MONDAY, Nov. 3, 2003 (HealthDayNews) -- A cellular protein called PCa-24 has been identified as a unique marker for prostate cancer.
The discovery of the protein, which will be published in the Dec. 15 issue of Cancer, could lead to development of a screening test that clearly distinguishes between prostate cancer and benign prostatic hyperplasia (BPH) before doctors perform a biopsy.
The research was led by Dr. Brian Liu, an assistant professor of surgery and urology at Brigham and Women's Hospital in Boston. He and his colleagues used proteomics -- the study of all proteins produced by a cell -- to identify PCa-24, which is unique to prostate cancer cells and is a smaller protein than prostate specific antigen (PSA).
In this study, PCa-24 was exclusively detected in 94 percent of epithelial cells from prostate cancer but was not detected in normal prostate cells or in BPH cells.
"One possible application for our findings is to determine the presence or absence of this protein in serum of patients with prostate cancer versus those with other urologic diseases, including BPH," the authors write.
Currently, screening for prostate includes testing levels of PSA. Values of PSA greater than 4 can warrant further evaluation with a needle biopsy.
But PSA can be produced in high levels by either prostate cancer or BPH, which is a nonmalignant disease that causes narrowing of the urethra and difficulty urinating. Also, nearly 35 percent of men with prostate cancer have normal PSA values.
This means that measuring PSA serum level alone is not a specific marker for prostate cancer and may result in unnecessary needle biopsies.
Here's where you can learn more about prostate cancer.