RESUMO
Surgery has remained the mainstay of treatment of rectal cancer but due to high local recurrence rates,adjuvant chemoradiation has become standard practice for advanced rectal cancer.In 1990,postoperative chemoradiation has been established by NCI based on the results of GITSG,NCCTG and intergroup studies.However,the German CAO/ARO/AIO 94 study showed that preoperative chemoradition is better than postoperative in terms of local control and acute toxicity.The 5-year cumulative incidence of local relapse was lower in patients assigned to pre-operative chemoradiation vs postoperative treatment Grade 3 or 4 acute toxic effects occurred in 27% of patients in pre-op group vs 40% in post-op group.The corresponding rates of long-term toxic effects were 14% and 24%,respectively.Preoperative chemoradiation has been the trend of treatment of advanced rectal cancer.