Intact and cleaved forms of the urokinase receptor enhance discrimination of cancer from non-malignant conditions in patients presenting with symptoms related to colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality in developed countries. It is known that early detection results in improved survival, and consequently there is a need for improved diagnostic tools in CRC. The plasma level of soluble urokinase plasminogen activator receptor (suPAR) was proposed as a marker in CRC patients. This study was undertaken to evaluate the individual molecular forms of suPAR as discriminators in a group of patients undergoing endoscopical examination following symptoms related to colorectal cancer. METHODS: In a case-control study comprising 308 patients undergoing endoscopical examination following CRC-related symptoms, 77 CRC patients with adenocarcinoma were age and gender matched to: 77 patients with adenomas; 77 with other non-malignant findings, and 77 with no findings. The different uPAR forms were measured in citrate plasma collected before endoscopical examination, using three different Time Resolved - Fluorescence Immuno Assays (TR-FIA's). RESULTS: All soluble uPAR forms were found to be significantly higher in cancer patients than in patients presenting with other non-malignant findings; uPAR(I) P=0.0006, suPAR(I-III) P<0.0001 and suPAR(I-III)+(II-III) P<0.0001, whereas no significant difference was found when performing similar comparisons for patients presenting with adenomas. The odds ratio (OR) for the comparison of uPAR(I) in patients with CRC to subjects with other non-malignant findings was 3.44 (95% CI:1.86-6.37). CRC patients had a mean elevated level of 20.9% (95% CI:10.2-32.6) for suPAR(I-III) and 18.5% (95% CI:9.0-28.8) for suPAR(I-III)+(II-III) compared with subjects with non-malignant findings. CONCLUSIONS: The findings confirm reports on increased uPAR expression in cancer patients and in particular elevated levels of suPAR in blood from CRC patients and indicate that suPAR levels in blood are increasing during carcinogenesis. Although none of the measured uPAR forms were cancer specific, our findings suggest that uPAR expression could be useful in the early detection of CRC when combined with other markers and clinical variables.

Changes in plasma TIMP-1 levels after resection for primary colorectal cancer.

BACKGROUND: Increased plasma levels of tissue inhibitor of metalloproteinases (TIMP-1) are associated with poor outcome in colorectal cancer (CRC), however postoperative changes in plasma TIMP-1 levels after resections for CRC have not been thoroughly evaluated. MATERIALS AND METHODS: Plasma samples were collected from 45 patients with primary CRC, preoperatively, 2 hours after surgery, and at days 1, 2, 7, 28, 45, 60, 75 and 90 after surgery. TIMP-1 and CEA levels were determined using the ARCHITECT Immunoanalyzer. RESULTS: Postoperatively, the mean (geometric) TIMP-1 level increased and had a maximum level at day 1 (p < 0.0001). The mean TIMP-1 level then declined to a level at day 90 similar to the mean preoperative level. CONCLUSION: A mean decline in plasma TIMP-1 levels was not observed within 90 days. However, individual significant reductions of plasma TIMP-1 levels did occur within 28-60 days postoperatively.

Assessment of the biological variation of plasma tissue inhibitor of metalloproteinases-1.

BACKGROUND: Tissue inhibitor of metalloproteinases-1 (TIMP-1) measurements in plasma may be useful for the early detection and prognosis of colorectal cancer (CRC). Data on analytical performance and normal intra- and interindividual biological variation are required in order to interpret the utility of TIMP-1 in CRC. The aim of this study was to establish the biological and analytical variation of plasma TIMP-1 in volunteers. MATERIAL AND METHODS: Three separate studies were undertaken. 1: Plasma was collected from 23 volunteers 6 times within a 3-week period, first in September 2004 (round [R] 1), then repeated in May 2005 (R2) and May 2006 (R3) in the same group of individuals. TIMP-1 levels were determined by the MAC15 ELISA assay and with the Abbott ARCHITECT i2000 Immunoanalyzer. 2: Circadian variation was evaluated in plasma collected 7 times within a 24-hour period (n=16). 3: Effects of physical exercise were evaluated in plasma collected before and after bicycling (n=14). In studies 2 and 3 TIMP-1 levels were determined with the MAC15 ELISA assay only. RESULTS: A significant correlation between TIMP-1 MAC15 and ARCHITECT i2000 was shown (rs=0.78, p<0.002), with consistently higher levels being detected by the ARCHITECT i2000. Median levels of TIMP-1 (ARCHITECT) at 8 a.m. in each round were 74.9 ng/mL (range 65.7-89.9) (R1), 87.3 ng/mL (range 72.7-127.9) (R2), and 81.9 ng/mL (range 66.8-113.6) (R3). The within-subject variation was 10.7%, the variation between rounds was 7.4%, and the intraclass correlation was 46.2%. Comparison between the 3 rounds and time of collection showed that TIMP-1 values decreased by 11% after storage for more than 16 months (p=0.0002). A systematic circadian variation in plasma TIMP-1 levels was not observed (p=0.17). No significant variation of plasma TIMP-1 was found in relation to physical exercise (p=0.92 [global test]). CONCLUSION: Levels of plasma TIMP-1 in volunteers show limited circadian, day-to-day, week-to-week and season-to-season variation. In addition, physical exercise has no impact on plasma TIMP-1 levels. Possible storage-dependent decreases in plasma TIMP-1 levels warrant further investigation.