Prostate cancer is one of the most common types of cancer in men worldwide and the second leading cause of cancer death in men.

One common method to diagnose prostate cancer is measuring total PSA. Serum PSA is regarded as the standard diagnostic marker for prostate cancer. However, it is not cancer specific and often times results in a high negative biopsy rate and great efforts have been taken to further improve the detection rate of prostate cancer. PSA also has low sensitivity and specificity for detection of prostate cancer.

High levels of serum TPS® in the prostate is a strong indication of cancer cell growth in patients with metastasized prostate cancer under androgen treatment, even in prostate tumors that have lost the ability to produce PSA. TPS® levels coincide with immediate disease progression, and, therefore, may spare these patients the burden of treatment toxicity when treatment is ineffective. TPS® and PSA express two different aspects of prostate cancer.Their combined use clearly demonstrates the value of TPS® as an early indicator of treatment response and may also identify patients with clinical progression even when PSA remains normal.

About Prostate Cancer
This malignant disease is by far the most predominant cancer in men in the United States and Europe. Epidemiologic data indicates that prostate cancer is especially prevalent in men over 50 years of age. The prognosis for prostate cancer is good, given early detection and accurate monitoring of the disease.

Great efforts have been made to further imporve the detection rate of prostate cancer. Currently, digital rectal examination (DRE), histology, and measurement of total PSA are the most widely used tools to diagnose prostate cancer. The widespread use of PSA testing has led to a stage shift at the time of diagnosis toward lower tumor stage and grade.

PSA is a marker used for monitoring patients after prostate surgery. However, therapy for androgen-independent metastasized tumors may induce changes in PSA level that are independent of the anti-tumor effect of chemotherapy. PSA is androgen dependent, thus PSA-associated monitoring does not always reveal disease status.