Objective: Tissue inhibitor of metalloproteinase-1 (TIMP-1) plays a major role in the regulation of tissue growth, including cancer growth. The TIMP-1 protein can be determined in plasma, and increased plasma levels of TIMP-1 are associated with a poor prognosis of colorectal cancer patients. The aim of the present study was to evaluate whether tumour tissue release of the TIMP-1 protein contributes to the increased plasma levels of TIMP-1 observed in patients with colorectal cancer.
Material and methods: Preoperative blood samples from a peripheral vein and intraoperative blood samples from a tumour artery, a tumour vein and from a peripheral vein were drawn from 24 patients undergoing elective, intended curative surgery for primary rectal cancer. TIMP-1 levels were determined concurrently in plasma from all samples using a validated ELISA method. Counts of white blood cells and platelets were also carried out.
Results: No significant differences between plasma TIMP-1 levels could be demonstrated in any compartment. In particular, there was no significant difference in TIMP-1 levels in plasma from tumour arteries and tumour veins. However, there was a significant decrease in neutrophil cell counts from tumour arteries to tumour veins (p<0.001).
Conclusions: The present results do not support the current hypothesis that tumour cells contribute substantially to increased plasma TIMP-1 levels observed in patients with colorectal cancer.