Prostate cancer laboratory studies

Biopsy
If cancer is suspected, a biopsy is offered. During a biopsy a urologist or radiologist obtains tissue samples from the prostate via the rectum. A biopsy gun inserts and removes special hollow-core needles (usually three to six on each side of the prostate) in less than a second. Prostate biopsies are routinely done on an outpatient basis and rarely require hospitalization. Fifty-five percent of men report discomfort during prostate biopsy.

Tumor markers
Tissue samples can be stained for the presence of PSA and other tumor markers in order to determine the origin of maligant cells that have metastasized.

New tests being investigated
Currently, an active area of research involves non-invasive methods of prostate tumor detection. Adenoviruses modified to transfect tumor cells with harmless yet distinct genes (such as luciferase) have proven capable of early detection. So far, though, this area of research has only been tested in animal and LNCaP models.

PCA3
Another potential non-invasive method of early prostate tumor detection is through a molecular test that detects the presence of cell-associated PCA3 mRNA in urine. PCA3 mRNA is expressed almost exclusively by prostate cells and has been shown to be highly over-expressed in prostate cancer cells. PCA3 is not a replacement for PSA but an additional tool to help decide if, in men suspected of having prostate cancer, a biopsy is really needed. The higher the expression of PCA3 in urine, the greater the likelihood of a positive biopsy, i.e. the presence of cancer cells in the prostate. Company Diagnocure has an exclusive worldwide license for all diagnostic and therapeutic applications related to PCA3

Early prostate cancer
It was reported in April 2007 that a new blood test for early prostate cancer antigen-2 (EPCA-2) is being researched that may alert men if they have prostate cancer and how aggressive it will be.

Prostasomes
Epithelial cells of the prostate secrete prostasomes as well as PSA. Prostasomes are membrane –surrounded, prostate-derived organelles that appear extracellularly and one of their physiological functions is to protect the sperm from attacks by the female immune system. Cancerous prostate cells continue to synthesize and secrete prostasomes and may be shielded against immunological attacks by these prostasomes. Research of several aspects of prostasomal involvement in prostate cancer has been performed.

Prostate mapping
Prostate Mapping is a new diagnostic process developed by urology and radiology consultants in the UK. This is a method of diagnosis which may be accurate in determining the precise location and aggressiveness of cancer. It uses a combination of multi-sequence MRI imaging techniques and a template guided biopsy system and involves taking multiple biopsies through the skin that lies in front of the back passage rather than through the back passage. The procedure is carried out under general anesthetic.

Gleason score
The tissue samples are then examined under a microscope to determine whether cancer cells are present, and to evaluate the microscopic features (or Gleason score) of any cancer found.