Importance of the field: Gastrointestinal (GI) cancers are frequently associated with high rates of mortality and morbidity, often resulting from late detection, underscoring the need for improved early detection, risk assessment and intervention. Screening approaches available at present are inadequate, and the development of accurate non-invasive biomarkers is needed.
Areas covered in this review: A comprehensive review is provided on the current state of blood-based biomarkers for diagnosing GI cancers, with a focus on the next generation of new genetic and epigenetic blood-based tests.
What the reader will gain: It is anticipated that the reader will have a detailed view on the potential of blood-based biomarkers for GI cancers. Although the premise of detecting cancers in blood has been explored previously, recent technological advances have revolutionized the field of non-invasive biomarkers. Consequently, there is unprecedented evidence that it is perhaps the time when a systematic identification of highly specific and sensitive markers may be an essential component in the era of 'personalized medicine'.
Take home message: In spite of the limited success of first-generation tests, data gathered in recent years clearly support the notion that we are on the verge of discovering and optimizing a new generation of non-invasive diagnostic biomarkers for GI neoplasia.