Adjuvant Therapy for Rectal Cancer

Summary: Background: Adjuvant therapy is an integral component in the management of rectal cancer. Two broad approaches have been used: preoperative and postoperative. Although there are relative advantages and disadvantages of each approach, investigators from Scandinavia, Great Britain, the Netherlands, and other selected European countries advocate preoperative radiation therapy, most commonly delivered with an intensive short course (25 Gy in 5 treatments followed by surgery one week later), without chemotherapy. In contrast, most investigators in North America have advocated the postoperative approach with conventional radiation and 5-FU-based chemotherapy.
Methods: Our own results and the relevant literature regarding adjuvant and neoadjuvant radiochemotherapy for rectal cancer are reviewed with an emphasis on clinical management and future directions.
Results: More recently, in North America as well as in an increasing number of European and South American countries, there has been a shift toward preoperative combined modality therapy. This shift is based on data that suggest less acute toxicity and an increase in sphincter preservation with preoperative compared with postoperative combined modality therapy.
Conclusions: There is still much controversy regarding the ideal sequencing (preoperative vs. postoperative), techniques (intensive short course vs. conventional course), and the use of concurrent chemotherapy in rectal cancer. Randomized trials should provide a definitive answer to these questions within the next few years. Phase I/II trials examining the use of new chemotherapeutic agents in combination with pelvic radiation therapy are in progress.