American Association for Clinical Chemistry
Better health through laboratory medicine
April 2010 Clinical Laboratory News: Colorectal Cancer Screening Still Inadequate

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April 2010: Volume 36, Number 4


Colorectal Cancer Screening Still Inadequate

Although colorectal cancer screening rates have doubled since the late 1980s, the various screening methods still are underused, according to a recent systematic review of evidence about the use and quality of colorectal cancer (CRC) screening. The report, commissioned by the Agency for Healthcare Research and Quality and prepared by the RTI International–University of North Carolina Evidence-based Practice Center, also concluded that the growth in screening can be attributed entirely to increased use of colonoscopy; screening with fecal occult blood testing (FOBT) and sigmoidoscopy declined over the same period. The investigators found no data on usage trends or the quality of fecal immunochemical testing, fecal DNA testing, or computed tomographic colonoscopy.

Factors consistently and significantly associated with reduced CRC screening include low income, lack of health insurance, and being Hispanic or Asian, among other reasons. Strategies with the most evidence of increasing the appropriate use of CRC screening methods include patient reminders, one-on-one interactions, and patient navigators to help patients obtain timely CRC screening.

While CRC screening rates generally are lower than desired, the report also found evidence of both overuse and misuse of CRC screening methods. Overuse exists in the frequency of surveillance colonoscopy after polypectomy, and in continuing to screen people older than age 85, a group guidelines recommend no longer screening. Misuse was noted in continuing to rely on in-office FOBT when the literature “is clear that home FOBT is preferable.” This practice substitutes a less effective test for a more effective one, according to the report. There also is evidence of inadequate follow-up for positive FOBT results.

The researchers pointed to multiple studies exploring the characteristics of potential new CRC tests but cautioned that while “improving screening tests is a reasonable research agenda,” these evaluations need to be balanced with more research on how to successfully implement screening methods already known to be effective.

The full report is available online.