West Coast and Canterbury; Maori and non- Maori rates are similar.

And University of Otago cancer epidemiologist Brian Cox has uncovered evidence of generational change. The early baby boomers have lower rates of the cancer than their parents. “People from about 1943 to 1960 have about half the risk of their forebears. We don’t know why that is. This reduced risk shows up at relatively young ages, between the ages of 25 and 29, so we know the major driver of bowel cancer in New Zealand is some sort of exposure that occurs before your 25th birthday.

“It could be some early exposures change the risks of developing adenomatous polyps in the bowel. And it may be that there are some aspects of adult diet that influence whether those adenomas develop into a full-blown cancer.” Factors in childhood might include diet, or they might be related to the combination of bacterial flora present in the gut.


Hulme-Moir says one of the heartening features of the screening programme is that he now sees more cases of early-stage bowel cancer, for which there is a 90% chance of successful treatment. “As a bowel cancer surgeon, I want to cure patients, and I know if we get them early we can cure them,” he says. Some tumours are so small they can be cut out at the colonoscopy stage.

New Zealand has a particularly atrocious record internationally in early detection of bowel cancer. A 2009 study that compared New Zealand with Australia, the UK, the US and Hong Kong found we had the lowest proportion of surgically curable, early-stage cancer. In this country one in five cases has metastasised, which is often considered a death sentence, by the time it is diagnosed.

The Waitemata screening trial, which began in October 2011, will run for four years at a cost of $26 million. Some 137,000 people in the Waitemata DHB area will be offered the faecal occult blood test, which is done using a stool sample. Fears people would not take part have been allayed, as more than half of those offered the test have taken it up – a high turnout by world standards. By September, almost 23,000 samples had been returned, with 1400 positive for microscopic traces of blood. Of those, more than 900 had a colonoscopy to look for signs of cancer.

Colonoscopies are one reason most of us never want to have to think about bowel cancer. As University of Auckland oncology professor Michael Findlay puts it, screening procedures for breast and cervical cancer are bad enough, but “to be told the screening process contains the potential for a 1m-long steel tube [to be inserted] up your bum, most people don’t go for that”.

The procedure, which is carried out under sedation and involves insertion of a flexible metal rod with a camera on the end, delivers impressive results. The operator can not only look for tumours, but also remove any precancerous polyps or any that are in the early stages of malignancy, lowering risks for the future. (As a bonus, the patient gets pictures of his or her insides to take home.)

Bowel cancer - Brent Wray had none of the warning signs of bowel cancer
Brent Wray had none of the warning signs of bowel cancer, no abdominal pains, no changes to his bowel habits, no visible blood: “I feel like I’ve dodged a bullet.” Photo/David White.

Figures from the screening programme show polyps were removed from 700 of the 900 people colonoscoped, a much higher rate than expected. A total of 35 cancers were detected and treated, corresponding to about 2.2% of those with a positive blood test. Although the latest figures have yet to be released, the number of cases of bowel cancer detected through the screening programme is now over 50, says Hulme-Moir.

Clinicians working in the field are impatient for national bowel cancer screening to go ahead. Beat Bowel Cancer Aotearoa is even arguing that the need for screening is so urgent it should proceed before the Waitemata pilot programme finishes.

How many lives might be saved? Overseas trials suggest screening can reduce bowel cancer deaths by 15%. But according to Otago’s Cox, in practice the number of lives saved would be smaller because of the difference between trials and the real world. He calculates actual lives saved each year would be 6.8% of those who die, or about 86 people. The estimated cost of a national screening programme is $60 million. Put crudely, that’s about $700,000 a life.

Would 86 lives saved a year be worthwhile? One comparison is the national breast-screening programme, BreastScreen Aotearoa, which offers screening at a cost of $56 million. On Cox’s estimates, this screening programme is preventing 5.3-7.5% of breast cancer deaths a year, representing 35-49 women’s lives, or half as many lives as a bowel screening programme.


Beat Bowel Cancer’s Holdaway considers Cox’s estimates make a strong case for bowel screening. “His figures just highlight how incredible and outrageous it is that we don’t have a commitment from this Government to a national roll-out of a bowel-cancer screening programme. We call on the Government to commit to this roll-out in the upcoming Budget.”

Cox favours a different kind of national bowel screening, using a flexible sigmoidoscope to view the rectum and a short part of the bowel, the area where two-thirds of the cancers are found. These would be offered once in a lifetime, not every two years as the faecal occult blood test is. The UK is to begin offering the test at age 55 as part of national screening. Cox has calculated 120 lives a year in New Zealand would be saved by doing something similar.

One reason the Government has been slow to move on a screening programme is that DHBs’ colonoscopy services are already stretched, and a screening programme would see an explosion in demand. Colonoscopies, which carry a risk of perforation of the bowel, are traditionally performed by gastroenterologists, and there is a reluctance by the profession to allow specially trained nurses to carry out the procedure. University of Auckland’s Findlay says some patients are already missing out on lifesaving treatment because of a logjam in the queue for colonoscopies to check out suspicious symptoms. He says ideally someone should get a colonoscopy within a week of being referred by their doctor after noticing symptoms. “We will often have someone who’s had a bit of blood waiting for three months on a colonoscopy waiting list. My concern is that I see a patient as soon as I can to give them their chemotherapy after their operation, because the later you leave it, the lower the chances the chemotherapy is going to work.”

