Researchers have found bacteria in women's ovaries and fallopian tubes – locations previously believed to be sterile.
Different types of bacteria
The investigators also discovered that women with ovarian cancer have a different bacterial population in these locations than women without the cancer.
This finding raises the question of whether bacteria in the upper reproductive tract might play a role in the development or progression of ovarian cancer.
"This is a place essential to the beginning of life you don't expect that it's a place that's teeming with bacteria," Dr Wendy Brewster, director of the University of North Carolina Centre for Women's Health Research, said in a university news release.
"But there are bacteria in chemical pits at the bottom of the ocean, so why not in the fallopian tubes? Our proof of principle study has determined that while the upper female reproductive tract certainly isn't teeming with bacteria, there are bacteria present," Brewster said.
More research needed
The researchers took samples from the upper reproductive tract of 25 women. The women were already undergoing surgery to have their uterus, fallopian tubes or ovaries removed. Some of the women had cancer, while others did not.
Using genetic testing, the researchers identified the types of bacteria found in the samples. Different bacteria were found in the fallopian tubes than were found in the ovaries, the study revealed.
Women with ovarian cancer had more strains of potentially harmful bacteria, the researchers found. But it's too soon to know if these bacteria play a role in the development of ovarian cancer.
"Now that we know that these organisms are there, and that there are different organisms in different parts of the upper female reproductive tract, we want to know: Do these organisms influence whether or not you get cancer, or do they influence the behaviour of cancer? If you have different types of organisms, do you have better outcomes?" Brewster said.
More research is needed, the study authors suggested.
The study was presented at the American Society of Clinical Oncology annual meeting in Chicago. Findings presented at meetings are typically viewed as preliminary until they've been published in a peer-reviewed journal.