"Optical colonoscopy cannot provide for any assessment beyond the colon itself, whereas virtual colonoscopy can detect a wide array of unsuspected extracolonic diseases, most notably cancers and aortic aneurysms," Dr. Pickhardt said.
For the study, Dr. Pickhardt and colleagues set out to determine the detection rate and clinical outcome of unsuspected malignancies detected with virtual colonoscopy in an asymptomatic screening population. The researchers retrospectively reviewed the medical records of 10,286 adults (5,388 men and 4,898 women) with a mean age of 59.8 years who were evaluated at either the University of Wisconsin or National Naval Medical Center. All of the adults had undergone colorectal cancer screening with virtual colonoscopy at the two centers between April 2004 and March 2008. The mean time for follow-up was 30.2 months.
Unsuspected cancer was confirmed in 58 patients, including 33 women and 25 men. Invasive colorectal cancer was found in 22 patients, and extracolonic cancer was found in 36 patients. Cancers in 31 patients (53.4 percent) were stage 1 or localized cancers.
"To our knowledge, none of the patients who presented with stage 1, stage 2 or localized disease at diagnosis has progressed to a higher stage," Dr. Pickhardt said. "The fact that so many of the cancers in our study were localized or detected at an early stage appears to have positively affected survival."
Extracolonic malignancies, which outnumbered cases of invasive colorectal cancer, included renal cell carcinoma, lung cancer and non-Hodgkin lymphoma, among others.
"Although extracolonic evaluati
|Contact: Linda Brooks|
Radiological Society of North America