The number of colonoscopies being offered in the public system is rising sharply, up one-third over the past four years to 41,000 in 2012. But as yet DHBs are not compelled to offer colonoscopies within any particular time frame.

The Ministry of Health has drawn up a plan, which it released to the Listener, for maximum waiting times of two weeks in urgent cases and no more than six weeks in other cases. However, the ministry has yet to get district health boards to sign up for this, and no date has been set for its implementation.

Findlay says anyone advised by his or her GP to get a colonoscopy should consider having it done privately, at a cost of $1500- $2800. “It’s a lot of money, but if you can get that part of it diagnosed quickly, then it’s a good start.”

Patients with bowel cancer that has spread to the lymph nodes have about a 65% chance of being cured with surgery and chemotherapy, says Findlay. “After that, it’s just a matter of lady luck being on your side.” And even for those for whom the cancer has quietly spread throughout their body before it can be diagnosed, chemotherapy can keep them going for some years. “That group of people in the old days, without chemo, had a 10% chance of being alive a year from diagnosis. Now at least 50% are alive at two years, probably getting near 70% with newer drugs. I now see people surviving over five years with an apparently incurable cancer,” says Findlay.

For Brent Wray, the screening programme was a stroke of luck, giving him an early diagnosis and excellent prospects for a full cure. He is happy to tell his story because he wants to break the silence around bowel cancer. “There is no modesty in medicine.”

Athlete’s lucky escape

After getting over early-stage bowel cancer, an Ashburton woman is working to raise awareness of the disease.

Rachel Holdaway was 41 and training for a duathlon. But instead of her usual fit, vigorous self, she was feeling bad. “It was getting to the stage where I couldn’t even complete the run part of my training.” She was exhausted, with legs that felt like lead.

“I also had overwhelming urges to go to the toilet; I was bleeding from the bottom. I put it down to increased exercise and haemorrhoids. I minimised my symptoms until it got to the point where I couldn’t ignore them any more.” After seeing her doctor, she had a colonoscopy.

She turned out to have a 4.5cm-long tumour on the wall of the rectum and was operated on towards the end of the same month, in May 2006. The cancer was not advanced and she didn’t require chemotherapy.

Rachel Holdaway took six months to feel well again.
Rachel Holdaway took six months to feel well again.

Recovery from surgery was slow, however. Her rectum was removed and a new one constructed from the colon. To allow that to heal, the large bowel was temporarily bypassed by making an opening in the stomach and bringing the end of the small intestine to the surface, a procedure called an ileostomy. This was then connected to an external bag that collected waste.

At first Holdaway found the bag “totally repulsive”, and couldn’t even look at it. But within a short time she became used to it and comfortable changing it. After eight weeks the ileostomy was reversed, “and they plumbed me all back up”.

“Initially, I did find it difficult to talk about it. But I’m over it now, and I like to be open about it because it’s just another part of the body like the heart or whatever.”

Holdaway, whose experience led her to set up a patient advocacy group for bowel cancer, Beat Bowel Cancer Aotearoa, says it took six months to feel well again. She quit her job as a pharmacy technician and now works on the family cropping farm near Ashburton, combining that with her advocacy work. She has been healthy since. “I feel I’m very lucky.”

Are you at risk?

See your GP if you notice any of the following:

  • Rectal bleeding

  • Changes in bowel habits, including diarrhoea or constipation

  • Feeling that your bowel doesn’t empty completely

  • Abdominal pain

Excessive worry is not the right response to bowel cancer symptoms. In most cases, the symptoms will have another cause. The Waitemata screening pilot is finding cancer is the cause in only about 2% of people with microscopic blood traces in the stool and other studies have found that symptoms at primary-care level are predictive of bowel cancer in only 5% of cases.

For 50-55-year-olds who can afford to pay and want peace of mind, many GPs are recommending colonoscopies because of the increasing risk of bowel cancer as people age. At 50 you have a one in 300 chance of getting the disease; by 60 that has risen to one in 100; and by 75 to one in 20.

Colonoscopies are particularly recommended for those with a family history of bowel cancer.

The highly invasive procedure costs $1500-2800. It involves insertion in the anus of a flexible metal rod with a wide-angle camera lens at the end of it. Pictures are transmitted to a monitor watched by a specialist, who scans the entire length of the colon. As well as looking for tumours, the specialist can remove potentially cancerous polyps.

Many people dread colonoscopies, partly because of a requirement to drink large quantities of laxatives the day before to purge the bowel, and partly because the procedure itself is undignified and can be uncomfortable. Sedatives and painkillers are used. The sedatives have an amnesic effect, meaning the patient often later forgets their discomfort. The procedure also carries a risk of perforation of the bowel, which is higher in older people or those with illnesses.

A newer, less intrusive option is a flexible sigmoidoscopy, a shorter probe that looks only at the rectum and the last part of the colon. The procedure costs between $1200 and $2000, is quicker and less uncomfortable, and usually doesn’t require purging. If any polyps are found, a full colonoscopy is often recommended.


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