Colorectal cancer screening in women: The role of CT colonography

Colorectal cancer is a preventable disease if precursor adenomatous polyps are detected and removed early. Several screening modalities are available today; yet colorectal cancer remains the third leading cause of cancer death in women, following lung and breast cancer. Less than 40% of all women who need colorectal cancer screening have undergone recommended testing. Women are more likely than men to refuse repeat invasive screening tests. CT colonography, or virtual colonoscopy, has emerged as a potential solution to the underutilization of screening exams. This radiologic technique is a relatively new method of identifying precancerous polyps and early-stage cancers that is safe and noninvasive, It uses axial, multiplanar reformatted and endoluminal images reconstructed from volumetric CT data to examine the colon. In high-risk patient cohorts, the accuracy of CT colonography for large polyps and cancers has been shown to be high and similar to that of conventional colonoscopy. However, the accuracy of CT colonography in a screening population must be confirmed before its use as a screening tool. This article will discuss the epidemiology of colorectal cancer in women, and describe the advantages and disadvantages of the currently recommended available screening modalities. The optimal technique for performing and interpreting CT colonography will be discussed and the results of the performance studies on CT colonography will be reviewed. Finally, this article will conclude with a discussion of the future of CT colonography.