Chlamydia Linked to Increased Ovarian Cancer Risk

Women who were previously diagnosed with chlamydia may have double the risk of ovarian cancer, even if they received treatment for the sexually transmitted infection (STI), according to a media preview for the American Association for Cancer Research annual meeting.

“Ovarian cancer is a relatively rare cancer, but women who get it face poor survival rates,” lead author Britton Trabert, PhD, MS, said in a press release. “We need to understand more about what causes ovarian cancer so that we can improve screening and treatment, and ultimately, improve survival rates.”

Previous studies have shown that pelvic inflammatory disorder—which can be caused by STIs—can lead to ovarian cancer; however, other studies have failed to find a connection between STIs and ovarian cancer.

In the new study, the authors specifically looked at the occurrence of chlamydia and ovarian cancer. They examined data from a study of 278 Polish women diagnosed with ovarian cancer between 2000 and 2003 and 556 controls. Also in the new analysis were data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, which included 160 women who developed ovarian cancer and 159 controls.

The researchers discovered that women who had antibodies against pgp3—an indicator of active or prior chlamydia infection—were twice as likely to develop ovarian cancer, according to the study.

The analysis also explored the link between ovarian cancer and antibodies against human papillomavirus, herpes simplex virus, hepatitis B virus, and hepatitis C virus. They did not discover a link between the viruses and increased ovarian cancer risk, according to the study.

“The fact that there were no associations with antibodies against other infectious agents really supports the specificity of the association of chlamydia infection with ovarian cancer,” Dr Trabet said.

The researchers said that the next step is to confirm the findings in a larger population and determine whether the STI is linked to certain subtypes of ovarian cancer.

If confirmed, these findings have serious implications for Americans. The CDC recently reported that there were more than 2 million cases of STIs recorded in 2016. The annual report indicated that chlamydia dominated new diagnoses, accounting for 1.6 million cases in 2016, according to the CDC. The agency reported that chlamydia is most prevalent among younger women.