Is Prostate Cancer Screening Still Necessary?
The current test for prostate cancer continues to spark debate. In part 1 of WebMD's 2-part series, there's important prostate cancer information that men should have.
Understanding Prostate Cancer and the PSA Exam
The prostate gland is a small walnut-sized organ that sits in a man's pelvis, right behind the pubic bone. The bladder lies just on top; the rectum, just below. The urethra, the tube that carries urine out of the body, runs through the prostate gland, and on either side is a network of nerves that help control sexual function.
The role of the prostate is to produce a substance that mixes with sperm to create semen. Prostate cells also secrete a number of proteins, including prostate specific antigen, or PSA.
"It's important to note that both normal prostate cells and malignant prostate cells produce PSA," says Chinnaiyan.
So how does the PSA relate to prostate cancer?
Experts say a small amount of PSA is always leaked into the bloodstream. Just how much is found in the blood is then used to determine the risk of prostate cancer.
While it seems like a straightforward association, it's not. The reason: According to urologist Simon Hall, MD, there are some men with a very aggressive prostate cancer whose PSA levels are normal. Likewise, there are men whose PSA levels are soaring but who are cancer-free. And right now, no one is sure why.
Still, he tells WebMD, "It's important for men to understand that the PSA does not diagnose cancer; it helps to create a risk profile. It only tells you if your risk is increased," says Hall, chairman of the department of urology at the Mount Sinai School of Medicine in New York City. And, he says, when interpreted properly, it can do just that.
To help further define those risks, doctors frequently perform a second exam known as the DRE or digital rectal exam. In this test the doctor manually examines the prostate through the rectum, checking for shape, symmetry, hardness, and size.
The Prostate Cancer Biopsy: Your Ultimate Diagnostic
Depending on the findings of both the DRE and PSA screenings, the final diagnostic step is frequently a biopsy or sampling of the cells inside the prostate. In this procedure, Lepor says, 12 to 14 cores [cell samples] are removed and tested for the presence of cancer cells and their type, size, and aggressiveness (how fast they are growing).