Search for theragnostic biomarkers in colorectal liver metastases: Focus on the host immune cells

The prognostic factors of patients with colorectal liver metastases (CLM) have been traditionally searched among the factors related to the primary colorectal tumor or to CLM. While many different scoring systems have been developed based on those traditional clinic-pathological factors, there has been the introduction of genetic biomarkers that added a theragnostic perspective. More recently, other important factors, such as those related to the host immune system, have been proposed as new determinants of prognosis of CLM patients. We herein review the current prognostic factors of CLM patients focusing on the burgeoning shifting paradigm of prognostication that relies on the host immune system.