Adjuvant Chemotherapy and Prognostic Factors in Stage II Colon Cancer - Izmir Oncology Group Study

Background: Although adjuvant chemotherapy is a standard treatment in stage III colon cancer, its benefitis not as clear for stage II patients. In this retrospective analysis, we aimed to evaluate the survival of patientswith low-risk stage II colon cancer, the efficacy of adjuvant chemotherapy in high-risk stage II colon cancerpatients, and prognostic factors in stage II disease. Materials and
Methods: One hundred and seventeen patientswho were diagnosed with stage II colon cancer between January 2006 and December 2011 were included inthe study. Patients were stratified into two groups as being low-risk and high-risk according to risk factorsfor stage II disease. Adjuvant 5-fluorouracil-based chemotherapy were administered to the patients with riskfactors.
Results: Ninety-four patients were treated with adjuvant chemotherapy due to high risk factors and 23were monitored without treatment. Median follow-up time was 43 months. In terms of disease free survival andoverall survival, adjuvant chemotherapy did not provide a statistically significant difference. Univariate analysisdemonstrated that bowel obstruction was the major risk factor for shortened disease-free survival, while bowelperforation and perineural invasion were both negative prognostic factors for overall survival.
Conclusions:The recommendation of adjuvant chemotherapy for stage II colon cancer is not clear. In our study, it was foundthat adjuvant chemotherapy did not contribute to survival in high-risk stage II patients. Due to the fact thatprognosis of stage II patients is good, many more patients will be needed for statistically significant differences insurvival. Adjuvant chemotherapy containing 5 fluorouracil is being used to high-risk stage II patients althoughit is not a standard treatment approach.