Women who experienced six or more symptoms of posttraumatic stress disorder (PTSD) at some point in life had a twofold greater risk of developing ovarian cancer compared with women who never experienced any PTSD symptoms. These findings were published by Roberts et al in Cancer Research.
The findings indicate that having higher levels of PTSD symptoms—such as being easily startled by noises or avoiding reminders of a traumatic experience—can be associated with increased risks of ovarian cancer even decades after women experience a traumatic event. The study also found that the link between PTSD and ovarian cancer remained for the most aggressive forms of ovarian cancer.
“In light of these findings, we need to understand whether successful treatment of PTSD would reduce this risk, and whether other types of stress are also risk factors for ovarian cancer,” said study coauthor Andrea Roberts, PhD, MPH, research scientist at Harvard T.H. Chan School of Public Health.
Studies in animal models of ovarian cancer have shown that stress and stress hormones can accelerate ovarian tumor growth, and that chronic stress can result in larger and more invasive tumors. A prior study found an association between PTSD and ovarian cancer in humans, but the study included only seven women with ovarian cancer and PTSD.
“Ovarian cancer has been called a ‘silent killer’ because it is difficult to detect in its early stages; therefore, identifying more specifically who may be at increased risk for developing the disease is important for prevention or earlier treatment,” said study coauthor Laura Kubzansky, PhD, MPH, Lee Kum Kee Professor of Social and Behavioral Sciences at Harvard Chan School.
“Ovarian cancer has relatively few known risk factors—PTSD and other forms of distress, like depression, may represent a novel direction in ovarian cancer prevention research.”— Shelley Tworoger, PhD
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To better understand how PTSD may influence ovarian cancer risk, researchers analyzed data from the Nurses’ Health Study II. Participants were asked about ovarian cancer diagnosis on each questionnaire, and information was validated through a review of medical records.
In 2008, 54,763 Nurses’ Health Study II participants responded to a supplemental questionnaire focused on lifetime traumatic events and symptoms associated with those events. Women were asked to identify the event they considered the most stressful, as well as the year of this event. They were also asked about seven PTSD symptoms they may have experienced related to the most stressful event.
Based on the responses, women were divided into six groups: no trauma exposure; trauma and no PTSD symptoms; trauma and one to three PTSD symptoms; trauma and four to five PTSD symptoms; trauma and six to seven PTSD symptoms; and trauma but PTSD symptoms unknown.
After adjusting for various factors associated with ovarian cancer, including oral contraceptive use and smoking, the researchers found that women who experienced six to seven symptoms associated with PTSD were at a significantly higher risk for ovarian cancer than women who had never been exposed to trauma (age-adjusted hazard ratio = 2.10, 95% confidence interval = 1.12–3.95). Women with trauma and four to five symptoms were also at an elevated risk, but the risk did not reach statistical significance.
The study also showed that women who experienced six to seven symptoms associated with PTSD were at a significantly higher risk of developing the high-grade serous histotype of ovarian cancer.
“Ovarian cancer has relatively few known risk factors—PTSD and other forms of distress, like depression, may represent a novel direction in ovarian cancer prevention research,” said study coauthor Shelley Tworoger, PhD, Associate Center Director of Population Science at Moffitt Cancer Center. “If confirmed in other populations, this could be one factor that doctors could consider when determining if a woman is at high risk of ovarian cancer in the future.”
Disclosure: Funding for this study came from the Department of Defense. For full disclosures of the study authors, visit cancerres.aacrjournals.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.