Purpose: To evaluate the impact of preoperative external radiation therapy intensified by systemic chemotherapy including bolus cisplatin (c-DDP) and 4-day infusional 5-fluorouracil (PLAFUR-4) on tumor response and sphincter preservation in patients with extraperitoneal T3 rectal cancer with acceptable toxicity, and to compare the results to our previous experience with bolus mitomycin c (MMC) and 4-day infusion 5-FU (FUMIR).
Methods and materials: Between October 1995 and March 1998, 40 consecutive patients with resectable extraperitoneal adenocarcinoma of the rectum were treated with preoperative chemoradiation: slow infusion i.v. c-DDP, 60 mg/m2, day 1 and 29 plus 24-h continuous infusion i.v. 5-fluorouracil (5-FU) 1000 mg/m2, days 1-4 and 29-32, and concurrent external beam radiotherapy (45 Gy whole pelvis followed by 5.4 Gy boost). All but 3 patients had T3 disease. Surgery was performed 6-8 weeks after the end of chemoradiation.
Results: No patient had Grade 4 acute toxicity. Grade 3 hematological toxicity was observed only in 2 (5%) patients. No patient had major gastrointestinal, skin, or urological acute toxicity. All patients had radical surgery. There was no perioperative mortality; perioperative morbidity rate was 12%. Overall, 23% (9 of 40) of patients had a complete pathological response and 10% (4 of 40) of patients had rare isolated residual cancer cells (Tmic). Comparing the stage at the diagnostic workup with the pathological stage, tumor downstaging was observed in 27 (68%) patients; nodal status downstaging was detected in 24 (60%) patients. Thirty-four (85%) patients had a sphincter-saving surgical procedure. In 4 of 10 (40%) patients who were definitive candidates for an abdominoperineal resection (APR), the sphincter was preserved, as it was in 13 of 13 (100%) probable candidates. Lengthening of the distance between the anorectal ring and the lower pole of the tumor > or =20 mm was observed in 9 (23%) patients. None of the patients had soilage after the sphincter-saving procedure. In our previous experience with FUMIR the complete pathological response was 9%, the sphincter-saving surgical procedure was performed in 66% cases, and the Grade 3+ toxicity was observed in 13% of patients.
Conclusions: The addition of c-DDP to 5-FU (PLAFUR-4) in a neoadjuvant radiochemotherapy schedule improved the pathological response rate in comparison with our previous experience. Toxicity was low indeed, thus we commenced another study adding one more day of 5-FU infusion (PLAFUR-5) to further improve our results.