RESUMO
PURPOSE: Esophageal cancer has a high mortality rate, and its multimodality treatment is often associated with significant rates of severe toxicity. Effort is needed to uncover ways to maximize effectiveness of therapy through identification of predictive markers of response and toxicity. As such, the aim of this study was to identify genes predictive of chemoradiotherapy-induced gastrointestinal toxicity using an immune pathway-targeted approach. METHODS: Adults with esophageal cancer treated with chemotherapy consisting of 5-fluorouracil and cisplatin and 45-50 Gy radiation were recruited to the study. Pre-therapy-collected whole blood was analyzed for relative expression of immune genes using real-time polymerase chain reaction (RT-PCR). Gene expression was compared between patients who experienced severe regimen-related gastrointestinal toxicity vs. those experiencing mild to moderate toxicity. RESULTS: Blood from 31 patients were analyzed by RT-PCR. Out of 84 immune genes investigated, TNF was significantly elevated (2.05-fold, p = 0.025) in the toxic group (n = 12) compared to the non-toxic group (n = 19). Nausea and vomiting was the most commonly documented severe toxicity. No associations between toxicity and response, age, sex, histology, or treatment were evident. CONCLUSIONS: This study supports evidence of TNF as a predictive biomarker in regimen-related gastrointestinal toxicity. Confirming these findings in a larger cohort is warranted.