AIM

Adjuvant chemotherapy is recommended for stage III colon cancer. The aim of this study was to identify important prognostic factors among patients with colon cancer receiving adjuvant 5-FU-based treatment.

METHODS

Data sets of 855 colon cancer patients treated between 1992 and 1999 within a multicenter adjuvant trial comparing 5-FU modulation with folinic acid or interfereron-alpha were examined. Backward elimination in a proportional hazards model was used to identify prognostically relevant clinical and pathological factors.

RESULTS

Tumor recurrence (p<0.001), duration of adjuvant treatment (p<0.001), tumor substage (p=0.004), age (p=0.005), grading (p=0.016), treatment-related toxicity (p=0.021), and treatment (p=0.031) were identified in descending order of importance as prognostic factors for overall survival.

CONCLUSIONS

Adjuvant 5-FU-based treatment should be performed for at least 6months with a stepwise adjustment of 5-FU doses until toxicity >WHO II. Substages should be reported separately and used for stratification in future trials due to their broad variation in outcome. In the future, this may result in adjuvant treatment of stage III colon cancer adjusted for the risk of substages.