Adjuvant therapy for stage II colon cancer: a systematic review from the Cancer Care Ontario Program in evidence-based care's gastrointestinal cancer disease site group. American Society of Clinical Oncology recommendations on adjuvant chemotherapy for stage II colon cancer. Adjuvant therapy for stage II colon cancer after complete resection. Provincial Gastrointestinal Disease Site Group. Pooled analysis of fluorouracil-based adjuvant therapy for stage II and III colon cancer: who benefits and by how much? Randomized trial of the efficacy of adjuvant chemotherapy for colon cancer with combination therapy incorporating the oral pyrimidine 1-hexylcarbamoyl-5-fluorouracil. Long-term results of single course of adjuvant intraportal chemotherapy for colorectal cancer. Swiss Group for Clinical Cancer Research (SAKK) Adjuvant therapy with edrecolomab versus observation in stage II colon cancer: a multicenter randomized phase III study. Randomised controlled trial of adjuvant chemotherapy by portal-vein perfusion after curative resection for colorectal adenocarcinoma. Adjuvant intraperitoneal 5-fluorouracil in high-risk colon cancer: A multicenter phase III trial.
To develop a systematic review that would address the following question: Should patients with stage II colon cancer receive adjuvant therapy?
                A systematic review was undertaken to locate randomized controlled trials comparing adjuvant therapy to observation.
                Thirty-seven trials and 11 meta-analyses were included. The evidence for stage II colon cancer comes primarily from a trial of fluorouracil plus levamisole and a meta-analysis of 1,016 patients comparing fluorouracil plus folinic acid versus observation. Neither detected an improvement in disease-free or overall survival for adjuvant therapy. A recent pooled analysis of data from seven trials observed a benefit for adjuvant therapy in a multivariate analysis for both disease-free and overall survival. The disease-free survival benefits appeared to extend to stage II patients; however, no P values were provided. A meta-analysis of chemotherapy by portal vein infusion has also shown a benefit in disease-free and overall survival for stage II patients. A meta-analysis was conducted using data on stage II patients where data were available (n = 4,187). The mortality risk ratio was 0.87 (95% CI, 0.75 to 1.01; P =.07).
                There is preliminary evidence indicating that adjuvant therapy is associated with a disease-free survival benefit for patients with stage II colon cancer. These benefits are small and not necessarily associated with improved overall survival. Patients should be made aware of these results and encouraged to participate in active clinical trials. Additional investigation of newer therapies and more mature data from the presently available trials should be pursued. To address whether all medically fit patients with curatively resected stage II colon cancer should be offered adjuvant chemotherapy as part of routine clinical practice, to identify patients with poor prognosis characteristics, and to describe strategies for oncologists to use to discuss adjuvant chemotherapy in practice.
                An American Society of Clinical Oncology Panel, in collaboration with the Cancer Care Ontario Practice Guideline Initiative, reviewed pertinent information from the literature through May 2003.
                A literature-based meta-analysis found no evidence of a statistically significant survival benefit of adjuvant chemotherapy for stage II patients. Recommendations The routine use of adjuvant chemotherapy for medically fit patients with stage II colon cancer is not recommended. However, there are populations of patients with stage II disease that could be considered for adjuvant therapy, including patients with inadequately sampled nodes, T4 lesions, perforation, or poorly differentiated histology.
                Direct evidence from randomized controlled trials does not support the routine use of adjuvant chemotherapy for patients with stage II colon cancer. Patients and oncologists who accept the relative benefit in stage III disease as adequate indirect evidence of benefit for stage II disease are justified in considering the use of adjuvant chemotherapy, particularly for those patients with high-risk stage II disease. The ultimate clinical decision should be based on discussions with the patient about the nature of the evidence supporting treatment, the anticipated morbidity of treatment, the presence of high-risk prognostic features on individual prognosis, and patient preferences. Patients with stage II disease should be encouraged to participate in randomized trials. Should patients with resected stage II colon cancer receive adjuvant therapy?
                To make recommendations regarding the use of adjuvant therapy in the treatment of resected stage II colon cancer.
                Overall survival is the primary outcome of interest. Secondary outcomes are disease-free survival and adverse effects of the treatment regimens.
                Evidence was selected and reviewed by 2 members of the Provincial Gastrointestinal Disease Site Group (GI DSG) of the Cancer Care Ontario Practice Guidelines Initiative. The recommendations resulting from this review have been approved by the GI DSG, which comprise medical and radiation oncologists, surgeons and epidemiologists. Community representatives did not participate in the development of this practice guideline but will do so in future guidelines development.
                There are 25 published randomized controlled trials (RCTs) and 1 meta-analysis. The GI DSG pooled data from 11 of the 25 RCTs that provided adequate data.
