Ovarian Cancer Study Underway in North Carolina
DURHAM, N.C. - In the next four years, about 1,400 women in 48 counties across North Carolina are expected to participate in a Duke Comprehensive Cancer Center study to examine genetic changes and risk factors for ovarian cancer. Researchers hope a better understanding of ovarian cancer will lead to improvements in early diagnosis and prevention in the future.
Ovarian cancer is the leading cause of death from reproductive system cancers in women, and 25,200 new cases are expected in the United States in 1999, according to the American Cancer Society. About 14,500 women will die from ovarian cancer this year in the United States. Among all cancers in women, ovarian cancer is the fifth most common and the fifth deadliest.
There are no good methods of early detection and screening for ovarian cancer presently, says Dr. Andrew Berchuck, co-principal investigator of the study. The best plan of action is to learn more about how the disease gets started and how to prevent it, he says. A big part of prevention is identifying risk factors that increase a woman's likelihood of developing ovarian cancer and then acting on that knowledge.
"There's a lot we don't know about ovarian cancer," says Berchuck, professor of gynecologic oncology. "This is still a highly fatal disease, but if we can understand it, maybe we can prevent it."
Early ovarian cancer frequently goes undetected, since few physical symptoms appear until the cancer's growth interferes with other functions, such as digestion. As a result, most diagnoses are of late stage disease that is very difficult to treat. Knowing risk factors might help doctors catch the disease in earlier stages.
For example, if a woman was known to have risk factors for ovarian cancer and symptoms that could be ovarian cancer or could be something else, doctors might look for ovarian cancer earlier. "We could take that patient down a different route than someone without risk factors for the disease," Berchuck says.
The study, called the North Carolina Ovarian Cancer Study, is headquartered at Duke, but hospitals and physicians from west of Charlotte to the Atlantic coast will be participating. As a population-based study, the researchers hope to learn more than if patients from only one site were included.
"The participants represent the spectrum of ovarian cancer in North Carolina and not just a select population," says principal investigator Joellen Schildkraut, an epidemiologist and associate professor in the department of community and family medicine.
The North Carolina Central Cancer Registry will provide the names of recently diagnosed ovarian cancer patients, with approval of the patients' doctors, and a nurse from the study will contact those patients. If they want to participate, a nurse will schedule an in-person interview at each patient's home where potential risk factors will be discussed. All information will be kept confidential.
Using blood and tumor samples from each patient, the researchers also will look for non-inherited genetic mutations that might correlate with risk factors or lead to causes of the disease. "What makes this epidemiological study unique," explains Schildkraut, "is that we're examining specific tumor changes and correlating those with information from the questionnaire."
Potential risk factors and genetic characteristics of 700 patients with ovarian cancer will be compared to those of 700 women who've never had cancer, identified to match patient participants. The researchers hope comparing the two groups will highlight differences that could be related to ovarian cancer.
While the link between risk factors and genetic differences will be examined, it will be years after the study is finished before any might be used as screening methods or to provide treatment options. But patients who participate in the study do benefit.
"Participation in and of itself makes patients feel good," says Schildkraut, "and a lot of patients want to do something for the future."
Berchuck agrees: "It's a highly lethal disease, so patients have a stake in participating in studies that will improve chances for future generations."
About 5 percent to 10 percent of ovarian cancers are thought to have a strong hereditary association, particularly in patients who develop the disease at a young age, Berchuck says. The genes BRCA1 and BRCA2 in particular are known to heighten women's risk of developing both ovarian cancer and breast cancer. Investigators at Duke were involved in the discovery of these two cancer susceptibility genes five years ago.
Berchuck, Schildkraut, and others at Duke identified lifetime ovulations as a primary risk factor for developing ovarian cancers with a certain genetic alteration in a landmark study a few years ago. Their study showed that five-year use of birth control pills reduced ovarian cancer risk by 50 percent, and other ovulation-limiting actions, like pregnancy and breastfeeding, also reduced women's risk, similar to findings of prior studies.
The North Carolina Ovarian Cancer Study is funded by the National Cancer Institute and the Department of Defense. Volunteers can not be accepted as either patients or controls.