The study's results determined that women suffering from chronic chlamydia infections "had twice the risk of ovarian cancer compared to women with no evidence of ever having been infected."
According to Britton Trabert from the National Cancer Institute, data from the study implies that pelvic inflammatory disease is linked to ovarian cancer. In fact, in the U.S. chlamydia infection is the main cause of the disease. She added, "We are seeing a doubling in ovarian cancer risk with a prior history of pelvic inflammatory disease."
Even though ovarian cancer is relatively uncommon, in 2018 at least 21,000 American women will be diagnosed with it and it will kill over 14,000 patients. Ovarian cancer is the fifth leading cause of cancer deaths in women, and in five years it will kill 55 percent of patients. (Related: Apigenin Phytonutrient Cuts Ovarian Cancer Risk.)
On the other hand, chlamydia is a very common sexually transmitted disease (STD). As per the Centers for Disease Control and Prevention (CDC), over 1.5 million Americans have chlamydia.
While antibiotics can treat the STD, patients don't usually experience any symptoms, making it difficult to diagnose. People with chlamydia are often unaware that they have it, and they can be infected for months or years. If left untreated, chlamydia will cause widespread inflammation that can lead to infertility.
The study's results suggest that the STD can also cause cancer. However, the researchers weren't able to test for gonorrhea, another common STD that causes pelvic inflammatory disease.
The doubled risk doesn't substantially increase the number of cases, but except for genetics, only a handful of causes have been confirmed. The most well-known risk factor for ovarian cancer is having a family history of the disease. Yet in most cases, the women didn't have a known family history of ovarian cancer. Women with endometriosis, or the overgrowth of the uterine lining, have a higher risk of ovarian cancer.
Even screening for ovarian cancer can be complicated since the disease has vague symptoms such as bloating, which can be caused by something as common as eating a heavy meal. Trabert explained that further research will help confirm if immediately treating chlamydia minimizes the risk of cancer and if confirming the infection does raise the risk in the first place.
The research team examined two separate studies. The first was done in Poland, which analyzed 278 ovarian cancer cases and 556 female participants without cancer.
The second was a U.S. study that compared data from 160 ovarian cancer patients and 159 cancer-free participants. Researchers tested the blood samples of the patients for an antibody that indicated when an individual has been infected with chlamydia.
For both studies, women with evidence of previous chlamydia infection had a 50-percent risk of being part of the ovarian cancer group. Women who had antibodies against other infections like herpes or hepatitis had a lower risk of having the disease. The women infected with human papillomavirus (HPV), which can cause other types of cancer, did not have a higher risk of ovarian cancer.
You can read more articles about how to prevent STDs and ovarian cancer at WomensHealth.news.
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