Potential predictive biomarkers in locally advanced rectal cancer treated with preoperative chemo-radiotherapy

Fluorouracil-based preoperative chemoradiotherapyrepresents a standard option for the treatmentof locally advanced rectal cancer. Randomized clinical trials have shown thatfluorouracil concomitant to preoperative radiationenhances tumor shrinkage (with 10% to15% of the patients showing a complete pathological tumor response) compared with preoperative radiation alone. A high responserate is of clinical importance in rectal cancer, since patients whoachieve a complete pathological response mayexperience improved long-term survival. Adding oxaliplatin to fluorouracil-based preoperativechemoradiotherapy has no effect on response of the primary rectaltumor and single-agent fluoropyrimidine remains thestandard chemotherapy in this setting. Despite novel biological insights and therapeutic advances, little is known about potential biological markers able to predict pathological tumor response before treatment and to subsequently impact patients’ prognosis. This review focuses on the current available data on main molecular markers and molecular subtypes and the possible upcoming introduction of such analyses in the clinical setting. (www.actabiomedica.it)