Exploratory Investigation of Predictive Factors for Reducing Adverse Effects in CapeOX Therapy for Colorectal Cancer...

Oxaliplatin infusion plus oral capecitabine (CapeOX) is the standard chemotherapy regimen for colorectal cancer. It is commonly employed as adjuvant therapy and as first-line treatment for advanced disease. However, adverse effects, such as peripheral neuropathy, hand-foot syndrome, and gastrointestinal symptoms, may lead to dose reduction or discontinuation. Identifying reliable predictors of these adverse effects would support prophylactic strategies and enable safer, more personalized treatment.

We retrospectively analyzed 108 colorectal cancer patients who received CapeOX between September 2020 and October 2023. Adverse events after the first cycle were evaluated using Common Terminology Criteria for Adverse Events (CTCAE) v5.0 and categorized into Grade 0 and Grade ≥ 1 groups. Associations between pre-treatment blood test values (including aspartate aminotransferase (AST), alanine aminotransferase (ALT), red blood cells, monocytes, and basophils) and inflammatory or nutritional indices (including prognostic nutrition index (PNI), systemic inflammatory response index (SIRI), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR)) were examined for adverse events. Variables demonstrating significant associations in univariate analysis were included in a multivariate logistic regression model. Receiver operating characteristic analysis was performed to determine optimal cut-off values of predictive markers.

AST ≤ 22.0 IU/L was identified as a significant predictor of peripheral neuropathy. Nausea was significantly associated with a basophil count ≥ 0.28 × 10²/μL and occasional alcohol intake; anorexia with a basophil count ≥ 0.29 × 10²/μL and PLR ≤ 152.69; and diarrhea with a SIRI ≤ 0.37. These markers enabled effective risk stratification of adverse drug reactions in patients undergoing CapeOX.

Certain adverse effects of CapeOX may be predicted using routine pre-treatment laboratory data. These findings could facilitate early identification of high-risk patients and enable personalized preventive interventions.