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.
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.
"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 nations 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.