Biomolecular prognostic factors in colorectal cancer

There is general agreement that staging of colorectal neoplasms based on classic anatomopathological parameters does not allow accurate selection of patients at higher risk of an adverse outcome. For this reason, identification of new prognostic factors is desirable. Such factors should be easily determined and expressed at an early stage of carcinogenesis. Moreover, it would be useful to identify factors predictive of response to radiotherapy and chemotherapy. Various molecules are involved in the carcinogenetic pathway and metastasis formation. The aim of this review is to analyse whether any of them are currently useful in clinical practice and which of them warrant further study. At present, apart from CEA, whose prognostic value has been known for some time, we do not have sufficient data to definitively incorporate any of the other biomarkers in clinical practice. The most promising factors would appear to be loss of heterozigosity of chromosome 18q21 (DCC) and microsatellite instability. However, other molecules warrant further in-depth study. In particular, growth factor receptors may play a role not only as prognostic factors but also in view of their therapeutic potential.