Testing men with prostate cancer for a substance called endoglin in their blood may help doctors know if the cancer has spread outside the gland to the lymph nodes, new research shows.

It is known that removing the pelvic lymph nodes can provide important information about the prognosis of prostate cancer, but “it is still not clear in whom this procedure should be done,” researcher Dr. Claus G. Roehrborn, from the University of Texas Southwestern Medical Center in Dallas, explained in a statement.

Previous research has identified elevated levels of endoglin in patients with breast cancer and colon cancer that has spread, according to the report in the journal Clinical Cancer Research. Whether endoglin levels are increased in prostate cancer patients had never been looked at until now.

Roehrborn’s team studied 425 men who underwent surgical removal of the prostate as well as removal of the pelvic lymph nodes. The investigators found that men with elevated endoglin levels were more likely to have cancer that had spread to the lymph nodes, as well as other signs of more aggressive cancer.

With standard factors, the researchers could predict with 89 percent accuracy whether the cancer had spread to the lymph nodes. When the endoglin measurement was included, the accuracy rose to 98 percent.

If these results are confirmed in other studies, it might be possible to identify men whose prostate cancer has not spread with more certainty, and so spare them from having their lymph nodes removed.

SOURCE: Clinical Cancer Research, March 1, 2008.