Preoperative radiation therapy for locally advanced rectal cancer: a comparison between two different time intervals to surgery.

Background: Although it is now considered a standard treatment to irradiate an advanced mid or low rectal tumor before surgical total mesorectal excision (TME), the optimal time interval between radiation therapy and surgery remains controversial.

Materials And Methods: Between 1995 and 2005, patients undergoing preoperative radiation therapy and TME for locally advanced mid and low rectal tumors treated in the VU Medical Center or the Zaans Medical Center were entered into this study. All patients received identical radiation treatment in the VU Medical Center and were subsequently operated on within 2 weeks in the Zaans Medical Center (SI group) and after 6-8 weeks in the VU Medical Center (LI group). Preoperative tumor staging, operative data, postoperative complications, pathology results, and follow-up were compared.

Results: The SI group (N=57) underwent surgery after a median delay of 4 days and the LI group (N=51) after 45 days. Operative data and short-term morbidity were comparable for both groups. However, significantly higher numbers of complete remissions (12 vs 0%), tumor downstaging (55 vs 26%), and less lymph-node metastases (22 vs 44%) were found in the LI group. No significant differences were found regarding local control or long-term survival after a median follow-up of 34 months.

Conclusion: Several advantages, such as complete remissions and downstaging in the LI group, do not appear to have expression in a better survival or less local recurrences after a median follow-up of 34 months. Although larger (randomized) studies will be needed for definite conclusions, this may indicate that patients can be operated on within 2 weeks after radiation therapy.