Ask an Expert: Ovarian Cancer with Joellen M. Schildkraut

By Karina Antenucci

The American Cancer Society estimates there are about 19,710 women diagnosed with ovarian cancer in the United States each year. On a relative scale compared to other cancers, such as breast cancer, it has a low incidence. However, ovarian cancer ranks fifth in cancer deaths among women, accounting for more deaths than any other cancer of the female reproductive system.

“The survival rate can be very poor, as it is often diagnosed at a late stage since there is no screening for early detection,” says Joellen M. Schildkraut, PhD, professor of epidemiology, who is nationally recognized for her ovarian cancer research, and is a member of the Cancer Prevention and Control Research Program at Winship Cancer Institute of Emory University. 

In recognition of Ovarian Cancer Awareness Month, we speak with Schildkraut, who gravitated toward this field of study because she loves “putting the puzzle pieces together.” Unfortunately, there are still a lot of puzzle pieces where ovarian cancer is concerned.

Here, Schildkraut explains why that is and how her research aims to identify people at high risk so that they can be more closely monitored and, if needed, treated for this disease before it progresses.

Why doesn’t a screening for ovarian cancer exist?

People have been trying for many years to come up with a screening test. There is an antibody that is indicative of ovarian cancer, but it also relates to other conditions like pregnancy. The antibody test does not do well in detecting early stage disease and therefore doesn’t meet criteria for screening. When you are trying to screen for a rare disease, it’s challenging in any case to come up with an appropriate test. Ovarian cancer is often asymptomatic until it reaches an advanced stage. It’s like looking for a needle in a haystack.

What are the symptoms of ovarian cancer and any risk factors?

Abdominal pain is the big symptom. It usually takes a few tries to determine the cause of this, delaying diagnosis. Risk factors include a person’s age, as the peak diagnosis is between ages 55 and 64. Additionally, family history can be a big clue—if they have early onset cancer or breast cancer in their family. In general, ways to prevent cancer across the board include eating a better diet and exercising. Diabetes as a comorbidity is predictive of poor survival. Non-Hispanic white women are most likely to get it [11.7 per 100,000 annually, according to the American Cancer Society].

Are there any health equity related factors that may affect risk or survival?

We are trying to understand this better in an African American Cancer Epidemiology Study, a multisite, population-based study of the largest cohort of Black women with epithelial ovarian cancer that is a major focus for my research group right now. Health equity factors may play into survival of ovarian cancer.

Black women develop ovarian cancer at an earlier age but less frequently than white women, and their survival rate is worse—41%, compared with 48% in white women. We are trying to determine why by collecting data and taking a “society to cell” approach. This means factoring in everything from the social determinants of health—such as housing and access to health care— in their neighborhoods across the U.S. to individual factors, such as inflammatory-related lifestyle exposures like cigarette smoking, diet, and even body powder use that can lead to a poorer prognosis. Immune markers in the tumor tissue are also being examined because these might reflect why Black women may have a poorer or better immune response. We’ve recently published a paper about inflammation-related exposures and cancer survival based on what we’ve discovered in the study so far.

How are the BRCA1 and BRCA2 genes, commonly recognized as breast cancer genes, also related to ovarian cancer?

For ovarian cancer in general, two of the major genes that affect families are the BRCA1 and BRCA2 genes. A mutation in these genes increases the risk for breast and ovarian cancer, as well as some other cancers. People get screened for mutations in these genes if they have a family history. BRCA1 and BRCA2 are DNA repair genes, so if you have a mutation in these genes, it means you have a deficiency in DNA repair. This is one of the recent breakthroughs for treatment, and gynecologists and oncologists are using this information to make treatment decisions for their patients. However, these genes are rare and not found in everyone with ovarian cancer.

A recent paper I co-authored identified over 20,000 genetic variants to develop a polygenic [a group of genes] risk score. This assessment isn’t a prediction of ovarian cancer but a way to segregate people out that may be at a higher risk than the general population. It hasn’t been put into practice. In general, the risk scores must be paired with other risk factors, not just genetic factors, to really drill down to who is high risk.

Joellen M. Schildkraut is the Jules and Uldeen Terry Distinguished Professor of Women's Health at Rollins School of Public Health. Her research is focused on the integrative epidemiology of ovarian and breast cancers, which combines excellence in study design with state-of-the-art genomic analyses.