YOUR CANCER ODDS ARE 50/50
Decoding the disease’s shocking stats
Last year, the Canadian Cancer Society announced that nearly one in two Canadians would get cancer in their lifetimes. Scary stu . Surely, there’s more story behind the headline, no? Health writer Anna Sharratt is on the case. Here’s what she discovered.
SANDY KRUSE’S DAUGHTER IS THE “ONE” IN THE scary stat that says one in two Canadians will get cancer in their lifetime. Sandy is the “two.”
Kruse’s daughter was just five when a sarcoma, a softtissue cancer, was discovered in her arm. As her daughter went through treatment at Toronto’s SickKids hospital, Kruse endured the most stressful year of her life.
So when she developed a migraine with an aura in August 2011, she chalked it up to stress. But a doctor felt such intense headaches should be investigated. He ordered tests, which revealed that Kruse had five nodules growing on her thyroid. Further testing by an endocrinologist revealed that one of the five nodules was papillary carcinoma.
Because she had bilateral thyroid nodules, she underwent a thyroidectomy — the complete removal of the thyroid. “The surgery wasn’t that bad,” she said, though taking thyroid hormones to replace the lost gland was challenging. As she struggled with the right combination of thyroxine (T4), she had “zero energy, brain fog, fatigue and hair loss.”
Doctors experimented with the hormones and found a combo that worked. And Kruse changed her lifestyle, incorporating daily workouts and eating clean. Fast-forward seven years and both Kruse and her daughter are cancer-free. “I’ve changed how I eat, how I live,” says Kruse. “I’m a totally different person than I was.”
CANCER'S CHANGING FACE
When the Canadian Cancer Society announced last spring that nearly one in two Canadians would get cancer in their lifetimes, it sent shock waves through the population. The report revealed that Canadian men have a lifetime cancer risk of 49 percent, while Canadian women
have a lifetime risk of 45%. Does this mean that stories like Kruse’s will become more commonplace? Does it mean that there is no sense in living a clean lifestyle?
THE REAL STORY
Well, not so fast. In fact, there are explanations behind these alarming numbers that help reduce the panic. For one thing, the data reflected a change in methodology, which was new for 2017 — the result of extensive consultation with the society’s advisory committee. Previous analysis by the Canadian Cancer Society, The Public Health Agency of Canada and Statistics Canada had only focused on people who hadn’t yet developed cancer — the new data included cancer survivors, explains Dr. Leah Smith, senior manager, cancer surveillance at the Canadian Cancer Society.
Another big factor in the new statistics is Canada’s aging population. “The population is getting older,” says Dr. Smith. “[And] it’s important to understand that cancer is a disease of the aging.” As people live longer, they are at higher risk of cancer with each passing year. “Eighty-nine percent who are diagnosed are over 50,” she says.
Dr. Smith stresses that the “overall rates of cancer have not increased in Canada.” And that the 1 in 2 risk is comparable to the lifetime risk in countries such as Australia, the U.S. and the U.K.
Dr. Anthony Miller, professor emeritus at the Dalla Lana School of Public Health at the University of Toronto, agrees that there’s no reason to sound alarm bells. “I don’t think it’s alarmist,” he says — it’s reality. “There’s been a reduction in heart disease,” he says, suggesting that if heart disease isn’t allowed to set in, cancer invariably will.
Dr. Miller says cancers are being increasingly diagnosed because they’re being discovered — the result of physicians prescribing more diagnostic tests. Tests often pick up incidental cancers, which may not have acted aggressively or spread. But because they have been found, and doctors can’t predict how they will behave, they are treated.
What’s encouraging, he says, is that survival of many cancer patients is increasing, as they’re being found at earlier stages and treated with ever-evolving treatments.
The power of prevention also shouldn’t be underestimated. “There’s a lot we can do to prevent cancer,” says Dr. Smith, such as not smoking, eating healthy, exercising, maintaining a healthy weight and limiting alcohol. “Canadians need to act on this knowledge.”
CERTAIN CANCERS ARE ON THE RISE
While the news on the cancer front is generally encouraging, there are several cancers that are increasing in incidence — particularly among younger Canadians. While this is occurring for myriad reasons, it’s a trend that warrants attention, say experts.
Three cancers that have seen significant increases in diagnosis are thyroid, colorectal and uterine. Here’s what you need to know to protect yourself.
“There’s been a dramatic increase in thyroid cancer rates,” says Dr. Smith.
Between 1970 and 2017, thyroid cancer incidence rates increased in women from 3.9 to 23.4 per 100, 000 and in men from 1.5 to 7.2 per 100 000 while mortality rates have remained stable at around 0.5 per 100, 000 for both sexes, according to a 2017 study in The Canadian Medical
Association Journal. The biggest surge was seen in women aged 40–60 years, though it is the most commonly diagnosed cancer in people aged 15–29.
Dr. Sam Wiseman, associate professor in the Department of Surgery at the University of British Columbia, attending surgeon St. Paul's Hospital and director of research in the Department of Surgery at Providence Health Care in Vancouver, says the surge in diagnoses are believed to be related to more incidental pickups caused by an increase in imaging and the availability and utilization of neck ultrasounds. Dietary and environmental factors aren’t out of the question either. Exposure to radiation, certain genetic conditions, a family history of thyroid cancer, obesity, certain benign thyroid conditions and being tall are all risk factors.
