[Adjuvant chemotherapy in rectal cancer]

Abstract

Like in colorectal carcinoma stage III (Dukes' C), patients with rectal carcinoma stage II (Dukes' B2) and III (Dukes' C) have a relatively poor prognosis with a 5-year survival chance less than 50%. Adjuvant postoperative irradiation reduces the risk for locoregional relapse to a less extend than preoperative radiotherapy; however, both modalities have only little or no influence on the total disease-free and overall survival. Adjuvant chemotherapy however reduces significantly the risk of distant metastases and--although there is no influence on the risk for locoregional relapse--increases significantly the chance for total disease-free and overall survival. A combination of both modalities, adjuvant systemic chemotherapy and adjuvant postoperative irradiation parallel to the chemotherapy, results not only in a significantly improved disease-free and overall survival but also in a significant decreased locoregional failure rate. Since the local relapse in patients with rectal cancer might cause severe symptoms and a bad quality of life for the patient, the reduction of a locoregional relapse rate by about 50% is of major benefit for the patient who would suffer from relapse. Since the overall toxicity of a combined radio-chemotherapy is not thoroughly increased by modern technique irradiation, the combined radio-chemotherapy using 45-54 Gy, multiple field technique and 5-FU bolus single agent chemotherapy is currently regarded the adjuvant treatment of choice for patients with stage-II and stage-III rectal carcinoma. Further improvement has been demonstrated by a continuous infusion of 5-FU concurrent to the irradiation with a significant decreased locoregional as well as distant failure rate and significant increased survival rate.(ABSTRACT TRUNCATED AT 250 WORDS)