Prognostic value of tumor-infiltrating immune cells in patients with colorectal cancer

Currently, the treatment of advanced colorectal cancer (CRC) differs and oncologists face complicated decisions in the choice of the most suitable treatment options for their patients. Predictive and prognostic biomarkers can simplify clinical decision making. Prognostic factors are those parameters that separate a population in terms of their clinical outcome in the absent of treatment. Predictive factors are those that identifies patients base on clinical outcome in response to particular treatment or lack of response to specific treatment (1,2). Validation of prognostic markers can be performed by data from a retrospective series of patients treated with standard cares. However, analysis of quality randomized clinical trials (RCTs) use for validation of predictive markers (2). Histopathological characteristics such as: the size of the tumor, atypical cell morphology, aberrant expression of protein and recently genetic markers applied to estimate the patient prognosis or predict clinical outcome. In addition, average disease-free survival (DFS), disease-specific survival (DSS), overall survival (OS) or other available statiscal data are used for the estimation (3).