Detecting prostate cancer by the intracellular presence of prostate-specific antigen in macrophages, detected in peripheral blood samples by a flow cytometric technique.

Prostate cancer, besides lung cancer, is the most common cancer in men. In the
Netherlands prostate cancer has an incidence of approximately 6.61 per 1,000
men per year (NKR 2007). Given this, more than 9800 new patients will be
diagnosed with prostate cancer in the Netherlands.
Using prostate-speci*c antigen (PSA), a widely used serum marker for prostate
cancer, the incidence of this diagnosis has been increasing. PSA is a protein
formed by the normal and abnormal prostate, which is normally present in the
blood to a limited extent. It is assumed this marker is a measure of the
activity of certain parts of the prostate tissue.
However, PSA is not in all forms of prostate cancer elevated and elevated PSA
is not always associated with cancer. It is also known that, with increasing
age, the content of PSA in the blood can increase without finding abnormalities
of the prostate. Equally, the PSA can be elevated in both prostatitis and
benign prostatic hyperplasia (BPH).
PSA has a limited specificity in prostate cancer detection. Patients with serum
PSA levels > 4 ng/mL will undergo prostate biopsy for further histological
examination. This is often a stressful and painful procedure for the patient.
Up to 75% of men who undergo prostate biopsy because of PSA values between 4-10
mg / l do not have prostate cancer. Often re-biopsies are performed.

At the Atrium Medical Center Heerlen, in 2005 a study has been initiated with
the aim of developing a new diagnostic tool for patients with prostate
carcinoma. By using flow cytometry, PSA can be measured in activated monocytes,
naming macrophages. These monocytes migrate into (cancer)tissues in which they
differentiate into functionally distinct macrophages. Afterwards, when they
have incorporated debris and possibly tumour tissue by active phagocytosis,
they will turn back into the bloodstream.
This new diagnostic tool is able to detect tumor tissue in activated
macrophages (imPSA, intracellular macrophage PSA) in the peripheral blood of
patients with prostate carcinoma. It is able to produce a significant
difference between BPH and prostate carcinoma.
In recent years a lot of effort is invested in improving this technique. That
study is part of this effort. Blood samples will be taken of men with
complaints of their prostate when visiting the outpatient department of
Urology. These samples will be tested for imPSA by flow cytometry.

Objective of the study:
To study and evaluate whether PSA in activated macrophages in peripheral blood
samples of patients with prostate cancer is a more specific and sensitive
marker for differentiating between benign and malignant prostate diseases than
the conventional serum total PSA or not.

Blood samples in EDTA tubes will be collected from every patient. These will be
immunocytochemical stained, after which the mononuclear cells will be isolated
and further investigated with monoclonal antibodies (CD14 and CD16) using a
standard protocol.
After this, these samples will be stained intracellular with a PSA antibody.
Finally the samples will be flow cytometric analysed.

Blood samples will be taken by a medical student, BSc.

Statistical analysis will be performed using SPSS/GraphPad Prism/Excell.

While taking blood samples, in rare cases, a serious adverse event (SAE) can
take place. This can be a phlebitis or a venous bleeding. Worst case scenario
will be a shock; only this event will a part of the SAE-regulation of the CCMO.