Time to catch up on some colorectal cancer news that we might have missed.

In Nutshell News: Virtual colonoscopy works just as well for over 65′s, over-the-counter and prescription stomach acid is connected to c. difficile diarrhea, and the recession cut into colorectal cancer screening among people with health insurance.

Older adults benefit from CT Colonography

CT colonography, so-called virtual colonoscopy, uses x-ray images to look into the colon. In the National CT Colonoscopy trial it was was as good at finding large polyps and cancers as optical colonoscopy.  However, the Centers for Medicare and Medicaid Services (CMS) doesn’t cover the test, citing lack of evidence that it works for older adults.

Analyzing people 65 and older enrolled in the National Trial, researchers at the Mayo Clinic in Arizona found no significant differences between Medicare-aged people and younger participants.  CT colonoscopy was able to find large adenomas and cancers at nearly the same rate in  older and younger trial enrollees. There was also a very small difference between intermediate size polyps over 6 mm.

As might be expected, older adults had more polyps. About 7 out of 100 (6.9%) had large polyps or cancer compared to 4  out of 100 (3.7%) younger people.

C. Daniel Johnson and his team concluded,

For most measures of diagnostic performance and in most subsets, the difference between senior-aged participants and those younger than 65 years was not statistically significant.

FDA Warning: Stomach Acid Drugs Linked to C. Diff Infections

The FDA has warned proton pump inhibitors (PPIs) are associated with Clostridium difficile (C. difficile) diarrhea (CDAD). The warning includes both prescription and over-the-counter medicines to treat frequent heartburn and medical conditions including as gastroesophageal reflux disease (GERD), stomach and small intestine ulcers, and inflammation of the esophagus.

The FDA recommends that patients who are taking a PPI and develop diarrhea that doesn’t improve contact their healthcare professional.

Healthcare professionals are told:

• A diagnosis of CDAD should be considered for PPI users with diarrhea that does not improve.
• Advise patients to seek immediate care from a healthcare professional if they experience watery stool that does not go away, abdominal pain, and fever while taking PPIs.
• Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated.

Over-the-counter PPIs include Prevacid (lansoprazole), Prevacid 24hr, Prilosec (omeprazole), and Zegerid.

Additional prescription medicines are AcipHex (rabeprazole), Dexilant (dexlansoprazole), Nexium (esomeprazole), and Vimovo (esomeprazole and naproxen).

Recession Reduced Screening Colonoscopies for Insured

During the recent economic recession in the US, there were half a million fewer screening colonoscopies for patients with health insurance aged 50 to 64.  The need to share costs through deductibles and copays appears to be part of the reason.

From December 2007 through November 2009, 500,000 fewer screening colonoscopies were done for patients with commercial insurance compared to the previous two years. Health plans with out-of-pocket costs over $300 had lower screening rates both before and during the recession. The recession had a smaller impact on plans with the lowest out-of-pocket requirements.

Reporting their analysis of reports from 106 health plans, Spencer Dorn, MD, MPH, and his team at the University of North Carolina wrote,

Policies to reduce cost sharing could increase adherence to recommended preventive services such as colonoscopy examinations.

Fight Colorectal Cancer is supporting the Removing Barriers to Colorectal Cancer Screening Act of 2012 (H.R. 4120) which would change Medicare law so that seniors wouldn’t face additional copayments when polyps were removed during a screening colonoscopy.

The November issue of American Journal of Roentgenology described a program in which specially trained technicians performed computed tomography (virtual) CT colonoscopies in two Navajo Nation health centers and transmitted the tests for interpretation by radiologists hundreds of miles away at the University of Arizona Health Sciences Centers.

A retrospective review of 320 patients found that more than 90% of the tests showed adequate patient preparation and technical performance of the procedure.  Researchers did report a relatively high (54%) rate of false-positives, but “If there was any doubt, I called it positive and recommended a colonoscopy,” said Dr. Arthur Friedman, the lead radiologist for the study.

The study authors acknowledged that a better study would be a randomized trial comparing annual FOBT screening, optical and CT colonoscopy but, they noted, many residents in these and other rural areas live far from post offices or in homes lacking adequate plumbing, so compliance with fecal screening tests is poor, and there are not medical personnel to perform optical colonoscopies or sigmoidoscopies.

Source: Medscape, Oct. 29, 2010

Looking at more than 10,000 screening CT colonography or virtual colonoscopy exams, doctors found cancers in 1 in every 200 patients, but more often those cancers were not colorectal cancer, but unsuspected cancer found outside the colon.

The tests found 22 colorectal cancers (1 in every 500 patients examined) and 36 other cancers (1 in every 300 patients.)  More than half were found at an early stage I.  After an average follow-up time of 30 months, only 3 patients had died of cancer.

Renal cell cancer was the most frequent extracolonic cancer, discovered in 11 patients who didn’t have symptoms.  Eight lung cancers were also found along with six cases of non-Hodgkins lymphoma and eleven cancers in other sites.  More specific information about patients, their cancers, and their survival is part of the report in Radiology.

CT colonography allows radiologists limited views of the body outside of the colon, particularly in the pelvis, abdomen, and part of the lungs.  About 6 percent of the time, the exam leads to additional testing for other diseases, although more than half of that testing will eventually prove benign.

If polyps or suspected colorectal cancer is found during CTC screening, referrals are necessary for a traditional optical colonoscopy where polyps can be removed and biopsied.

During an exam patients are exposed to about 10 millisieverts (mSv) of radiation, about the same amount they receive from normal background radiation in three years.

In a news release from the Radiological Society of North America (RSNA), lead author Perry J. Pickhardt, M.D., professor of radiology and chief of GI Imaging, at the University of Wisconsin School of Medicine & Public Health, noted,

We are finding that virtual colonoscopy screening actually identifies more unsuspected cancers outside of the colon than within it. As with asymptomatic colorectal cancers identified by virtual colonoscopy screening, these cancers are often detected at an early, curable stage.

However, he points out that CT colonography does find benign conditions that nevertheless need follow-up.

Although extracolonic evaluation at screening CT colonography does carry some disadvantages, such as patient anxiety, inconvenience, or the potential for benign biopsy, our results suggest that early detection of asymptomatic extracolonic cancer represents an additional benefit of screening CT colonography that is not available with optical colonoscopy

Reporting their results in the April issue of Radiology, Pickhardt and his colleagues concluded,

The overall detection rate of unsuspected cancer is approximately one per 200 asymptomatic adults undergoing routine screening CT colonography, including about one invasive CRC per 500 cases and one extracolonic cancer per 300 cases. Detection and treatment at an early presymptomatic stage may have contributed to the favorable outcome.

SOURCES:  Pickhard et al., Radiology, Volume 255, Issue 1, pages 83-88, April 2010.

RSNA News Release: Virtual Colonoscopy Allows Detection of Unsuspected Cancers Beyond Colon, March 23, 2010.