Cancer tests at home

It might not be pleasant, but it could save your life. A new Canadian campaign advocating home screening for colorectal cancer could reduce deaths from the disease by catching it early, when it is often asymptomatic but also highly curable.

The Canadian province of Ontario has one of the world's highest rates of colorectal cancer, according to the provincial health ministry, and it's the second deadliest cancer in the province. The disease has a 90-percent cure rate when caught during its early stages, but because the cancer is often asymptomatic until it is further progressed, it can be missed.

About 40 percent of the 20 000 Ontarians diagnosed with colon cancer each year will die, said Dr Philip Branton, scientific director of the Canadian Health Research Institute, in a release.

The Ontario provincial government recently began promoting home faecal occult tests, a screening tool that tests for blood in the stool, an early but often missed symptom of colorectal cancer.

Remarkable results
A similar screening programme introduced in parts of the UK halved the number of hospital admissions and deaths from colon cancer in those areas within five years, a study published in the journal Gut showed.

And last week, researchers detailed in the British Medical Journal how a national Finnish colon cancer screening program involving faecal analysis caught 40 percent of colon cancers early.

The term colorectal cancer refers to both cancer of the colon and cancer of the rectum. According to the Canadian Cancer Society, symptoms include changes in bowel habits, bright red or very dark blood in the stool, diarrhoea or constipation, narrowed stools, abdominal discomfort, unexplained weight loss, exhaustion and vomiting.

The death rate from colorectal cancer has been dropping over the past few years, partly due to a decrease in the number of cases, according to the American Cancer Society, but also because of the growing use of screening programmes that help to catch the disease early.

How the test works
Faecal occult tests can be self-administered at home. It involves collecting a small stool sample on three different days and testing for the presence of blood. Blood in the stool does not usually mean that you have cancer - only about 10 percent of people with a positive faecal occult test are later found to have colorectal cancer, according to Ontario's Ministry of Health and Long-Term Care. But it is one of the symptoms, and the faecal occult test can detect the presence of blood before it's visible to the eye.

If the test detects blood in the stool, a follow-up test like a colonoscopy is used to check for colon polyps, or growths, or cancer. The exam is recommended biannually for those over 50, or for those with an increased risk of colon cancer, such as people with a first-degree relative who has had the disease, or who have had a faecal occult test come back positive.

Studies have shown that the death rate from colorectal cancer is reduced by 16 percent over a decade when colonoscopies are done every two years, according to Ontario's provincial health ministry. – (Reuters Health)

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Cancer Centre

December 2008