BOSTONPreoperative CT scans may be a cost-effective way to
improve management of colon cancer patients through earlier
identification of those who have liver metastases, Richard S.
Swanson, MD, said at the American Society of Colon and Rectal
Surgeons (ASCRS) annual meeting.
He presented a retrospective study in which a significant number of
patients with potentially resectable colon cancer could have been
upstaged from M0 to M1 on the basis of their CT scans. If all the
scans had been done preoperatively, approximately 1 in 20 patients
would have had liver metastasis detected in time for doctors to do a
combined colon and liver resection.
Dr. Swanson and his co-authors at University of Massachusetts
Memorial Health Care, Worcester, estimated the potential cost saving
could translate to $850 per patient if all colon cancer patients had
a preoperative CT scan.
In a postconference interview with ONI, Dr. Swanson, chief of
surgical oncology at the hospital, stressed that the study was not
conclusive, but a what if examination raising questions
for further study. The point of this is a hypothesis. Possibly
we could save money and improve care. It needs to be tested, he
said, noting that he is trying to set up a prospective study.
The retrospective study was designed to address a controversial
recommendation that a National Institutes of Health Consensus
Conference published 10 years ago (JAMA 264:1444, 1990). The
conference recommended that all colon cancer patients have a CT scan
of the abdomen for disease staging.
The conference was criticized at the time, Dr. Swanson said, for not
having enough data to make the recommendation, and many surgeons
still wonder whether a preoperative CT scan is more useful than one
done after surgery.
Stymied by the continuing lack of data, the Massachusetts group
decided to see what the hospitals experience had been and might
have been. It reviewed 190 consecutive patients diagnosed with
potentially resectable colon cancer from 1988 to 1997. Of these, it
found 123 who had CT scans either before surgery or within 2 months
after colon resection.
Twenty-one (17%) of the 123 patients were found to have liver
metastases on their CT scans. These patients included 1 (14%) who was
upstaged from stage I to stage IV, 5 (10%) upstaged from stage II to
stage IV, and 15 (23%) who went from stage III to stage IV. This led
the researchers to conclude that a CT scan can upstage 10% to 23% of
all patients with potentially resectable colon cancers.
Six (4.9%) of the scanned patients had resectable liver metastases
and thus could possibly have had a combined colon and liver resection
if their CT scans had been done preoperatively.
This is a hypothesis that needs to be tested, Dr. Swanson
said. There could be other financial costs. Other factors might
come into play that might negate the cost benefits to the patient.
For example, if morbidity of doing combined surgery is significant,
that might translate into complications and more postoperative care.
The issue is important, he added, because pending more data to back
up the CT scan recommendation, some surgeons do not order a CT scan
for patients with early-stage colon cancer unless they see a pattern
that suggests metastasis. In the majority of cases, patients do
get a CT scan now, he said, but its not an absolute.