Faecal immunochemical tests for haemoglobin: Analytical challenges and potential solutions.

Quantitative faecal immunochemical tests for haemoglobin (FIT) are being used increasingly around the world in colorectal cancer screening programmes, and in patients presenting with lower bowel symptoms to determine who should proceed to further bowel visualisation investigations, usually colonoscopy. The clinical utility of FIT is well reported. There are a number of analytical challenges including pre-analytical variation, difficulty setting up external quality assessment schemes, access to third party internal quality control material and a lack of standardisation or harmonisation of FIT methods. Here we report the work of the International Federation of Clinical Chemistry FIT Working Group. We provide an overview of the main pre-analytical variables; discuss different approaches to external quality assurance of FIT; propose a solution to third party internal quality assurance materials and summarise the challenges of standardisation and harmonisation of FIT.

Serum matrix metalloproteinase 7 levels identifies poor prognosis advanced colorectal cancer patients.

Metalloproteinase 7 (MMP-7) plays an important role in tumor growth, invasion and dissemination, and is secreted to the media. Because of the close implication of MMP-7 in cancer biology, we sought to define the prognostic significance of serum levels of MMP-7 in metastatic colorectal cancer (CRC) and explore its possible impact in the daily clinical practice. MMP-7 expression was determined by enzyme-linked immunoabsorbent assay. We assessed serum MMP-7 levels in 87 healthy controls, 96 patients with nonmetastatic CRC and 120 patients with advanced CRC. Clinical information was gathered from patient files. Cox proportional hazards model was used to assess survival. MMP-7 and the variables associated with prognosis were entered and a backward elimination method was employed to adjust the model. Inclusion criteria was p /= 0.10. Advanced CRC patients have a significant higher mean serum MMP-7 levels (13.4 ng/ml) than those in nonmetastatic CRC (5.5 ng/ml; p < 0.001) and healthy controls (4.2 ng/ml; p < 0.001). In metastatic patients, after adjusting for other prognostic variables, MMP-7 (entered as a continuous variable) is associated with decreased survival (HR 1.016, IC 95% 1.002-1.031). Serum MMP-7 levels are significantly elevated in patients with advanced CRC. In conclusion, MMP-7 is an independent prognostic factor for survival in advanced CRC. In our sample, the risk of death associated to MMP-7 increase is much higher than the risk of death associated to lactate dehydrogenase elevation.