Systematic Review: Adjuvant Chemotherapy for Locally Advanced Rectal Cancer with respect to Stage of Disease

Background. Recent meta-analysis of 21 randomised controlled trials (RCTs) supports the use of adjuvant chemotherapy for nonmetastatic rectal carcinoma. In order to define a subgroup of patients who can potentially benefit from postoperative adjuvant chemotherapy, this study aims to review trials investigating adjuvant chemotherapy with respect to stage of disease in patients with locally advanced rectal cancer who had undergone surgery for cure (stage II and stage III). Methods. We searched electronic information sources to identify randomised trials evaluating adjuvant chemotherapy in patients with stages II and III rectal cancer with overall survival or disease-free survival as outcomes. Scottish Intercollegiate Guidelines Network notes on methodology were used to assess the methodological quality of the selected studies. Random-effects models were applied to calculate pooled outcome data. Results. Eight studies reporting total of 5527 patients were selected for analysis. Adjuvant chemotherapy was associated with statistically significant improvement in disease-free survival and overall survival compared to surgery alone in both stage II and stage III cancer. Conclusions. This study indicates that both stage II and stage III rectal cancer patients may benefit from postoperative adjuvant chemotherapy. However, the benefits of adjuvant chemotherapy for patients who already had neoadjuvant chemoradiation still remain unknown.