Prostate cancer, the most common type of cancer in the US killing
more than 30000 a year, is caused by a slow-growing malignant tumour in the
prostate gland. In most cases the tumour will remain dormant even until the death
of the patient, usually elderly men, but should it develop untreated, it can
spread to other organs through blood and lymph. Over 75% of the patients live
for at least 15 more years after the initial diagnosis. During the later stage,
patients typically experience disruptions and difficulties in urination
.Treatments of the cancer depend on the stage, patient’s age, and many other
factors. Methods include surgical removal, radiation, chemotherapy, hormonal
manipulation or a combination of these.
The most common way to detect prostate cancer is by prostate antigen
specific (PSA) screening. The tumour interferes with prostate cells, causing
the release of PSA which is detected through blood tests. Yet the use of this
test has always been controversial as it has an equally significant amount of
benefits and harms. The benefit is self-explanatory, while harms include
causing blood clotting, which have led to heart attacks, and impotence or
incontinence. Also, the level of PSA is cofounded by other factors such as age
and heredity. PSA test cannot tell whether the tumour is benign and is
inaccurate. Hence new, improved types of PSA tests set specific ranges for
different age groups as well as the percentage of free (as opposed to bound)
PSA circulating the blood. People suffering from prostate cancer are likely to
have lesser free PSA.
Another novel method to detect prostate cancer exploits metabolites
as potential biomarkers. They give us an understanding of biological reactions
which is important in developing diagnostic and therapeutic treatment for
specific diseases. Measuring metabolite concentrations in urine has potential
usage in detecting noninvasive diseases, because changes in metabolite
concentration hints to affected signaling and control processes. Analyzing
metabolite levels can characterize cancer progression. Previously, detecting
specific metabolites is difficult due to inaccurate techniques. It has now been
made easier and more accurate by oxidizing the metabolite enzymatically to
produce formaldehyde. The changes the pH can be visualized using fluorescein in
acetone. Sarcosine was used since it may be usable to diagnose prostate cancer.
It was oxidized with sarcosine oxidase to formaldehyde then to formic acid;
fluorescein can visualize this chain. This method has a correlation coefficient
of 0.9961 and can detect up to 20nmolL-1. Applying this method to
urine samples hints that it is viable, economical and lacks interferences. Analyzing metabolite levels can characterize
cancer progression.
