Featured Research

from universities, journals, and other organizations

Colonoscopy isn't perfect: About six percent of colorectal cancers are missed

Date:
March 20, 2014
Source:
University of Utah Health Sciences
Summary:
About six percent of colorectal cancers are diagnosed within three to five years after the patient receives a clean colonoscopy report, according to a population-based study. These cancers may have been overlooked at the time of colonoscopy or developed rapidly during the window between colonoscopies and are therefore referred to as "missed" colorectal cancers.

About 6 percent of colorectal cancers are diagnosed within three to five years after the patient receives a clean colonoscopy report, according to a population-based study by researchers from Huntsman Cancer Institute (HCI) at the University of Utah.

These cancers may have been overlooked at the time of colonoscopy or developed rapidly during the window between colonoscopies and are therefore referred to as "missed" colorectal cancers. The three- to five-year timeframe is well inside the ten years recommended between colonoscopies for colorectal cancer screening in the general public, as well as the five years indicated for people at increased risk.

The research results were published online in the journal Gastroenterology.

"Not only did we find that colonoscopy isn't perfect, we discovered a number of factors associated with these 'missed' cancers," said N. Jewel Samadder, MD, M.Sc., lead author of the study and an HCI investigator. "They tended to appear in patients over the age of 65, patients with a family history of colorectal cancer, and patients in whom polyps were previously found."

The missed cancers were also more likely to appear in the right side of the colon, at the far end of the colonoscope's reach. "Our first thought was that perhaps doctors did not view the entire colon, or that preparation for the procedure was not complete, which would obscure their view," said Samadder. "However, the medical records of the patients with missed cancers showed these problems were seldom present."

The study integrated information about colonoscopies performed at Intermountain Healthcare (IHC) and University of Utah Health Care (UUHC) over the 14-year period between 1995 and 2009. Taken together, the IHC and UUHC systems provide care to more than 85% of Utah's population. The researchers also used the Utah Population Database (UPDB), which combines genealogical, medical, and demographic data with cancer records from the Utah Cancer Registry, which allowed them to count patients who developed colorectal cancer and those who had a family history of the disease while keeping their identities confidential.

While the term 'missed' may indicate that cancer or precancerous polyps were present but not seen, the category also includes cancers that had no visible evidence at the time of colonoscopy but developed rapidly afterward. According to Samadder, "Cancers in the right side are often biologically different than those in other parts of the colon, arising from different types of polyps. These types of polyps are flatter and faster growing, which may explain why they are not seen during colonoscopy as well as how a cancer could develop even when no polyps were visible."

The study showed that in the United States the rate of cancers missed at colonoscopy is only slightly lower than in Germany and Canada where similar studies have been conducted. In the U.S., most colonoscopies are performed by gastroenterologists who receive extensive training in the procedure. Previously, American physicians had assumed that the missed cancer rate would be much lower in the U.S., because many colonoscopies in the foreign health care systems are performed by family physicians, internists, and surgeons who may not be as well trained in the procedure. According to Samadder, physicians and patients need to communicate prior to the procedure to ensure that a complete medical history, accounting for older age, family history of colorectal cancer, and prior history of polyps, is known so extra time and care can be taken during the procedure, especially on the right side of the colon.

Many organizations, such as the American Society of Gastroenterologists (ASGE), now recommend that physicians spend at least 6-10 minutes closely examining the colon lining for polyps during the procedure's withdrawal phase (where they have reached the end of the colon and are beginning to come out).

"This is not entirely a quality of care issue," Samadder said. "Our findings implicate genetic and biological issues associated with having previous polyps and having a family history of colorectal cancer."

Samadder's research team currently has funding from the American College of Gastroenterology (ACG) to analyze various genetic elements of tumor tissues from missed cancers to search out their molecular signatures and determine how they differ from cancers detected during colonoscopy. "Only by understanding the limitations of colonoscopy," Samadder said, "can we improve its use and ability to detect polyps and thereby reduce the burden of colorectal cancer."


Story Source:

The above story is based on materials provided by University of Utah Health Sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. N. Jewel Samadder, Karen Curtin, Thérèse M.F. Tuohy, Lisa Pappas, Ken Boucher, Dawn Provenzale, Kerry G. Rowe, Geraldine P. Mineau, Ken Smith, Richard Pimentel, Anne C. Kirchhoff, Randall W. Burt. Characteristics of Missed or Interval Colorectal Cancer and Patient Survival: A Population-Based Study. Gastroenterology, 2014; 146 (4): 950 DOI: 10.1053/j.gastro.2014.01.013

Cite This Page:

University of Utah Health Sciences. "Colonoscopy isn't perfect: About six percent of colorectal cancers are missed." ScienceDaily. ScienceDaily, 20 March 2014. <www.sciencedaily.com/releases/2014/03/140320173512.htm>.
University of Utah Health Sciences. (2014, March 20). Colonoscopy isn't perfect: About six percent of colorectal cancers are missed. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2014/03/140320173512.htm
University of Utah Health Sciences. "Colonoscopy isn't perfect: About six percent of colorectal cancers are missed." ScienceDaily. www.sciencedaily.com/releases/2014/03/140320173512.htm (accessed August 27, 2014).

Share This




More Health & Medicine News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WHO Calls for Ban on E-Cigarette Sales to Minors

WHO Calls for Ban on E-Cigarette Sales to Minors

AFP (Aug. 26, 2014) — The World Health Organization called Tuesday on governments should ban the sale of e-cigarettes to minors, warning that they pose a "serious threat" to foetuses and young people. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Newsy (Aug. 26, 2014) — A study published in the journal "Neurology" interviewed more than 19,000 people and found 15 percent suffer from being "sleep drunk." Video provided by Newsy
Powered by NewsLook.com
Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Newsy (Aug. 26, 2014) — A new study found fewer deaths from prescription drug overdoses in states that have legalized medical marijuana. But experts disagree on the results. Video provided by Newsy
Powered by NewsLook.com
Official: British Ebola Sufferer Receiving Experimental Drug

Official: British Ebola Sufferer Receiving Experimental Drug

AFP (Aug. 26, 2014) — A British nurse infected with Ebola while working in Sierra Leone is being given the same experimental drug used on two US missionaries who have recovered for the disease, doctors in London say. Duration: 00:44 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins