On the technicalities of discovering and applying protein biomarkers for cancer prevention

Primary prevention of cancer is one of the key approaches used to combat cancer. By identifying people at high risk of developing cancer, it becomes possible to develop intervention efforts on prevention rather than treatment. Prevention includes avoiding exposure to known cancer-causing agents, enhancement of host-defence mechanisms, modifying lifestyle and chemoprevention. The latter is the use of specific agents to suppress or reverse carcinogenesis and thereby prevent the development of cancers. Understanding primary molecular events in tumour development is therefore the key. The causes of cancer first produce reversible changes in the target cells, and a long interval is expected between cancer induction and the presentation of disease. Up to now, we had no reliable biomarkers to monitor these primary events, to select high-risk groups and individuals likely to get cancer, and to monitor preventive treatments or strategies to normalize these markers and prevent the individual from getting cancer. Recent developments in proteomic research, however, promise to deliver on these major needs. We here describe the technological armatorium of, and the recent advances in the field of protein biomarker discovery and discuss the future use of protein biomarkers for (1) reliable identification of high-risk groups; (2) clinical guidance of preventive strategies; and (3) elucidation of the mechanism of action for novel (natural product) prevention therapies and regimens.