[Adjuvant and neoadjuvant therapy of rectal carcinoma. The current status]

Abstract

Background: The Consensus Conference of the German Cancer Society (CAO/AIO/ARO, 1.7.1998) has recently updated recommendations for patients with rectal cancer. Instead of a former reservation regarding the indication of adjuvant therapy for rectal cancer the actual version of the consensus particularly emphasizes the role of postoperative radiochemotherapy for stage-II/III tumors. This article reviews the most recent and ongoing trials of adjuvant and neoadjuvant therapy of rectal cancer.

Results: To avoid local recurrence is the most important aspect in the primary treatment of rectal cancer. In some series, e.g. the results of the Surgical Department of the University of Erlangen, a significant correlation between local control and survival was noted. The final results of the Swedish Rectal Cancer Trial with 1168 randomized patients not only confirmed the potential of radiotherapy to reduce local recurrence rate, but also demonstrated a significant survival advantage for patients receiving short-course preoperative radiation therapy. Postoperative combination therapy is usual in the United States and in most European countries since the publication of two randomized trials of the Gastrointestinal Tumor Study Group (GITSG) and the North Central Cancer Treatment Group (NCCTG). The survival advantage resulting from an adjuvant radiotherapy with conventional doses and concurrent fluorouracil-based chemotherapy as compared to surgery alone was recently confirmed in a Norwegian trial. Protracted venous 5-fluorouracil infusion should further improve treatment results. Numerous phase-II studies have demonstrated the efficacy of preoperative radiochemotherapy with high rates of pathological response. Thus, neoadjuvant radiochemotherapy is recommended for patients with locally advanced tumor primarily not amenable to curative surgery. Prospective randomized trials are ongoing to clarify the role of preoperative versus postoperative combined treatment for patients with resectable rectal cancer.

Conclusion: Radiochemotherapy for rectal cancer is recommended as standard treatment outside clinical trials for stage II/III patients after curative treatment and for patients with T4-tumor prior to surgery. The optimal use of chemotherapy and the sequence of treatment modalities remains to be elucidated.