The Promise of Biological Markers as Prognostic Determinants in Colorectal Cancer

Colorectal cancer is the second main cause of cancer-related death in the Western world. Approximately 75% of patients with colorectal cancer present with localised disease. However, despite curative surgery around 40% of patients still experience disease relapse leading to morbidity and eventual mortality. In the postoperative setting there is clear evidence that adjuvant chemotherapy significantly improves clinical outcomes in patients with colorectal cancer. Chemotherapeutic drugs such as fluoropyrimidines, oxaliplatin and irinotecan are now used as part of standard care and the arsenal of new therapies that have significant activity in this disease is steadily growing. However, the management of patients with potentially curative, locally advanced disease (stage II and III), remains an active area of clinical debate as the overall combined 5-year survival for these patients is 65% and indeed only one third of the 40% of patients who are at risk of relapse derive any benefit from adjuvant chemotherapy treatment. Current staging and risk stratification methods in colorectal cancer, while helpful, have failed to adequately predict clinical aggressiveness and/or response to specific treatments. Our increasing knowledge of cancer biology has generated, and is promising, the development of marker candidates for more accurate prognosis assessment and therapeutic targeting in this disease. However, to date there has been no focused effort to apply these exciting discoveries to maximise patient benefit in well-designed clinical trials that assess the utility of these biological markers in clinical practice. In this issue of ONKOLOGIE, Grabowski and colleagues [Grabowski et al.: Onkologie 2005;28:399‐403] present their results of a small pilot study examining the prognostic value of multi-marker analysis in stage III colorectal cancer. In this study they analyse 5 prognostic markers, including neuroendocrine differentiation, over-expression of the SIALYL-LEX antigen,