Tailoring treatment of rectal adenocarcinoma: immunohistochemistry for predictive biomarkers

Over the past couple of decades, multimodality treatment for the management of resectable rectal cancer has substantially improved the outcome of affected patients. However, the broad and unpredictable response to tumor of patients with rectal cancer treated with preoperative chemoradiotherapeutic interventions shows that our understanding of the molecular events leading to radioresistance in patients affected with this malignancy remains sparse. Multiple attempts by individual molecular markers in gene array and tissue microarray studies have emerged with the goal of identifying predictors of a response to chemoradiation in patients with rectal cancer. In this report, we discuss the status of the markers currently available in an attempt to tailor specific targeted therapies for rectal cancer in the neoadjuvant setting.