A new Fred Hutchinson Cancer Center study in the journal Obstetrics & Gynecology investigated how endometriosis, uterine leiomyomas (also known as fibroids) and a common intervention for these conditions—hysterectomy—changed ovarian cancer risk in Black and white women.

Scientists found fibroids were associated with an increased risk of ovarian cancer in both Black and white women, with hysterectomy modifying the risk of cancer in both groups. However, researchers also found that while Black and white women with endometriosis had a higher risk of ovarian cancer overall, hysterectomy only modified this risk of cancer for white women.

“Almost no research has been done examining the experiences of Black women with endometriosis, including how endometriosis can heighten the risk for ovarian cancer,” said Fred Hutch epidemiologist Dr. Holly Harris, who led the study. “We need to continue making more discoveries in this area and conduct further research into how variables such as medical interventions as well as access to care and treatment also impact the risk of ovarian cancer in all populations.”

The study’s primary goal was understanding how racial differences impacted ovarian cancer risk—an under-studied area of research particularly impacting Black women. Data from the Ovarian Cancer in Women of African Ancestry Consortium (OCWAA) was utilized to compare outcomes from both Black and white women impacted by endometriosis and/or fibroids and the variety of medical interventions typically used to treat these conditions.

“Conditions such as endometriosis and fibroids can impact health and quality of life,” said Dr. Barbara Norquist, a Fred Hutch clinician focusing on gynaecological oncology. “Medical interventions, such as hysterectomies, used to treat these conditions can have an impact on future health outcomes. This study is an important step toward understanding these outcomes and better understanding ovarian cancer risk.”

Nearly 5,500 women took part in the study. The study included 3,124 Black women of which 1,008 had ovarian cancer and 5,458 white women of which 2,237 had ovarian cancer. Of the study participants, 6.4% of Black women and 7% of white women experienced endometriosis and 43.2% of Black women and 21.5% of white women experiencing fibroids.

The National Cancer Institute, estimated 236,511 women in the U.S. were living with ovarian cancer in 2020, and the American Cancer Society notes that it is the fifth leading cause of cancer death in women.

“Like many other diseases of reproductive health, endometriosis and fibroids research is severely underfunded in proportion to their population burden,” said Dr. Elizabeth Swisher, who serves as a co-leader of Fred Hutch/University of Washington/Seattle Children’s Cancer Consortium Breast and Ovarian Cancer Research Program. “Because of this, our knowledge of these diseases is severely limited, leaving patients with sub-par treatments and substantial impacts on their quality of life.”

Researchers hope to continue looking at how racial differences impact ovarian cancer risk, as well as the role that endometriosis and fibroids play.

“Despite the lower occurrence of ovarian cancer in Black women, this group has the highest mortality from ovarian cancer. Identifying how racial differences in access to care and treatment impact this disparity is critical to formulating risk reduction strategies,” said Dr. Harris.

Source: Fred Hutchinson Cancer Center