By Fintan Walsh, Heath Correspondent for the Limerick Leader
PEOPLE with a family history of colorectal cancer or abnormal gastrointestinal tissue growths (polyps) should be screened, according to breakthrough research co-led by University of Limerick academics.
Colorectal cancer is the second leading cause of cancer deaths in Ireland, with 20 deaths and 60 diagnoses a week. On average, one in 25 people will develop the disease throughout their lifetime.
The research, published in the world-renowned journal Gastroenterology, makes 19 recommendations which guide the choice of screening tests and the frequency of which for those who have close relatives with colon cancer or precancerous growths.
Head of the graduate entry medical school (GEMS) at UL, Prof Des Leddin was the co-lead author on the paper, working alongside eight other universities in the United States and Canada.
“The guidelines will, we hope, reduce mortality from this common disease and ensure that screening resources are optimally used. The impact of this work, which was co-led by UL, will be global in reach and will affect screening for a large segment of the population.”
Prof Leddin said that between one in 10 and one in 20 people has a relative with colon cancer and one in two people may have a relative with pre-cancerous growths.
However, Prof Leddin said that evidence-based guidelines have not previously been developed for this cohort of people.
“The purpose of this study was to correct this gap in cancer screening by carefully sifting through all of the evidence to draw up best practice guidelines for consumers and health care providers,” he said.
He said he expects UL’s research will attract “significant international interest” in its findings.
A team of experts from nine universities examined 35,000 papers over a three-year period at a cost of US$300,000.
“The takeaway from this for the general population is clear,” says Professor Leddin. “If you have a parent, a sibling or a child with colorectal cancer or certain types of precancerous tumours, you are at an increased risk of developing the disease. Talk to your family doctor about appropriate screening.”
The elevated risk associated with a family history of one or more close family members (parent, children, sibling) with bowel cancer or documented advanced polyps necessitates initiating screening at a younger age (e.g. 40-50 years or 10 years younger than age of the family member at diagnosis).
In addition, the research recommends a shorter interval of every five years between screening tests for individuals with two or more close family members with colorectal cancer, and every five to 10 years for those with a family history of one close relative with bowel cancer or documented advanced adenoma compared to average risk individuals.
The research also found that choosing screening parameters for an individual patient, should consider the age of the affected close relative, and local resources. The good news is that the risk of getting bowel cancer if the only affected family members are aunts, uncles or cousins is not much different than average and the people in this category can be screened according to average-risk guidelines.