Abstract A25: Public and provider awareness and use of a CA-125 test for ovarian cancer
Authors: Stewart Sherri L. , Rim Sun Hee , Gelb Cynthia A. 
Published: May 2012

Introduction: CA-125 is a serum marker approved for detecting recurrent ovarian cancer in women with a personal history of ovarian cancer. Several large trials have investigated the use of CA-125 (alone or in combination with transvaginal ultrasound [TVU]) as a screening test for ovarian cancer. However, this test has generally been associated with a low positive predictive value and trials have concluded that screening asymptomatic women in the average risk population with CA-125 is not beneficial. Still, there remains widespread discussion and marketing of ovarian cancer screening tests that include CA-125. Since little is known about public and provider awareness of CA-125, the objective of this study was to measure women's familiarity with the CA-125 test, and clinician beliefs about the effectiveness of screening for ovarian cancer with CA-125 in the United States.

Methods: In 2008, CDC funded the collection of data as part of its national awareness campaign, Inside Knowledge: Get the Facts About Gynecologic Cancer. Several questions related to CA-125 were included as part of a standardized, survey administered annually in the contiguous United States by Porter Novelli. The HealthStyles survey included 2,991 female respondents age ≥ 18 years, and the DocStyles survey included 1,250 physician respondents of family/general practitioners (n=510), internists (n=490), and obstetrician/gynecologists (n=250). Participant responses to CA-125-related questions for the HealthStyles survey were weighted to match the demographic distribution of the general population. Chi-square tests were used to assess differences with the p-value set to 0.05.

Results: Overall, most women (56%) had not heard of the CA-125 test, 29% had heard of it, and 15% were unsure. Demographic characteristics generally were similar for women who had not heard of the CA-125 test, except that women who had heard of the test more often were over age 45 (58% vs 37%) (p&lt;0.0001) and were peri- or post-menopausal (54% vs 35%) (p&lt;0.0001), compared to women who had not heard of CA-125. Few women (12%) had ever had a CA-125 test. About 15% of women who reported being “very concerned” about getting ovarian cancer also reported having had a CA-125 test. In the DocStyles results, the majority (53%) of physicians said that both CA-125 and TVU are effective screening tests for ovarian cancer. A greater proportion of OB/GYNs (57%) reported neither CA125 nor TVU were effective as screening tests for asymptomatic women in the average risk population than family/general practitioners (34%) or internists (30%) (p&lt;0.0001).

Conclusions: The large percentage of physicians who believe CA-125 is an effective screen for ovarian cancer signals the need for improved education. Educational efforts geared toward the public and providers that include both lack of evidence for screening with CA-125, as well as the potential harms of false-positive CA-125 tests should be a priority for public health programs and awareness campaigns.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A25.