Computed Tomographic Colonography offers Effective Colorectal Cancer Screening

Colorectal Cancer

Colorectal cancer is the third most frequently diagnosed cancer and second leading cause of cancer death in men and women in the United States. Each year nearly 50,000 Americans die from colorectal cancer.  Virtual colonoscopy or computed tomographic colography is a technique which  provides a computer-simulated endoluminal perspective of the air-filled distended colon. Recently researchers at the University of Wisconsin School of Medicine and Public Health revealed that Computed tomographic colonography (CTC) is  very effective in screening older patients for colorectal cancer (CRC).

The technique uses conventional spiral or helical CT scan or magnetic resonance images acquired as an uninterrupted volume of data, and employs sophisticated postprocessing software to generate images which allow the operator to fly-through and navigate a cleansed colon in any chosen direction.  CT colonography uses CT scanning to obtain an interior view of the colon (the large intestine) that is otherwise only seen with a more invasive procedure where an endoscope is inserted into the rectum.  For this study, the team examined various various CTC performance and program outcome measures for screening individuals aged 65-79.  The results corroborate that CTC is safe and effective  in screening of colorectal cancer.  In the study, for this older screening group, the advanced neoplastic prevalence was 7.6 percent (44 of 577). The overall referral rate to optical colonoscopy of 15.3 percent (88 of 577) is actually slightly lower than other Medicare covered CRC screening exams such as flexible sigmoidoscopy. Potentially important extracolonic findings were seen in 15.4 percent (89 of 577), with a work-up rate of 7.8 percent (45 of 577). The majority of important extracolonic diagnoses were vascular aneurysms (n = 18). No major complications were encountered.

“This study shows that CTC is a viable screening exam in all age groups. We are hopeful, now that the remaining questions regarding older patients have been answered, patients will have wider access to the CTC, more will be screened for colorectal cancer, and more lives can be saved as a result,” said David H. Kim, MD, associate professor of radiology, University of Wisconsin School of Medicine and Public Health, and principal investigator of the study.