                The 25 RCTs are grouped according to the type of therapy and whether the control patients received no treatment (observation) or other adjuvant therapy after resection. Because the trials usually included patients with stage II and III cancer, the complete trial results and those for a subset of patients with stage II disease were analysed. Although the overall trial results showed a survival benefit for adjuvant treatments, the benefit was not significant for stage II patients. A meta-analysis of 11 trials comparing adjuvant treatment with observation in patients with stage II cancer indicated no significant reduction in the odds ratio (OR) for death (OR 0.83; 95% confidence interval [CI] 0.62 to 1.10). The OR for death among patients receiving chemotherapy by portal vein infusion (PVI) was 0.62 (95% CI 0.35 to 1.11).
                The toxic effects of 5-fluorouracil (5-FU) with either levamisole or leucovorin, or both, were mild to moderate and consisted mostly of stomatitis, diarrhea and myelosuppression; 5% of patients required hospital admission. 5-FU plus levamisole was associated with transient neurotoxic effects in 18% of patients. Toxic effects associated with PVI were mild, rare and mostly consisted of leukopenia and diarrhea; 1% of patients experienced bowel perforation.
                Adjuvant therapy is not recommended at this time for the routine management of patients with resected stage II colon cancer. Patients with stage II disease and high-risk factors (bowel obstruction, tumour adhesion, invasion, perforation or aneuploidy) have a poorer prognosis, similar to that of patients with stage III colon cancer. For individual management, these patients should be made aware of their prognosis; treatment can be considered after the uncertainty of the value of adjuvant therapy has been explained to the patient. The enrolment of patients with high-risk stage II disease in clinical trials is encouraged. Trials comparing adjuvant therapy with observation are needed and are ethically acceptable in stage II colon cancer. Although it is well-established that fluorouracil- (FU-) based adjuvant therapy improves survival for patients with resected high-risk colon cancer, the magnitude of adjuvant therapy benefit across specific subgroups and for individual patients has been uncertain.
                Using a pooled data set of 3,302 patients with stage II and III colon cancer from seven randomized trials comparing FU + leucovorin or FU + levamisole to surgery alone, we performed an analysis based on a Cox proportional hazards regression model. Treatment, age, sex, tumor location, T stage, nodal status, and grade were tested for both prognostic and predictive significance. Model derived estimates of 5-year disease-free survival and overall survival (OS) for surgery alone and surgery plus FU-based therapy were calculated for a range of patient subsets.
                Nodal status, T stage, and grade were the only prognostic factors independently significant for both disease-free survival and OS. Age was significant only for OS. In a multivariate analysis, adjuvant therapy showed a beneficial treatment effect across all subsets. Treatment benefits were consistent across sex, location, age, T-stage, and grade. A significant stage by treatment interaction was present, with treatment benefiting stage III patients to a greater degree than stage II patients.
                Patients with high-risk resected colon cancer obtain benefit from FU-based therapy across subsets of age, sex, location, T stage, nodal status, and grade. Model estimates of survival stratified by T stage, nodal status, grade, and age are available at http://www.mayoclinic.com/calcs. This information may improve patients' and physicians' understanding of the potential benefits of adjuvant therapy. The purpose of the present trial was to clarify the efficacy of postoperative adjuvant chemotherapy including an oral fluoropyrimidine anticancer drug, the 1-hexylcarbamoyl-5-fluorouracil (HCFU), for the treatment of colon cancer.
                Patients with clinical stage Dukes' B and C colon cancer, who had been treated surgically, were assigned to a chemotherapy group treated with mitomycin C, 5-fluorouracil (5-FU), and HCFU and to a control group that received no postoperative adjuvant chemotherapy.
                Of the 1,001 patients registered for the study, 17 (1.7%) were ineligible. The incidence of toxicity was significantly higher in the chemotherapy group than in the control group. However, there were few severe side effects and no deaths related to the treatment. Overall survival showed no significant difference between the groups. The disease-free survival or the recurrence-free intervals was significantly higher in the chemotherapy group than in the control group. The incidence of hepatic recurrence was significantly (P=0.003) lower in the chemotherapy group than in the control group.
