Ultrasound Beats Blood Test for Gauging Ovarian Cancers:Study

Ultrasound Beats Blood Test for Gauging Ovarian Cancers:Study
THURSDAY, Nov. 15 (HealthDay News) -- Ultrasound exams are betterthan blood tests at identifying whether ovarian tumors are benign ormalignant, a team of international researchers reports.
Ultrasound correctly identified 93 percent of tumors as benign orcancerous, while the blood test was correct 83 percent of the time.
Results of the study, by the International Ovarian Tumor Analysiscollaboration group (IOTA), were published online Nov. 13 in theJournal of the National Cancer Institute.
"To my knowledge, the IOTA study is the first study that clearlydemonstrated that in experienced hands, ultrasound is significantly betterthan blood tests,'" said study leader Dr. Dirk Timmerman, a researcher atKatholieke Universiteit Leuven in Belgium.
An estimated 22,430 new cases of ovarian cancer are expected to bediagnosed in 2007 in the United States, according to the American CancerSociety, with about 15,280 deaths. The disease typically strikes womenover age 55. Symptoms include bloating, pelvic or abdominal pain,difficulty eating or feeling full quickly, or urinary symptoms such as afrequent need to urinate.
Because the symptoms are often similar to less serious conditions, onlyabout 20 percent of ovarian cancers are found at an early stage, thecancer society estimates. This makes the quest for the best techniques todetect the cancer early even more important.
For the IOTA study, Timmerman and his colleagues compared ultrasoundwith blood tests to decide if the ovarian masses discovered in 1,066 womenwere benign or malignant.
Experts examined patterns in ultrasound images, and then compared thoseresults with blood tests that detect an elevated level of the proteinCA-125, considered an indicator of whether an ovarian tumor is cancerousor benign.
The ultrasound exams, including transvaginal gray-scale and colorDoppler ultrasound exams, were given within 120 days of surgery to removethe tumors. Before surgery, 809 of the women gave blood, and the sampleswere analyzed later for CA-125 levels.
When the results from both methods were compared with the findings atsurgery, the researchers found that ultrasound correctly classified 93percent of tumors as cancerous or not, while the blood test was correct inonly 83 percent of cases.
"The IOTA study not only demonstrated that ultrasound is better thanblood tests but also that the blood tests do not give additional benefitin mathematical models developed to distinguish between benign andmalignant masses," Timmerman said.
Timmerman emphasized that the study only looked at the best method todecide if a tumor was cancerous after the mass had already beendiscovered. "Of course, this is different from screening," he said. "Inscreening studies, a healthy population is screened for a specificdisease, for example, ovarian cancer. In that setting, a blood test mightprove to be useful in the future." He noted that two large studiesexploring that issue are expected to conclude in about five years.
Dr. Robert Morgan, co-director of the gynecologic oncology/peritonealmalignancy program at the City of Hope Cancer Center in Duarte, Calif.,said the study results confirm what doctors have known for a long time."CA-125 is only elevated in about 50 percent of early stage ovariancancer, and the data in this paper confirms that," he said.
The study's bottom line: Most of these cancers are being picked up withultrasound, not the blood test, Morgan said. "And, most of the time, when[the ultrasound] says it's not malignant, it's not," he said.
''C-125 tests are not cheap and, particularly when you do them in ahuge number of patients, the costs add up. And, apparently, they don'tseem to be adding anything to the diagnostic accuracy," he added.
Sherry Salway Black, executive director of the Ovarian Cancer NationalAlliance, called the new study results exciting. "It gives moreinformation, more evidence that a transvaginal ultrasound can be effectiveunder these circumstances."
Still, she said, the blood test might prove to have some benefit. "Itmay not be the best stand-alone diagnostic tool. This [study] appears tosay transvaginal ultrasound is definitely better." But the study authorsdid find that CA-125 levels in women found to have cancer were higher forpostmenopausal women than premenopausal women, for instance. And suchdetails, Black said, might prove valuable.
Meanwhile, a study from Boston's Brigham and Women's Hospital has foundthat regular consumption of foods containing the flavonoid kaempferol,including nonherbal tea and broccoli, was associated with a reduced riskof ovarian cancer. The study, funded by the National Cancer Institute andpublished in the Nov. 15 issue of the International Journal ofCancer, also found a decreased risk in women who consumed largeamounts of the flavonoid luteolin, found in carrots, peppers and cabbage.
"This is good news, because there are few lifestyle factors known toreduce a woman's risk of ovarian cancer," first author Margaret Gates, aresearch fellow at the hospital, said in a prepared statement. "Althoughadditional research is needed, these findings suggest that consuming adiet rich in flavonoids may be protective."
"Other flavonoid-rich foods, such as onions, beans and kale, may alsodecrease ovarian cancer risk, but the number of women who frequentlyconsumed these foods was not large enough to clearly evaluate theseassociations. More research is needed," concluded Gates, who is also aresearch fellow at the Harvard School of Public Health.