SEATTLE — May 7, 2002 — Women at highest risk for ovarian cancer receive less screening and report less worry about getting the disease than women with a lower yet somewhat elevated risk, according to researchers at the Fred Hutchinson Cancer Research Center.
M. Robyn Andersen, Ph.D., M.P.H., an assistant member of Fred Hutchinson's Public Health Sciences Division, and colleagues reported their findings in the April issue of Gynecologic Oncology.
"Women most likely to report high levels of perceived risk and to get screening for ovarian cancer are those at elevated risk with a single relative affected with ovarian cancer, as compared to high-risk women with multiple family members affected by breast and/or ovarian cancer," Andersen said.
"These results suggest that many women need additional education about ovarian-cancer risk. We found that the majority of women overestimate their risk and yet a significant percentage of those at highest risk fail to get the recommended screening."
The findings were based on a survey of 3,257 women designed to measure the relationship between perceived ovarian-cancer risk, worry and screening use. The participants averaged 48 years of age and were well educated; nearly 70 percent had graduated from college.
Of those surveyed, 142 were at high risk due to a strong family history of breast or ovarian cancer and 144 women were at elevated risk due to a single first-degree relative with ovarian cancer. The remaining 2,971 women were considered average risk.
The survey revealed significant differences in screening rates between women at high and elevated risk. While more than 60 percent of those at elevated risk reported having undergone screening, less than half (47 percent) of the high-risk women said they had been tested for ovarian cancer.
"Most of the highest-risk women for ovarian cancer are at very high risk because their relatives have had breast cancer, not ovarian cancer," Andersen said. "However, it appears that many of these women don't make the association between a family history of breast cancer and increased ovarian-cancer risk. The connection isn't as obvious as it would be if their mother or sister, for example, had ovarian cancer."
In addition, the researchers found 32 percent of those at average risk of ovarian cancer had undergone screening, which reflects an overestimation of danger by this group.
"Most women appear to have unrealistic beliefs about their risks for ovarian cancer," Andersen said. "Only 11 percent and 27 percent of the women in the elevated and average-risk groups, respectively, correctly estimated their risk of getting the disease."
The two most hopeful screening tools currently under investigation for high-risk women are the CA125 blood test and/or transvaginal ultrasound. CA125 is a protein found in the blood that in large amounts can signal the presence of ovarian cancer. Transvaginal ultrasound is a radiologic imaging procedure that can detect small tumors as well as benign structural irregularities in the ovaries often associated with menstruation. Typically the blood test is used in conjunction with ultrasound.
A 1994 National Institutes of Health Consensus Conference on Ovarian Cancer recommended ovarian-cancer screening for high-risk women because such women may carry a genetic mutation for inherited breast or ovarian cancer called BRCA1 or BRCA2. While only 5 percent to 10 percent of all ovarian cancers are hereditary, such mutations increase the likelihood of a woman developing ovarian cancer by between 16 percent (one in seven women) and 40 percent (two in five women).
"On the other hand, if a woman with a strong family history gets tested for these mutations and is found to be negative, her risk of ovarian cancer is thought to be approximately average," Andersen said. One in 57 women of average risk develop the disease.
In the absence of genetic screening for BRCA1 and BRCA2, those with a prominent family history of breast and/or ovarian cancer are encouraged to see a gynecological oncologist for ovarian-cancer surveillance at least annually, if not every six months, Andersen said. Such women also are encouraged to be vigilant about breast-cancer surveillance (mammograms and clinical breast checkups every six months, as well as self-exams at least weekly) as these mutations increase the lifetime risk of breast cancer to between 45 percent and 85 percent.
Ovarian-cancer screening for women at elevated risk — those with a single affected family member — is not officially endorsed, Andersen said, as its long-term benefit has not been established in terms of reducing death rates from the disease.
Women in the "elevated risk" category face an increased lifetime risk of between 5 percent and 7 percent (one in 20 women and one in 14 women, respectively.)
"The risk for these women is considerably lower than that of women with a genetic mutation but still considerably higher than that of average-risk women," the researchers wrote. "These women are encouraged to discuss the possibility of screening with their physician and to pursue screening if they feel that their risk of ovarian cancer is sufficient to warrant it, even in the absence of evidence for its effectiveness." This advice echoes the recommendations of the NIH consensus statement on ovarian-cancer screening.
Ovarian cancer is the leading cause of gynecological-cancer death in American women; every year, some 23,000 new cases are diagnosed and 14,000 women die from the disease. Because symptoms are often subtle or non-apparent, about three-quarters of women are not diagnosed until the disease has spread. If the cancer is caught early, the survival rate is more than 90 percent.
Symptoms of the disease include abdominal swelling and/or pain; bloating and/or a feeling of fullness; persistent complaints of gas, nausea and indigestion; a change in bowel habits; and unexplained weight loss or gain.
The National Cancer Institute supported this research, which was conducted in collaboration with the Marsha Rivkin Center for Ovarian Cancer Research in Seattle.
To arrange an interview with Andersen or to obtain a copy of the paper "Worry about Ovarian Cancer Risk and Use of Ovarian Cancer Screening by Women at Risk for Ovarian Cancer," contact Kristen Woodward in Fred Hutchinson Media Relations, (206) 667-5095.
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Fred Hutchinson Cancer Research Center
The Fred Hutchinson Cancer Research Center, home of two Nobel Prize laureates, is an independent, nonprofit research institution dedicated to the development and advancement of biomedical technology to eliminate cancer and other potentially fatal diseases. Fred Hutchinson receives more funding from the National Institutes of Health than any other independent U.S. research center. Recognized internationally for its pioneering work in bone-marrow transplantation, the center's four scientific divisions collaborate to form a unique environment for conducting basic and applied science. Fred Hutchinson, in collaboration with its clinical and research partners, the University of Washington Academic Medical Center and Children's Hospital and Regional Medical Center, is the only National Cancer Institute-designated comprehensive cancer center in the Pacific Northwest and is one of 38 nationwide. For more information, visit the center's Web site at www.fhcrc.org.