Adjuvant Systemic Therapy in Stage II and III Colon Cancer

The prognosis of colon cancer is primarily determined through staging of the disease. After curative surgery, clinically occult micrometastases are thought to be the major source of disease recurrence. The main aim of postoperative systemic treatment is to eradicate micrometastases, thereby improving outcomes with an increased cure rate. Adjuvant systemic chemotherapy is indicated for patients with stage III colon cancer, as well as for patients with high-risk stage II colon cancer. Prognostic and predictive markers that identify heterogeneous groups are needed to implement tailored therapeutic strategies. Due to the lack of evidence of predictive value of multigene assays in terms of potential value of adjuvant chemotherapy, multigene assays should not be used to determine adjuvant therapy. The standard treatment for most patients with stage III disease is a combination of oxaliplatin with infusional and bolus 5-fluorouracil (5-FU) or with an oral agent such as capecitabine, which has equivalent results. Adjuvant therapy should not be administered to all patients with stage II colon cancer. High-risk stage II patients may be considered as an eligible group for adjuvant therapy after a complete discussion. There is no high level of evidence to use irinotecan-based combination chemotherapies in the adjuvant setting. The antiangiogenic agent bevacizumab in combination with standard adjuvant chemotherapy regimens also failed to improve outcomes, as did the EGFR agent cetuximab. by using findings from clinical trials. Prognostic factors and potential predictive markers of possible benefit of adjuvant systemic therapy will be reviewed, and whether current knowledge in genetic expression profiling helps the physician during decision making will be highlighted. compared different chemotherapy NSABP C-01 trial the first adjuvant of NSABP conducted between November 1977 and February 1983 and included 1166 patients with stage II and III carcinomas of the colon [5]. Patients were randomized to one of three therapeutic categories: (1) no further treatment following curative resection (394 patients); (2) postopera‐ tive chemotherapy consisting of 5-fluorouracil (5-FU), semustine, and vincristine (379 pa‐ tients); or (3) postoperative BCG (393 patients). A comparison between patients who received postoperative adjuvant chemotherapy and those treated with surgery alone indicated that there was an overall improvement in disease-free survival (DFS) ( P = 0.02) and survival ( P = 0.05) in favor of the chemotherapy-treated group. At 5 years of follow-up, patients treated with surgery alone were at 1.29-times the risk of developing a treatment failure and at 1.31-times the likelihood of dying compared with similar patients treated with combination adjuvant chemotherapy. The findings from this study were the first from a randomized prospective clinical trial to demonstrate that a significant DFS and survival benefit can be achieved with postoperative adjuvant chemotherapy in patients with stage II and III carcino‐ mas of the colon who undergo curative resection. of Oxaliplatin/5-FU/Leucovorin in the Adjuvant Treat‐ of Colon Cancer treatment groups. Thus, findings of this Japanese phase III trial confirmed noninferiority of S-1 in DFS at adjuvant setting of stage III colon cancer compared with UFT/LV.