Single flexible sigmoidoscopy screening associated with reduced colorectal cancer

August 18, 2011

A single flexible sigmoidoscopy screening between the ages of 55-64 years is associated with a lower level of colorectal cancer (CRC) incidence and mortality, according to a study published online August 18 in the Journal of the National Cancer Institute.

Multiple have shown that fecal (FOBT) in CRC screening can reduce the rate of patients diagnosed with CRC. Observational studies and a prior, randomized trial from the U.K., known as SCORE have shown a reduction in incidence and mortality for cancer in the rectum and sigmoid colon (distal CRC) among patients who had undergone endoscopy, suggesting that the removal of at screening can provide long-term protection against the development of distal CRC.

To determine if single is a good preventative measure in CRC screening, the researchers, coordinated by Nereo Segnan, M.D., of the Epidemiology Unit at S. Giovanni University Hospital in Turin, Italy, mailed a questionnaire investigating about subject's interest in FS screening to a random population sample of men and women between the ages of 55-64 years. Eligible interested responders were randomly assigned to either the control group (N= 17148 - no further contact) or intervention group (N=17144 - invitation for flexible sigmoidoscopy)

Flexible sigmoidoscopy was performed on 9,911 subjects, and of those, 9,387 (94.71%) were discharged, 55 (0.55%) were referred for surgery, 395 for follow-up surveillance colonoscopy, and the remaining 74 patients did not comply with the recommended total colonoscopy assessment.

The median follow-up period was 10.5 years for CRC incidence and 11.4 years for all-cause and CRC-specific mortality. During this period 557 people (including those detected at initial screening) were diagnosed with a CRC and 148 died of the disease.

The researchers found that in the intent-to-treat analysis, CRC incidence and mortality were reduced by 18% and 22%, respectively. CRC incidence was reduced by 31% among those who were screened (per –protocol analysis), and by 46% for advanced CRC cases.

Furthermore, CRC mortality was statistically significantly reduced by 38% in screened subjects compared to the control group.

The authors write that the reported findings, which are consistent with the observed reduction of CRC incidence and mortality among people screened in the recently published UK Flexible Sigmoidoscopy Screening Trial, support the hypothesis that "Flexible sigmoidoscopy screening offered just once represents a safe and effective method for CRC screening and ensures a long lasting reduction of CRC risk." According to the researchers, "A longer follow-up is needed to fully assess the impact on mortality and to estimate the duration of the protective effect."

In an accompanying editorial, Timothy R. Church, Ph.D., of the University of Minnesota, writes about what the best approach to CRC screenings may be. Underlying the three main CRC tests (flexible sigmoidoscopy, FOBT, and ), Church mentions that a cost-effective analysis is an important factor in determining the best available method, stating, "these costs are driven by not only the up-front infrastructure costs for laboratories, equipment, endoscopy facilities, training, and manufacturing but also by the rates of false-positive results."

Church argues that since none of the standard three approaches to CRC screening is more effective than the other, until more substantial evidence is collected, endorsing all three methods is the best way to attack CRC. In the event of conflicting results from the tests, Church writes: "Any concerns about the potential confusion that arises from multiple approaches may be balanced by the advantages of tailoring screening to the preferences of the patient."

Explore further: Patient navigators appear to improve colorectal cancer screening rate in ethnically diverse patients

Related Stories

Patient navigators appear to improve colorectal cancer screening rate in ethnically diverse patients

May 23, 2011
Among low-income patients who are black or whose primary language is not English, patient navigators may help improve colorectal cancer (CRC) screening rates, according to a report in the May 23 issue of Archives of Internal ...

Recommended for you

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

Discovery could lead to better results for patients undergoing radiation

July 19, 2017
More than half of cancer patients undergo radiotherapy, in which high doses of radiation are aimed at diseased tissue to kill cancer cells. But due to a phenomenon known as radiation-induced bystander effect (RIBE), in which ...

Definitive genomic study reveals alterations driving most medulloblastoma brain tumors

July 19, 2017
The most comprehensive analysis yet of medulloblastoma has identified genomic changes responsible for more than 75 percent of the brain tumors, including two new suspected cancer genes that were found exclusively in the least ...

Novel CRISPR-Cas9 screening enables discovery of new targets to aid cancer immunotherapy

July 19, 2017
A novel screening method developed by a team at Dana-Farber/Boston Children's Cancer and Blood Disorders Center—using CRISPR-Cas9 genome editing technology to test the function of thousands of tumor genes in mice—has ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.