Adjuvant therapy for rectal cancer – the transatlantic view

Abstract

In North America there are two conventional treatments for clinically resectable rectal cancer. First is surgery and, if the tumour is T3 and/or N1-2, this is followed by postoperative combined modality therapy. The second, for patients with ultrasound T3 or clinical T4 disease, is pre-operative combined modality therapy followed by surgery and postoperative chemotherapy. Pre-operative therapy (most commonly combined modality therapy) has gained acceptance as a standard adjuvant therapy. The potential advantages of this approach compared with postoperative therapy include less acute toxicity and enhanced sphincter preservation. Recently completed randomized trials in the US and Germany will provide a definitive answer to this theory. In contrast to the combined modality approach to pre-operative therapy a number of European centres advocate an intensive short course of radiation (5 Gy x 5 followed one week later by surgery). The only randomized trial which has revealed a significant advantage in survival is the Swedish Rectal Cancer Trial. The Dutch CKVO 95-04 TME trial did not confirm a survival advantage and two metanalyses report conflicting results. Due to selection bias, it is not possible accurately to compare the local recurrence and survival results of intensive short course radiation with conventional pre-operative combined modality therapy. The intensive short course radiation approach is not used in North America due to its higher toxicity and lack of sphincter preservation. In the Dutch trial the 5-year local recurrence was 12% with TME and was significantly decreased to 6% with pre-operative radiation. The 5-year local recurrence rate in the 324 patients with stage III disease who underwent a TME alone with negative margins was 20%. Therefore, despite TME surgery, radiation therapy is still a necessary component in the adjuvant management of rectal cancer.

Evaluation of safety of increased time interval between chemoradiation and resection for rectal cancer

“…9 Due to higher toxicity and lack of sphincter preservation, however, intensive short course radiation has not gained favor in North America. 10 Francois et al demonstrated that, by delaying surgery for six to eight weeks after completion of radiation, versus two to three weeks after, there was a significant increase in sphincter preservation rates without an increase in complications. 11 This six-to-eightweek interval has since become part of the standard protocol for the treatment of rectal cancer.…”

Chemoradiotherapy and adjuvant chemotherapy for rectal cancer

“…Several RCTs have addressed this issue. [23][24][25][26][27][28][29][30][31][32][33][34] These trials used conventional doses and techniques of radiotherapy plus concurrent 5-fl uorouracil (5-FU)-based chemotherapy. Low accrual resulted in the early closure of two of the trials, the National Surgical Adjuvant Breast and Bowel Project Protocol (NSABP) R-03 trial and the INT 0147 trial.…”

Transanale endoskopische mikrochirurgische Exzision von pT2-Rektumkarzinomen

“…22% ihrer Patienten mit pT2-Karzinomen Lymphknotenmetastasen fanden. Daher muss vergleichbar der Behandlung von Patienten, die sich einem konventionellen Verfahren unterziehen, bei Patienten im UICC-Stadium II/III eine adjuvante Radiochemotherapie durchgeführt werden [50][51][52][53][54][55][56][57].…”