Abstracts 1998 Digestive Disease Week
#1005
PREOPERATIVE CHEMORADIOTHERAPY PERMITS <1 CM DISTAL MARGIN AND SPHINCTER PRESERVATION FOR DISTAL RECTAL CANCER. B.W. Kuvshinoff. I. Magfoor. B. Miedema. J. Wilkes. S. Westgate, and D.M. Ota. Dept. of Surgery, University of Missouri Ellis Fischel Cancer Center and Harry S. Truman VAMC, Columbia, Missouri.
Approximately 50% of patients with newly diagnosed rectal cancer are treated with abdominoperineal resection (APR), many of out of concern for adequate distal margins. In the current study, we employed preoperative chemoradiotherapy to test the hypothesis that "downstaging" low-lying rectal cancers could allow sphincter sparing surgery (SSS) despite distal margins one centimeter or less without adversely affecting disease recurrence.
Methods: We evaluated 30 patients with clinical stage II or III distal (_8 cm from anal verge) adenocarcinomas of the rectum. Preoperative therapy consisted of 300 mg/m2/d of 5-fluorouracil (5-FU) as a continuous infusion five days per week for six weeks. Concurrent radiotherapy to the pelvis was administered to a dose of 4500 cGy in 25 fractions followed by a 900 cGy boost to the tumor in five fractions. Six weeks following completion of chemoradiotherapy patients underwent SSS or APR. Distal and radial margins were assessed to the nearest millimeter using the fixed specimens.
Results: All patients completed radiation therapy while chemotherapy was discontinued in three cases due to toxicity. SSS was successfully accomplished in 23 (76%) patients, with APR performed in the remaining 7 (24%). Perioperative morbidity occurred in 6/30 (20%) patients including an anastomotic leak, a rectovaginal fistula, and three anastomotic strictures. Three patients achieved a pathologic complete response, while 11 patients had only microscopic residual disease at surgery. The influence of distal margins after SSS on recurrence at a median follow-up of 23 months is shown below:
Group
|
Distal margin
|
Patients
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Locally recur
|
Distant recur
|
A
|
_ 10mm
|
12
|
1
|
3
|
B
|
> 10 mm or APR
|
18
|
1
|
4
|
Radial margins less than 1mm were documented in one patient from group A and three patients from group B. Pathologic lymph nodes were demonstrated in six patients from group A and five patients from group B.
Conclusions: Preoperative chemoradiotherapy for distal rectal cancer is well tolerated and allows sphincter preservation in a majority of patients who might otherwise require an APR. Successful sphincter preservation often resulted in distal margins less than 1 cm, yet did not adversely affect either local or distant disease recurrence. Selective use of preoperative chemoradio-therapy appears to improve sphincter preservation without compromising oncologic efficacy.
Copyright 1996 - 1998, SSAT, Inc. Revised 29 June 1998.
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