Does Preoperative Chemoradiation Therapy in Locally Advanced Rectal Cancer Increase Rate of Sphincter Preserving Surgery? A Prospective Clinical Trial

• Main Authors: Wiroon Boonnuch, Vitoon Chinswangwatanakul, Asada Methasate, Thawatchai Akaraviputh, Varut Lohsiriwat, Darin Lohsiriwat
• Format: Article
• Language: English
• Published: Mahidol University 2006-04-01
• Series: Siriraj Medical Journal
• Subjects: Sphinctor preservation; Preoperative chemoradiation; Locally advanced rectal cancer
• Online Access: https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245754

Objective: To evaluate the influence of preoperative chemoradiation in locally advanced rectal cancer on ability to perform sphincter preserving surgery. Methods: Between 1998 and 2005, a prospective clinical trial of preoperative chemoradiation therapy (CTX/XRT) that delivered 45 Gy in 25 fractions over 5 weeks with bolus infusion of 5-fluorouracil (200 mg/m2/day) or capecitabine (2000 mg/m2/day) was given to 42 rectal cancer patients admitted to the Department of Surgery, Siriraj Hospital, Bangkok, Thailand. The pretreatment stage distribution, as determined by endorectal ultrasonography and computed tomography of the pelvis, included uT3N0 in 90.48% and uT3N1 in 9.52% of cases. Approximately 6 weeks after completion of CTX/XRT, surgery was performed in every patient. The choice of the surgical procedure was based on the surgeonus discretion. Results: The patient population consisted of 25 males (59.52%) and 17 females (40.48%) who had a median age of 57 years (range 32-79 years). Distal border of the tumors were located at a median of 5 cm (range 2-10 cm) above the anal verge. Thirty cases (71.43%) had distal border of the tumors within 6 cm from the anal verge. The pathological tumor stages were T1N0 in 2 cases (4.76%), T2N0 in 9 cases (21.43%), T2N1 in 4 cases (9.52%), T3N0 in 12 cases (28.57%), T3N1 in 8 cases (19.05%), T3N2 in 2 cases (4.76%) and T4N0 in 1 case (2.38%). The results included 9.52% pathological complete response, 42.86% downstaging and 50% sphincter preservation rate. Of the tumors located < 6 cm from the anal verge, sphincter preservation was accomplished in 30% of the patients. The pretreatment location of distal border of the tumors (< 6 cm vs. > 6 cm from anal verge) was the only factor predictive of sphincter preservation (p < 0.001). No local recurrence was detected during the period of follow up (median 23 months). Conclusion: The administration of preoperative chemoradiation for locally advanced rectal cancer is associated with tolerable toxicity and high rates of tumor downstaging. The preoperative chemoradiation and tumor downstaging do not increase rate of sphincter preservation in locally advanced rectal cancer.