Photography of the Cecum Should Accompany Colonoscopy, Say Researchers

The best deterrent against colorectal cancer may be to photograph the cecum--where a significance incidence of colorectal cancer occurs--as a complement to performing colonoscopy, according to a study conducted in Allentown, Pennsylvania. The study was presented at the 1998 Annual Meeting of the American Society of Colon and Rectal Surgeons.

Retrospective Study

Researchers reviewed records of 557 high-risk patients with confirmed diagnoses of colorectal cancer from 1989 to 1996 to identify those who were diagnosed with colorectal cancer within 5 years of having colonoscopies. Records showed that 29 patients, or 5% of the study group, had colonoscopies within 5 years of being diagnosed with colorectal cancer; on average, the colonoscopies were performed 23 months before diagnosis. Three-fourths of the 29 patients had tumors in the cecum, and most of the tumors were large and progressing aggressively when discovered.

 "These findings led us to two conclusions. Either early polyps or cancers were undetected during colon surveillance, giving patients ‘false negative’ readings,or polyps developed and grew rapidly between colonoscopies," said Lester Rosen, MD, professor of clinical surgery, College of Medicine, Pennsylvania State University, and director, Care Management Research, Lehigh Valley Hospital. "Evidence with regard to polyp size and developmental stage suggests that these cancers were undetected during earlier colon surveillance. This underscores the importance of photographing the cecum in conjunction with colonoscopy when cancer is suspected in high-risk patients."

Although colonoscopy is more accurate than x-ray in detecting polyps or early cancer, photographing the cecum is not a standard practice in the examination.

Fewer False-Negatives

"Colonoscopy is the best test for early detection of colorectal cancer; however, it is impossible to inspect every crevice and fold. We are always finding new ways to expand our detection of cancer, just as we are in mammography," Dr. Rosen added. "Since cecal cancer was most prominent in the study, photographing the cecum as a standard practice during colonoscopy will document its inspection and reduce future false negatives during colon surveillance."

High-risk patients, who would generally undergo colon surveillance, include those with a history of cancer or benign polyps; those with a parent, sibling, or child with colorectal cancer; and those who have changes in bowel habits, rectal bleeding, or other unusual symptoms, such as abdominal pain or weight loss.

Colorectal cancer--the nation’s second most deadly malignancy--strikes 165,000 Americans and Canadians annually and causes over 65,000 deaths. Ironically, it is one of the most curable cancers, particularly when disease is detected in its earliest stages. Some 80% to 90% of colon cancers detected in the earliest stages result in cure. The cure rate drops to 50% or less when the cancer is diagnosed in its later stages.