He says that with the use of sophisticated and commonly-used imaging, such as CT, MRI and PET scans, the nodules are found during scans for other health investigations — as in Kruse’s case. “There’s increased detection of these cancers — many of which, though not all, would have remained clinically insignificant in a person’s life.” Dr. Wiseman says that most nodules (95 percent) are benign and even if cancer is diagnosed — be it papillary carcinoma or follicular carcinoma — survival rates are high. “The vast majority of thyroid cancers have an excellent prognosis.” He says that more lethal forms do exist but are rare. These include poorly differentiated carcinoma, anaplastic carcinoma, and medullary carcinoma.
According to Dr. Wiseman, aggressive treatment is now weighed more carefully than in the past. If a nodule is found that’s less than a centimeter in size, active surveillance is recommended. “Follow-up with ultrasound is an option for those people,” he says. For cancers, patients generally need a portion, or all of, their thyroid gland removed — and may also need additional treatment with radioactive iodine. “It hinges upon the characteristics of the patient’s tumour,” he says.
The best news is that despite the steady increase in diagnoses, “overall mortality has remained unchanged,” says Dr. Wiseman. Net survival for thyroid cancer at five years is 98%, according to the Canadian Cancer Society. And survival rates are higher for those diagnosed under age 40.
Regardless, if someone finds a lump or swelling in the neck, notices hoarseness or other voice changes, has difficulty swallowing or breathing, experiences a sore throat or cough that doesn’t go away, or has a persistent pain in the front of the neck, they should see their doctor.
First the good news: “Colon cancer is very rare under the age of 50,” says Dr. Prithwish De, director of Surveillance and Cancer Registry, Cancer Care Ontario (CCO).
That said, when CCO researchers looked at national data on colorectal cancer from the mid 1990s until 2010, they discovered that the biggest increases were among those aged 15–29. “There was about a 7% increase per year [in incidence] from the mid 1990s to 2010,” says Dr. De. Perplexed, the researchers looked at other trends in this demographic. “A 7 percent increase is quite large, says Dr. De. “We tried to explain that looking at the lifestyle risk factors.”
However, Dr. De says that most risk factors for colon cancer — inactivity, a diet high in red meat and little fibre, smoking and drinking — were not suspected as drivers of the spike in these colon cancer cases, since there hadn't been a notable increase in the prevalence of these risks for that age group. “Food and vegetable intake has been going up, people have become more physically active, alcohol intake hasn’t changed much and smoking has been decreasing in all age groups,” says Dr. De. Instead, the team focused on body mass. “The one that stood out in terms of significant increases was obesity,” he says.
Dr. De says scientists are now looking at how diet and body weight affect the development of colon cancer.
In the meantime, he suggests minimizing the risk of colon cancer, and monitoring symptoms such as a change in bowel habits, blood in stool, abdominal pain, excessive gassiness, or narrower stool. He also suggests younger patients with these symptoms take action. “Doctors don’t tend to consider cancer among young people very often,” he says. “They should be more vigilant.”
Uterine cancer diagnoses are on the rise. It was the most commonly diagnosed reproductive system cancer in 2010, with a rate of 30.3 new cases per 100 000 women, according to Statistics Canada. That incidence represented the highest rate of uterine cancer since 1992.
There are two main types of uterine cancer. Endometrial carcinoma, which starts from cells in the lining of the uterus (called the endometrium), is the most common form of this cancer. There are also uterine sarcoma, which develops in the supporting tissues of the uterus, and carcinosarcoma, which sometimes develops in the uterus.
What’s driving the increase in diagnoses? Dr. Lilian Gien, a gynecologic oncologist at the Odette Cancer Centre, Sunnybrook Health Sciences Centre, says that obesity may play a part. “There’s an increase in the rate of obesity.” When you have a lot of extra body fat, that extra estrogen can change the lining of the uterus, she says.
It’s for that reason that most cases of uterine cancer are diagnosed in women who are in menopause. The median age group of patients with endometrial carcinoma is 61 years with 75–80 percent being post-menopausal. Only 3–5 percent of women who develop it are under 40.
Risk factors include having Lynch Syndrome, a genetic condition that also increases the risk of colorectal and stomach cancers, being overweight, having abnormal periods and being diabetic, says Dr. Gien.
She says having irregular periods means that the lining of the uterus is not shedding each month. If this occurs, taking low-dose contraceptives can make you have more regular periods and reduce the risk of developing endometrial cancer. A hormone-releasing IUD can also help thin the lining of the uterus and prevent it from turning into cancer, she says. For women who do develop uterine cancer, survival rates are high: 84 percent of those diagnosed will survive for at least five years.
“Don’t think that there’s nothing you can do about it,” says Dr. Gien.
“DESPITE THE STEADY INCREASE IN DIAGNOSES, ‘OVERALL MORTALITY HAS REMAINED UNCHANGED.’”