How often is adjuvant FOLFOX (Adj FOLFOX) discontinued for toxicity among colon cancer patients in the routine care setting?

Abstract

9530 Background: Although 12 cycles of Adj FOLFOX are recommended for stage III and high risk stage II colon cancer, toxicity may preclude completion of treatment. We used the NCCN Colorectal Cancer Outcomes Database to identify how frequently Adj FOLFOX is discontinued prematurely for toxicity in a non-clinical trial population. Methods: Newly diagnosed stage II-III colon cancer pts treated with Adj FOLFOX at 7 NCI-designated comprehensive cancer centers between 9/05–12/07 were identified. We assessed completion of the prescribed adjuvant chemotherapy (AC) course, including Adj FOLFOX and 5FU-based adjuvant treatment alone subsequent to discontinuation of oxaliplatin (oxal). Dose limiting toxicity (DLT) of Adj FOLFOX was defined as premature discontinuation of Adj FOLFOX due to toxicity. We evaluated potential predictors of Adj FOLFOX DLT, including older age and history of diabetes in a multivariable logistic model controlling for stage and center. We measured the duration of Adj FOLFOX use in weeks, from first to last dose. Results: 293 pts began Adj FOLFOX. Pts who experienced DLT (40%) had a shorter duration of Adj FOLFOX and were less likely to complete AC, even after oxal was discontinued. The only significant predictor of experiencing a DLT was a history of diabetes. Conclusions: Our analysis of patients treated outside of a clinical trial demonstrated a notably high rate of discontinuation of Adj FOLFOX due to DLT, particularly in pts with diabetes. The results underscore the need for systematic assessment of toxicity especially among diabetics. [Table: see text] [Table: see text]