News at Medicine - February 2020 - New research in colon cancer screening

New research in colon cancer screening
February 4, 2020
Like all resident doctors, Dr. David McComiskey had to choose a research project to do as part of his medical training. Dr. McComiskey chose colorectal cancer screening and the results of his study could have a big impact on people in this province.
Newfoundland and Labrador has the highest rate of colorectal cancer in the country. In fact, last year NL had about 650 new diagnosis and 270 deaths from the disease.
What Dr. McComiskey’s random research project discovered turns out to be very good news for many people in this province who go through regular screening.
His study concluded that a simple three minute scan, or computed tomography colonography (CTC), was just as effective at detecting cancer in the colon as a colonoscopy; a procedure with a long waitlist and dreaded by most people. The study also showed that people could wait more like seven years between screenings instead of the five years currently recommended.
A native of Stephenville, NL Dr. McComiskey also has a masters in human genetics and is in his final year of a five year radiology residency. He explained that Newfoundland is very rare when it comes to research like this because it is a founder population with an extremely high rate of the disease. In addition, Newfoundand and Labrador has MEDITECH, a patient index used across the province.
“All the patients in Newfoundland are under this one system so if you’re a doctor in Stephenville or St. John’s you can access any patient’s medical records. That’s not the case in most places in the world.”
Both high and low risk patients with negative CTC screening in the Eastern Health Region were included in his study. Dr. McComiskey also cross referenced his data with the NL Cancer Care Registry, a population-based registry that collects, uses and shares health information related to cancer screening and care in the province.
Waitlists for CTC are a lot shorter, mainly because it’s a relatively new screening method. But, as Dr. McComiskey points out, it means you don’t have to go through the long waitlist of colonoscopy. “You can get a CTC in a couple of weeks. It also means if you’re scared of the potential complications of a colonoscopy like perforating your bowel, those complications don’t exist with CT colonography. And some people can’t tolerate the colonoscopy so they refuse it but now they have this alternative.”
Dr. McComiskey does admit there is a trade-off. “The advantage to the colonoscopy is that if they see something on the bowel they can snip it out if it’s small whereas with the CTC version, they’ll see it but then a colonoscopy has to be performed to remove it.”
He says the findings on effectiveness didn’t surprise him. “The technology is getting so advanced with imaging that we are able to see more and more. There is the single study radiation dose associated with a CT, but there's also avoiding the risk of a bowel perforation or other rare complications seen with colonoscopy. All of these risks are abstract and rare, but when you do a direct comparison that's the sort of things we look at.”
He was, however, surprised at the second conclusion. “That the interval screening length for CTC could be so long, up to seven years instead of the currently held five. A follow-up study will be doing it after 10 years. It will be fun to see those results.”
“I am glad I could make that impact, any significant impact. Ultimately physicians just want to help people, and I hope these results can help to put CTC on the map more locally and also internationally as a perfectly viable option for those unable to tolerate a colonoscopy.”
Colorectal Cancer Outcomes in a Large Negative Computed Tomography Colonography Screening Cohort, was published in the Canadian Association of Radiologists Journal in 2019. Also authors on the study were Dr. Brendan Barrett, Dr. Jeffrey Fleming and Dr. Eric Sala, also from the Faculty of Medicine, as well as and Kathy McKay.
Dr. McComisky received the following awards for the study:
  • The Newfoundland & Labrador Annual Radiology Research Symposium Top Resident Award in 2018.
  • The European Society of Gastrointestinal and Abdominal Radiology International Top 20 Presenter in when he presented in Prague, Czech Republic in 2016.
  • The Canadian Society for Clinical Investigation CIHR National Resident Research Prize in 2016; and
  • The Newfoundland & Labrador Association of Radiology Top Junior Resident Research Prize in 2016.