COMPARATIVE EFFECTIVENESS OF ORAL 5-FLUOROURACIL MONOTHERAPY AS ADJUVANT CHEMOTHERAPY FOR HIGH-RISK STAGE-II COLON CANCER.
Byung jun Yoon*, Jung Rae Cho, Heung-Kwon Oh
Department of Surgery, Seoul National University Bundang Hospital, Seongnam, Korea (the Republic of)
Adjuvant chemotherapy is recommended for patients with stage-II colon cancer who are considered at high risk. However, adjuvant oxaliplatin-based chemotherapy could result in cumulative dose-dependent drug toxicity, such as peripheral neuropathy. This study aimed to elucidate the comparative effectiveness of oral 5-fluorouracil (5-FU) monotherapy as adjuvant chemotherapy for high-risk stage-II colon cancer. This single-institution observational study included patients who underwent curative resection for colonic adenocarcinoma with high-risk stage-II pathology between 2003 and 2014. High-risk pathological features were defined as T4 lesions, obstruction, perforation, lymph node harvest of <12, lymphovascular/perineural invasion, or poor differentiation. Patients were classified into one of the following three treatment groups: observation group; oral 5-FU agent group (OG); or intravenous chemo-agent group (IVG), including 5-FU/leucovorin or oxaliplatin, in accordance with the clinician's judgment or patient's will. We identified 307 patients, including 85 (27.7%) in the observation group, 127 (41.4%) in the OG, and 95 (30.9%) in the IVG. Those in the OG were older than those in the IVG (65.5 ± 10.7 vs. 56.0 ± 11.3, p = 0.000). The OG had more obstructions and perforations than the IVG (42.5% vs. 25.3%, p = 0.008 and 22.8% vs. 13.7%, p = 0.085, respectively). T4 lesions were found more in the IVG than the OG (43.2% vs. 21.3%, p = 0.000). Sex and lymphovascular/perineural invasions were not significantly different between the OG and the IVG. In terms of oncological outcomes, the 5-year overall and disease-free survival rates were not significantly different between the OG and the IVG (92.1% vs. 94.7%; p = 0.443, 87.4% vs. 84.2%; p = 0.497, respectively). In multivariable Cox regression analysis, the type of adjuvant chemotherapy also was not associated with survival. Chemotherapy-related adverse events were less frequently observed in the OG than in the IVG (68.5% vs. 97.9%, p = 0.000). In patients with high-risk stage-II colon cancer, adjuvant chemotherapy using oral 5-FU agent proved to be an effective alternative with comparable oncological outcomes to IV chemotherapy, reducing chemotherapy-induced complications.
Back to 2019 Posters
