Study backs ultrasound to judge ovarian malignancy
By Will Dunham
WASHINGTON (Reuters) - Using ultrasound images may be a better way than blood tests to determine whether a woman's ovarian tumor is benign or malignant, European researchers said on Tuesday.
Higher levels of a so-called tumor marker protein called CA-125 in the blood is considered the standard way to judge if an ovarian tumor is benign or malignant, but this method sometimes can yield wrong answers, the researchers said.
Researchers led by Dr. Dirk Timmerman of Katholieke Universiteit Leuven in Belgium tested whether ultrasound assessment of the tumor by an experienced examiner was a better method. Ultrasound employs high-frequency sound waves to create images of things inside the body.
In the study, 1,066 women with ovarian tumors were given an ultrasound examination. Of these women, 809 provided blood samples before surgery to remove the ovarian tumors to be analyzed for CA-125, which is overproduced by ovarian tumor cells.
The ultrasound examiners accurately gauged 93 percent of the tumors as either benign or malignant using a method called pattern recognition, according to the study. The blood tests measuring CA-125 levels, in comparison, accurately determined the nature of 83 percent of the tumors, the researchers said.
"In light of our results, it is difficult to understand why measurement of CA-125 serum levels is such an entrenched part of the preoperative evaluation" of such tumors, they wrote in the Journal of the National Cancer Institute.
The researchers noted that the accuracy of the ultrasound method depends on the experience of the examiner.
"We hope our results will encourage responsible parties to expend more effort and more resources to educate and train those who perform gynecologic ultrasound examinations, so that the potential of the ultrasound technique can be maximized," they wrote.
Ovarian cancer is more common in women after age 50 but is very difficult to detect early. Women with ovarian cancer often have no symptoms or mild ones until it is in an advanced stage and tough to treat.
The American Cancer Society estimates that about 15,000 women will die from ovarian cancer in the United States alone this year, with 22,000 new cases seen. Worldwide there are more than 190,000 new cases of ovarian cancer each year, according to the International Agency for Research on Cancer.
(Editing by Maggie Fox and Eric Beech)