Women who have experienced multiple symptoms of post-traumatic stress disorder have double the risk of developing ovarian cancer, according to a new study authored in part by a researcher from Tampa’s Moffitt Cancer Center.
The research team, which also included members from the Harvard T.H. Chan School of Public Health, found that women who experience six or more symptoms of PTSD in their lifetimes double their risk for ovarian cancer compared to women who’ve never suffered that level of trauma.
Symptoms of PTSD can include being easily startled by ordinary noises, avoiding reminders of a past traumatic experience, feeling isolated and having trouble sleeping. They can still lead to a higher risk of ovarian cancer even years or decades after a traumatic event, the research found. The study, published Thursday in the journal, Cancer Research, also found that the link between PTSD and ovarian cancer remained high for the most aggressive forms 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 Shelley Tworoger, associate cancer director of population science at Moffitt. “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.”
Ovarian cancer is considered the deadliest gynecologic cancer and the fifth most common cause of cancer-related deaths among women in the U.S. Studies in animals have shown that stress and the hormones stress produces can accelerate ovarian tumor growth. That chronic stress often results in larger and more invasive tumors.
“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 Laura Kubzansky, a professor of social and behavioral sciences at Harvard’s Chan School who co-authored the new study.
Researchers analyzed data from the Nurses’ Health Study II, which tracked health care outcomes in tens of thousands of women from 1989 to 2015 through questionnaires submitted every two years. Participants were asked about ovarian cancer, and this information was validated through a review of medical records, the study said.
The questionnaires also asked about traumatic events.
In 2008, 54,763 Nurses’ Health Study II participants responded to a questionnaire focused specifically on traumatic events and the symptoms associated with them. These events ranged from rape, to losing a loved one, to being in a severe car accident or natural disaster like a hurricane. Women were asked to identify the event they considered the most stressful in their life, and list when it happened. Then they were asked about various PTSD symptoms they may have experienced related to that event.
“We have previously published studies linking ovarian cancer risk to depression and anxiety, and the risk is greater there too,” said Tworoger, the Moffitt researcher. “There aren’t many other large studies that confirm these risks, so the next step would be to continue to validate our findings. The goal would be to help identify who is at higher risk for this type of cancer and how we can better screen those patients."
Based on the responses, researchers divided the women participants into six groups, ranging in their exposure to trauma and PTSD. Researchers were able to determine that women who experienced more symptoms of PTSD, up to six or seven, were at a significantly higher risk for ovarian cancer than those who had never been exposed to trauma. Women who experienced four-to-five symptoms were also at an elevated risk.
The Moffitt and Harvard study comes after an earlier study in Europe that found an association between PTSD and ovarian cancer in humans but that involved only seven patients. Funding for the new study came from a U.S. Department of Defense grant.
Women who have experienced PTSD shouldn’t panic, Tworoger said. If they have questions, they should talk to their doctor about it.
More resources about ovarian cancer can be found on the Centers For Disease Control And Prevention’s website.