Blood-based Biomarkers at Large Bowel Endoscopy and Prediction of Future Malignancies

Soluble cancer-related protein biomarker levels may be increased in subjects without findings at large bowel endoscopy performed due to symptoms associated with colorectal cancer. The present study focused on a possible association between increased biomarker levels in such subjects and subsequent development of malignant diseases. In a major study of 4,990 subjects undergoing large bowel endoscopy, 691 were without pathology and comorbidity. Plasma levels of TIMP-1, CEA, CA19-9, and YKL-40 were determined in samples collected just before endoscopy and compared with subsequent development of a malignant disease within a period of 7–8 years. The upper 90% limits of the reference levels of every single protein were used to differentiate between normal and increased levels. The levels were separated into three groups: 0, none of the biomarkers increased; 1, one biomarker increased; 2, two or more biomarkers increased. A total of 43 subjects developed a primary malignant disease in the observation period. Univariatly, increase of all four biomarkers was significantly associated with subsequent development of a malignant disease. A multivariate analysis showed that increased biomarker levels were associated with subsequent development of a malignant disease (P = 0.002). The cumulative risk of developing malignant disease within the first 5 years after endoscopy was group 0, 3.3%; group 1, 5.8%; group 2, 7.8%. It is concluded that increased levels of plasma TIMP-1, CEA, CA19-9, and serum YKL-40 at large bowel endoscopy without findings may be associated with an increased risk of developing a subsequent malignant disease.