Conclusions
Concerning the main question about whether there is a role for adjuvant chemotherapy following neoadjuvant combined modality therapy and surgical resection, the answer is simple—yes.  However, the optimal adjuvant chemotherapy to be administered remains an ongoing issue. To date, there has been no definitive randomized study to identify the optimal postoperative adjuvant chemotherapy and the optimal duration of therapy. Despite the absence of such hard clinical data, the general recommendation is to give adjuvant chemotherapy for 4 months in patients with stage II and III rectal cancer. Fluoropyrimidine-based chemotherapy with infusional 5-FU/leucovorin, oral capecitabine(Drug information on capecitabine), and FOLFOX are certainly all reasonable treatment options, depending on the stage of disease. This is similar to what is presently being recommended for the adjuvant therapy of stage II and III colon cancer.[12-14]  

What about the situation in which a patient experiences a pathologic complete response to neoadjuvant chemoradiotherapy? Should this individual receive adjuvant chemotherapy? Again, while there is no study directly addressing this issue, the consensus view is to offer 4 months of therapy with FOLFOX for stage III and high-risk stage II disease, and fluoropyrimidine monotherapy with infusional 5-FU/leucovorin or oral capecitabine for patients with stage II disease.

We eagerly await the results of ongoing studies to determine the role of biologic agents in the adjuvant treatment of patients with surgically resected rectal cancer. The development of key clinical and pathologic factors as well as molecular biomarkers are critically important, since they will help identify which patients are at high risk for tumor recurrence and poor survival, as well as predict which patient subgroup will respond best to a particular treatment regimen and/or experience increased toxicity. Certainly, the goal moving forward is to begin to move away from empiric delivery of chemotherapy and to administer chemotherapy using an individually tailored approach.