                The results of this study demonstrated the efficacy of adjuvant chemotherapy for colon cancer, i.e., combined chemotherapy that included the 5-FU oral anticancer drug HCFU. The efficacy of adjuvant chemotherapy after surgery for colorectal cancer remains unproven. We have investigated the efficacy of a perioperative intraportal cytotoxic regimen in a randomised trial of 533 patients with operable colorectal carcinoma. Patients were randomly assigned either a single course of portal infusion with mitomycin (10 mg/m2, one dose) plus fluorouracil (500 mg/m2 per 24 h for 7 days) starting immediately after surgery, or no adjuvant treatment. 505 (94%) were evaluable. At median follow-up of 8 years, adjuvant therapy reduced the risk of recurrence by 21% (hazard ratio 0.79 [95% CI 0.62-1.00], p = 0.051) and the risk of death by 26% (0.74 [0.57-0.97], p = 0.026). The lower risk of relapse was observed in all subgroups based on node status or localisation of the tumour; the risk reduction was greatest in patients with tumour-involved lymph nodes (Dukes' C; 0.67 [0.45-0.99], p = 0.045) and for those with colon cancer (0.78 [0.56-1.09], p = 0.151). Most of the difference in overall and disease-free survival could be attributed to a consistent reduction of all kinds of tumour recurrences (local relapses, liver metastases, and other distant metastases) in the treated group, rather than to a reduction of liver relapses only. We conclude that part of the benefit obtained with a single course of adjuvant chemotherapy via the portal vein for patients with operable colorectal carcinoma might be due to the systemic effects of the portal chemotherapy. In a phase III study recruiting patients with stage II colon cancer the effect of adjuvant therapy with edrecolomab, a murine monoclonal antibody to the cell-surface glycoprotein 17-1A, was compared to observation alone.
                From January 1997 until July 2000 a total of 377 patients were postoperatively stratified according to tumor stage (T3 vs. T4) and center, and randomly allocated to either treatment with edrecolomab (cohort A, n = 183) or observation (cohort B, n = 194). Patients in cohort A received a total of 900 mg edrecolomab. The study was terminated prematurely because of discontinuation of drug supply in Germany.
                305 patients were eligible for the primary endpoint of overall survival and 282 patients for disease-free survival. After a median follow-up of 42 months overall survival and disease-free survival were not significantly different. Toxicity was mild.
                In the present study, postoperative adjuvant treatment with edrecolomab in patients with resected stage II colon cancer did not improve overall or disease-free survival. About half the patients treated with curative resection for colorectal cancer do not survive long-term. Adjuvant chemotherapy given during and after surgery may prevent hepatic metastases and improve patient survival. In patients with colorectal cancer, we have done a multicentre, randomised controlled trial comparing five-year survival after intraportal infusion of fluorouracil (1 g per day) plus heparin (10,000 U per day) (130 patients) or heparin alone (123) during curative resection and for 7 days thereafter, or after resection alone (145). There was no reduction in liver metastasis or increased overall survival advantage in either active-treatment arm of the study. However, patients who had stage III, Dukes' C (lymph-node-positive) tumours resected and were treated with fluorouracil plus heparin had a significant (p less than 0.03) survival advantage of about 16% compared with surgery-only controls. Further study of intraportal infusion of chemotherapeutic agent as adjuvant treatment to surgery in patients with colorectal cancer appears worthwhile. To evaluate the results of a prospective multicenter randomized study of adjuvant intraperitoneal 5-fluorouracil (5-FU) administered during 6 days shortly after resection of stages II and III colon cancers.
                Systemic adjuvant chemotherapy improves the survival of patients with stage III colon cancer receiving treatment for 6 months. Intraperitoneal chemotherapy theoretically combines peritoneal and hepatic effects.
                After resection, 267 patients were randomized into two groups. Patients in group 1 (n = 133) underwent resection followed by intraperitoneal administration of 5-FU (0.6 g/m2/day) for 6 days (day 4 to day 10). These patients also received intravenous 5-FU (1 g) during surgery. Patients in group 2 underwent resection alone (n = 134).
                In group 1, 103 patients received the total dose, 18 received a partial dose as a result of technical or tolerance problems, and 12 did not receive the chemotherapy. Rates of surgical death and complications were similar in both groups. Tolerance to treatment was excellent or fair in 97% of the patients and poor in 3%. After a median follow-up of 58 months, 5-year overall survival rates were 74% in group 1 and 69% in group 2; disease-free survival rates were 68% and 62%, respectively. Survival curves were superimposed until 3 years after treatment and began diverging thereafter. Among patients receiving the full treatment, the 5-year disease-free survival rate was improved in the treatment group in patients with stage II cancers but was unchanged in patients with stage III cancers.
                Chemotherapy with intraperitoneal 5-FU administered during a short period after surgery was well tolerated but was not sufficient to reduce the risk of death significantly. However, it reduced the risk of recurrence in stage II cancers. These results suggest that it should be associated with systemic chemotherapy to reduce both local and distant recurrences.
: Although there was no improvement in overall survival in the pooled analysis, we did find that disease-free survival in patients with stage II colon cancer was signficantly better with the use of adjuvant therapy. It seems reasonable to discuss the benefits of adjuvant systemic chemotherapy with those stage II patients who have high risk features, including obstruction, perforation, inadequate lymph node sampling or T4 disease. The co-morbidities and likelihood of tolerating adjuvant systemic chemotherapy should be considered as well. There exists a need to further define which high-risk features in stage II colon cancer patients should be used to select patients for adjuvant therapy. Also, researchers must continue to search for other therapies which might be more effective, shorter in duration and less toxic than those available today.