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.
OBJECTIVE
To develop a systematic review that would address the following question: Should patients with stage II colon cancer receive adjuvant therapy?


METHODS
A systematic review was undertaken to locate randomized controlled trials comparing adjuvant therapy to observation.


RESULTS
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).


CONCLUSIONS
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.
Figueredo
Alvaro
A
Hamilton Regional Cancer Centre, Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main St W, T-27, 3rd Floor, Hamilton, Ontario, Canada L8S 4L8.
Charette
Manya L
ML
Maroun
Jean
J
Brouwers
Melissa C
MC
Zuraw
Lisa
L
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D006801:Humans; D009367:Neoplasm Staging; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome