PREVENTION AS A CURE
Issue: Preventing cancer saves far more lives than any drug but gets little financial or scientific support. Possible solutions: Assign a larger portion of cancer dollars to finding the disease’s causes and preventing known risk factors.
It started for Sandra Huggett almost like a daytime-television plot twist.
Healthy, active and relatively young, the Prince George, B.C ., resident developed a cough in late summer 2014 that refused togo away. Several doctor visits were inconclusive, but then an X- ray revealed an ominous shadow on her right lung — and led to the worst kind of diagnosis.
Huggett learned that December she had stage- four lung cancer, the malignancy having already spread to her kidney and several bones.
By June 2015 the kindergarten teacher, who had two daughters of her own — now 11 and 14 — was in palliative care, her mind ravaged by cancer that had also invaded her brain. Huggett died February 2016 at just 55 years old.
“To see Sandra age and then quickly lose her cognitive ability, her speech, her memory, her ability to walk and care for herself … It was all gone very quickly,” said her husband Alan.
Huggett never smoked and there is no way of definitively proving what made her sick, but signs point strongly in one direction. Testing after her diagnosis revealed the family’s house had three and a half times the safe level of radon, a colourless, odourless gas that is found throughout Canada, and considered the second biggest cause of lung cancer after tobacco.
Though tragic ally too l ate for Sandra Huggett, the radon findings underline one hopeful aspect of cancer. In many cases, with foresight, cancer can be prevented — humans do have some control over a frighteningly unpredictable disease.
At the Huggett’s house, Alan has all but eliminated the invisible radon menace with retrofits that cost less than $1,500.
Prevention is also a notion under siege. A 2015 study co- authored by a star researcher concluded that two- thirds of cancer risk actually stems from random cell divisions — “bad luck” — throwing the importance of avoidable risk factors into question.
Those findings have been vigorously debated since. But prevention as an anticancer strategy, despite its unmatched track record for saving lives, faces an even greater threat — from simple neglect.
In a multibillion- dollar sector, efforts to stop people from contracting the illness in the first place are something of an afterthought, accounting for as little as five per cent of what’s spent.
That’s l ef t Canadians largely in the dark, for instance, about radon’s risk. Less than a third even know what it is, and barely three per cent of non- apartment dwellers have tested for the gas, according to a 2015 federal survey.
Research to i dentify more of cancer’s causes has slowed sharply, too. The number of Canadian scientists doing the work is probably half of what it was in 1985, said Jack Siemiatycki, an internationally renowned cancer epidemiologist at the University of Montreal.
He said the Canadian Institute for Health Research, the chief federal medical-science funding body, devotes just one to two per cent of its cancer budget to the task and has repeatedly rebuffed calls to make it a priority.
“It’s why the cancer problem is as big today as it was when ( President) Nixon declared the war on can- cer,” said Siemiatycki, who holds t he Guzzo Cancer Research Society chair in environment and cancer. “We haven’t won that war because we have been fighting on the wrong front, or at least we haven’t been fighting on the front where we could have a major impact.”
Intriguingly, he believes that one day scientists will have identified preventable risk factors for virtually all cancers – assuming they get sufficient resources.
Other experts estimate that 40 to 50 per cent of malignancy is avoidable now — the result of lifestyle or environmental influences that range from unprotected sun exposure to obesity.
But Siemiatycki sees that number as a moving target, and said most cancers likely have both a genetic, non-preventable aspect, as well as one that relates to the patient’s own behaviour or environment.
While tobacco is the most powerful carcinogen, for example, only about 10 per cent of heavy smokers will get lung cancer, suggesting they have a hard- wired propensity for the disease that works hand- in- glove with the habit itself. John Spinelli, a B. C. Cancer Society scientist and University of British Columbia (UBC) professor, is not convinced that all cases will turn out to be preventable, but thinks it might eventually reach as high as 80 to 90 per cent.
Such optimistic views of prevention’s potential, t hough, t ook a s eri ous beating in 2015, when the journal Science published a paper by two Johns Hopkins University researchers, Cristian Tomasetti and Bert Vogelstein.
They hypothesized that the novel reason some of the body’s tissues are more vulnerable to cancer than others – the lung is 11 times more likely than the brain to be affected by the disease — is strongly related to the number of times the organ’s stem cells divide, and the DNA mutations that result.
Comparing data on stemcell divisions with cancer statistics for different parts of the body, they concluded that this random process explained the development of tumours better than any environmental or inherited factor.
In fact, they added pro- vocatively, two- thirds of cancer risk is likely just “bad luck.”
The work essentially identified a third, random component in the development of cancer, on top of environmental and inherited triggers, Tomasetti said in an interview. He agrees two or three of those elements can act together in many instances, and that prevention remains important, but doesn’t believe we’ll ever get to a point where all cancers are avoidable.
Instead, the bio- statistician recommended enhanced focus on early detection, giving even the purely unfortunate patients a better chance at survival.
“This really is a paradigm shift and it has strong implications for research direction,” said Tomasetti.
A slew of articles and letters to the editor later called the team’s methodology and findings into question, criticisms they tried to address in a sequel study.
In the meantime, though, a less- esoteric defence of prevention’ s role lies simply in the history of the last 50 years, when one factor reduced cancer’s toll like nothing else before or since.
The dramatic plunge in smoking rates since t he 1960s has saved 800,000 lives in the United States al one and accounts f or most of the recent drop in cancer mortality, a 2012 American study concluded.
If any basic science or drug discovery had made even close to that impact, the scientists behind it would have been lining up to accept their Nobel prize, said Siemiatycki.
“Cu ring cancer gets votes,” said Siemiatycki. “There are no grateful people saying, ‘ Thank you for preventing my bladder cancer.’ “
Spinelli, at the B.C. Cancer Society, would like to see additional dollars spent on large “cohort” studies, where tens of thousands of subjects are followed closely overtime with blood tests and questionnaires, teasing out why some get cancer and others do not. One involving 300,000 Canadians is underway, but it should just be the beginning, he said.
Meanwhile, countless more lives could be saved by taking advantage of what we know already about risk factors.
Unique estimates by Cancer Research U. K. suggests reducing obesity would prevent up to 18,000 cancer cases in Britain a year, eating more fruit and vegetables 15,000, less alcohol 13,000, and better sun protection 11,000.
Of course, knowing what’s preventable, and knowing exactly how to prevent it are two different things.
Spinelli argues that further curbing the population’s risk will likely require broad, structural changes, policies that make fresh produce as cheap and accessible as Big Macs, or cities more walk- able.
Yet, as Sandra Huggett struggled with her own, likely avoidable disease, her husband Alan saw lessthan- hopeful evidence of health care’s priorities. The cancer centre in Prince George provided top- notch care, he said, but its “prevention office” was a little, windowless room, staffed parttime by a single worker.
“Tome, it’ s ass-backwards ,” he said .“You have all these millions of dollars of cancer treatment stuff, and then you have a dinky little cupboard, basically, for prevention.”
TO SEE SANDRA AGE AND THEN QUICKLY LOSE HER COGNITIVE ABILITY, HER SPEECH, HER MEMORY, HER ABILITY TO WALK AND CARE FOR HERSELF … IT WAS ALL GONE VERY QUICKLY. — ALAN HUGGETT, SANDRA’S HUSBAND