Women who experienced 6 or more post-traumatic stress disorder (PTSD) symptoms were twice as likely to develop ovarian cancer compared with women who had never had any PTSD symptoms, according to a new study by the Harvard T.H. Chan School of Public Health and Moffitt Cancer Center.

The findings indicate that higher levels of PTSD symptoms, such as being easily startled by ordinary noises or avoiding reminders of traumatic experiences, can be associated with increased risks of ovarian cancer even decades after women experience a traumatic event, according to the study authors.

The study, published in Cancer Research, used data from the Nurses’ Health Study II, a longitudinal cohort study with approximately 54,710 participants conducted from 1989 to 2015 with 26 years of follow-up. Women were asked to identify the event they considered the most stressful and the year of this event. They were also asked about 7 PTSD symptoms they may have experienced related to this event.

Based on the responses, women were divided into 6 groups: no trauma exposure; trauma and no PTSD symptoms; trauma and 1 to 3 symptoms; trauma and 4 to 5 symptoms; trauma and 6 to 7 symptoms; and trauma, but PTSD symptoms unknown.

Researchers examined the risk of ovarian cancer that occurred after an initial PTSD assessment in 2008 and subsequent associations based on menopausal status. During their follow-up, they identified approximately 110 ovarian cancer cases, and found that women with higher PTSD symptoms had twice of a greater risk of ovarian cancer compared with women with no trauma exposure.

More specifically, the researchers found that women who experienced 6 to 7 symptoms associated with PTSD had a significantly higher risk for ovarian cancer than women who had never been exposed to trauma. Women with trauma and 4 to 5 symptoms were also at an elevated risk, but it did not reach statistical significance.

In women ages 35 to 74 years old, ovarian cancer is the fifth leading cause of cancer-related deaths, with 1 in 78 women developing the disease in her lifetime. The American Cancer Society estimates that there will be more than 22,280 new cases of ovarian cancer diagnosed this year and that more than 14,240 women will die from ovarian cancer this year.2

The study authors noted that better understanding of the underlying molecular mechanisms could lead to interventions that reduce ovarian cancer risk in women with PTSD and other stress-related mental disorders.

Reference
  1. Roberts A, Huang T, Koenen K, et al. “Posttraumatic stress disorder (PTSD) is associated with increased risk of ovarian cancer: a prospective and retrospective longitudinal cohort study.” Cancer Research. DOI: 10.1158/0008-5472.CAN-19-1222. Published September 5, 2019. https://cancerres.aacrjournals.org/content/early/2019/09/04/0008-5472.CAN-19-1222. Accessed September 5, 2019.
  2. What is Ovarian Cancer? National Ovarian Cancer Coalition website. http://ovarian.org/about-ovarian-cancer/what-is-ovarian-cancer. Accessed September 5, 2019.
  3. PTSD linked to increased risk of ovarian cancer [press release]. Harvard TH Chan website. Published September 5, 2019. https://www.hsph.harvard.edu/news/press-releases/ptsd-linked-to-increased-risk-of-ovarian-cancer/. Accessed September 5, 2019.