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Colorectal cancer, or colon cancer as it's more commonly referred to, is one of the most commonly diagnosed cancers in Canada, and yet, it's one of the least talked about.
According to Canadian Cancer Statistics, approximately one in 14 men will be diagnosed with colorectal cancer in their lifetimes, alongside one in every 18 women.
If caught in its early stages, colorectal cancer is 90 per cent curable. What are the signs and symptoms of the disease and when should you get screened? Here's what you need to know.
What is colorectal cancer?
Colorectal cancer is a disease that affects your large intestine (colon) or your rectum (the end of the colon).
Colon and rectal cancers are grouped together as colorectal cancer because the two organs are made of the same tissues without a distinct border between them.
When cells in the colon or rectum no longer grow or behave normally, the changes may lead to non-cancerous tumours, precancerous conditions (i.e. adenomas) or colorectal cancer.
Colorectal cancer can affect anyone at any age —"Black Panther" actor Chadwick Boseman passed away from the disease at age 43. However, 93 per cent of cases in Canada occur in adults aged 50 and over.
What are the warning signs and symptoms of colon cancer?
Colorectal cancer may not present any significant signs or symptoms in its early stages, making it all the more important to stay up-to-date on your colon health and get screened regularly.
According to the American Cancer Society, a polyp can take as long as 10 to 15 years to develop into cancer. Therefore, symptoms often only start appearing once a tumour grows and affects the surrounding organs and tissues. The early signs of colorectal cancer are often similar to other health conditions, including anemia and irritable bowel syndrome.
Dr. Monika Krzyzanowska, a medical oncologist at the Princess Margaret Cancer Centre, says one of the early signs of the disease is a change in bowel habits.
"[People] may not be going as often [to the bathroom] as they usually do," she tells Yahoo Canada over the phone. "The calibre of your stool may change. For example, it can become thinner or more narrow."
Krzyzanowska notes that abdominal pain, bleeding and unexplained weight loss are causes for concern, alongside iron-deficiency anemia.
"One of the things people may not know [to pay attention to] is iron-deficiency anemia," she says. "They may be feeling tired, go see their family doctor, and are found to be anemic. This can sometimes be an initial presentation of colon cancer."
Other signs or symptoms of colorectal cancer may include:
Narrow stool (compared to average)
Blood in the stool
Unexplained weight loss
Abdominal cramps and pain
Nausea and vomiting
Pain or discomfort in the rectum
Bleeding from the rectum
Krzyzanowska says the urgent symptoms you should never ignore are "any sort of severe abdominal pain or abdominal pain associated with nausea, vomiting and an inability to pass stool," as they could be symptoms of a bowel obstruction.
Who is at risk for colon cancer?
Colorectal cancer can affect anyone, but people living with inflammatory bowel disease (Crohn’s disease and ulcerative colitis) are at an increased risk compared to the general population.
The average age of a colorectal cancer diagnosis is in people aged 50 and over, with the risk increasing with age.
Risk factors include a family history of polyps and colon cancer, obesity, smoking, alcohol, sedentary behaviour and a diet high in processed and red meat.
"Ironically, a lot of the lifestyle factors [that are good for colon health] are good for other things as well," says Krzyzanowska. "Having a healthy diet, not smoking and having a good weight" can decrease your risk of the disease.
Should you get screened for colon cancer?
Short answer: yes.
While Kristen Bell recently shared that she had an elective colonoscopy at age 41, in Canada, screening for colorectal cancer is recommended for average-risk adults aged 50 to 74 years with a stool test. If you're at higher risk, your doctor may suggest to begin screening early.
While a stool test is no one's idea of a good time, it saves thousands of lives every year.
"Colon cancer is one of the few cancers that we do have an effective screening test," says Krzyzanowska. "The evidence is quite strong that screening for colon cancer can decrease the incident [rate] and increases survival, so if you're in the right age group, go ahead and get screened."
Similar to cervical cancer screening, screening for colorectal cancer looks to find and identify polyps before they ever become cancerous.
"If you're picking up a polyp, and you can remove it, then you're moving the diagnosis a lot earlier in the disease course," Krzyzanowska says.
"I know it's scary to think you might have cancer, but it's better to be picked up early or at the pre-cancerous stage."
Colorectal cancer is "treatable, but you need to be availing yourself to the screening tests that are available," she says. "If you're having any kind of symptoms, seeking medical attention early" can save your life.
To learn more about colorectal cancer in Canada, see the resources below.