Adjuvant Chemotherapy with Fluorouracil and ccnu in Colon Cancer. Results of a Multicentric Randomized Study

Medical Management of Colorectal Carcinomas

Current information on the medical treatment of colorectal cancer was reviewed after a search of the literature through Medline. Publications from 1984 to present were surveyed. Appropriate adjuvant therapy increases overall survival and disease-free intervals. The treatment modalities of unresectable or metastatic tumors are disappointing, with at best 40% of patients experiencing short-lasting responses. Whenever possible, patients with advanced colorectal cancer should be enrolled in clinical trials.

Adjuvant therapy for completely resected stage II colon cancer

BACKGROUND

Colon cancer is potentially curable by surgery. Although adjuvant chemotherapy benefits patients with stage III disease, there is uncertainty of such benefit in stage II colon cancer. A systematic review of the literature was performed to better define the potential benefits of adjuvant therapy for patients with stage II colon cancer.

OBJECTIVES

To determine the effects of adjuvant therapy on overall survival and disease-free survival in patients with stage II colon cancer.

SEARCH STRATEGY

Ovid MEDLINE (1986-2007), EMBASE (1980-2007), and EBM Reviews - Cochrane Central Register of Controlled Trials ( to 2007) were searched using the medical headings "colonic neoplasms", "colorectal neoplasms", "adjuvant chemotherapy", "adjuvant radiotherapy" and "immunotherapy", and the text words "colon cancer" and "colonic neoplasms". In addition, proceedings from the annual meetings of the American Society of Clinical Oncology and the European Society of Medical Oncology (1996 to 2004) as well as personal files were searched for additional information.

SELECTION CRITERIA

Randomized trials or meta-analyses containing data on stage II colon cancer patients undergoing adjuvant therapy versus surgery alone.

DATA COLLECTION AND ANALYSIS

:Three reviewers summarized the results of selected studies. The main outcomes of interest were overall and disease-free survival, however, data on toxicity and treatment delivery were also recorded.

MAIN RESULTS

With regards to the effect of adjuvant therapy on stage II colon cancer, the pooled relative risk ratio for overall survival was 0.96 (95% confidence interval 0.88, 1.05). With regards to disease-free survival, the pooled relative risk ratio was 0.83 (95% confidence interval 0.75, 0.92).

AUTHORS' CONCLUSIONS

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 significantly 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.

Adjuvant therapy of colon cancer: a review

Colon cancer is a common cause of cancer-related mortality. Complete surgical resection of the primary tumor and/or select metastatic lesions can be curative in many patients. The risk of recurrence after resection can be predicted by pathologic staging. Large prospective randomized trials over the past 2 decades have clearly shown an increased overall survival for patients with resected stage III colon cancer who are treated with adjuvant 5-fluorouracil-based chemotherapy. The benefit of adjuvant chemotherapy for patients with stage II disease remains controversial. There is indirect evidence to support adjuvant chemotherapy after resection of metastatic disease. Locoregional approaches such as radiation, hepatic arterial infusion, or portal vein chemotherapy remain investigational. Adjuvant immunotherapy with monoclonal antibodies is emerging as a therapeutic option that might complement chemotherapy. Future challenges include improving adjuvant chemotherapy with the addition and/or substitution of new agents, resolving which subset of patients with stage II and resected stage IV colon cancer might benefit from therapy, validating the benefit of immunotherapy, and investigating locoregional therapies compared with systemic therapy.

The role of adjuvant chemotherapy in the treatment of colorectal cancer

Adjuvant therapy is clearly of great benefit for certain patients with colorectal carcinoma. Validation of new prognostic markers to further define which patients are at highest risk of recurrence will be important. Future investigation for adjuvant therapy includes incorporation of achievements made in the advanced disease setting, including biochemical modulation of 5-FU, identification of new active agents, and incorporation of immunotherapy strategies into adjuvant treatment programs. Further improvements in the treatment of these patients, even if small, may translate into important benefits, given the large number of patients presenting annually with this common cancer. As our therapeutic options broaden and improve, investigators will need to focus on quality of life and pharmacoeconomic parameters to determine which adjuvant approaches are optimal for the individual patient with colorectal cancer, as well as for society in general.