Size Matters in Prostate Cancer

Prostate cancer severity can be greater in smaller glands

(RxWiki News) A man's prostate has been described as a walnut-shaped gland. And as with everything else in a man's reproductive system, prostates come in all sizes. New research shows that size may matter in terms of predicting prostate cancer aggressiveness.

The size of man's prostate may offer insight into the seriousness of prostate cancer. The smaller it is, the worse it is. This is the finding of recently published research.

"Find out the prognosis (outlook) of your disease - ask your doctor."

Vanderbilt-Ingram Cancer Center (VICC) researchers conducted a study to see if and how the physical size of the prostate was predictive of the severity of prostate cancer. The paper's first author is fourth-year medical resident Judson Davies, M.D.

Researchers examined the records of 1,251 men who had had a prostatectomy (removal of the prostate) between January 2000 and June 2008.

The men were classified as having low-risk disease. This was determined by low prostate specific antigen (PSA) levels and a Gleason score (measure of cancer severity found during first biopsy) of six or less prior to surgery.

Investigators looked only at these low-risk patients who may have been candidates for less aggressive treatment such as active surveillance.

After pathologists examined the actual tissue removed, the severity of disease was upgraded in about of third (31 percent) of the patients, and men with smaller prostates were more likely to have a change in disease severity.

Daniel Barocas, M.D., MPH, assistant professor of Urologic Surgery and senior author on the study, explained, “Our field suffers from this great confusion because in half of men you can find prostate cancer in microscopic amounts that may not be clinically significant and yet it’s the second leading cause of cancer death among men.

"The more you look for it, the more you find it but that doesn’t help us figure out who needs treatment and who doesn’t,” Dr. Barocas added.

Researchers are trying to find a means to identify which men need to consider more aggressive therapy, so that physicians can counsel their patients effectively.

Prostate cancer is often a slow growing cancer. The way it grows makes imaging difficult, as easily recognized tumors are usually not formed.

Dr. Barocas says that prostate size isn't actually as important as the ratio of PSA to size. That is, if a  smaller prostate is producing a lot of PSA, it's likely the result of "a bad tumor, whereas a large prostate making a lot of PSA is likely to be due to benign enlargement of the prostate (BPH),” said Dr. Barocas.

Still, prostate density is just one more factor to consider, but not definitive. A man who has a small prostate may be at an increased risk of higher grade disease.

According to the paper's authors, more research is needed to find better biomarkers and imaging technology that more accurately determines just how threatening prostate cancers are.

This research was published in the February, 2012 issue of Journal of Urology.


Review Date: 
February 2, 2012