Prostate cancer
Several MMPs, including MMP-1, MMP-2, MMP-7, MMP-
9, MMP-13, and MMP-14, are reported to be upregulated in
the prostate cancer tissue or in the blood from prostate cancer
patients [105–108]. A high level of MMP-7 in the circulation
was recently found to be an independent risk factor for pros-
tate cancer-related death [109, 110]. Furthermore, patients
with metastatic prostate cancer had significantly higher plas-
ma levels of MMP-2 and MMP-9 than patients with organ-
confined carcinomas and healthy controls [107]. Similarly,
increased level of pro-MMP-9 was found both in serum
samples as well as in tissue extracts of patients with metastatic
prostate cancer compared with patients with localized disease.
In the same study, a higher ratio of active MMP-2 versus pro-
MMP-2 was found in tissue extracts from patients with met-
astatic disease compared with extracts from patients with
localized disease or benign prostate hyperplasias [111].
Increased expression of MMP-2, MMP-9, MMP-11, and
MMP-13 by tumor or stromal cells has also been associated
with increased risk of biochemical recurrence (increased
blood levels of prostate-specific antigen) [105, 106, 112],
whereas high concurrent expression of MMP-2 and the
MMP-inducer EMPRIN (CD147) predicted poor survival in
patients with prostate carcinomas [108]. On the contrary,
increased MMP-9 expression in tumor cells was found to be
associated with prolonged disease-specific and overall surviv-
al (univariate analyses) in a study including 278 patients with
organ-confined prostate cancer, whereas MMP-2, MMP-3,
MMP-13, and MMP-19 had no prognostic value [113].
Expression of TIMP-1, TIMP-2, or TIMP-3 in the blood or
tumor tissue of patients with prostate cancer showed no sig-
nificant prognostic value [105–107, 114].
Concluding remarks regarding MMPs as biomarkers
To our knowledge, MMPs and TIMPs are not commonly
used as prognostic markers or in treatment stratification in
hospitals today. This is most likely due to the conflicting
results published and the existence of more reliable prog-
nostic markers. The combination of several MMPs or
MMPs together with other prognostic markers seems to be
the most promising way of using MMPs as biomarkers.