Having Children Tied to Lower Ovarian Cancer Risk
Women who've had their tubes tied also seemed to be protected
TUESDAY, Nov. 3, 2015 (HealthDay News) -- The more children a woman has, the lower her risk of ovarian cancer may be, a new study suggests.
The study also found that the risk is lower in women whose fallopian tubes have been tied -- a procedure called tubal ligation.
British researchers analyzed data from more than 8,000 women to determine risk factors for the four most common types of ovarian cancer: serous, mucinous, endometrioid and clear cell tumors.
"In the last few years, our understanding of ovarian cancer has been revolutionized by research showing that many cases may not in fact come from the ovaries. For example, many high-grade serous tumors -- the most common type -- seem to start in the fallopian tubes, while some endometrioid and clear cell tumours may develop from endometriosis," lead researcher Kezia Gaitskell said in a Cancer Research U.K. news release.
Compared to women with no children, those with one child had a 20 percent lower overall risk of ovarian cancer and a 40 percent lower risk of endometrioid and clear cell tumors. Each additional child offered an additional 8 percent reduction in overall ovarian cancer risk, said Gaitskell, who is a pathologist in the University of Oxford's Cancer Epidemiology Unit.
Further investigation showed that women whose fallopian tubes had been tied had a 20 percent lower overall risk of ovarian cancer; a 20 percent lower risk for high-grade serous tumors; and a 50 percent lower risk for endometrioid and clear cell tumors.
The study was to be presented Tuesday at a meeting of the U.K.'s National Cancer Research Institute, in Liverpool. Research presented at meetings is typically considered preliminary because it is not subject to the same scrutiny as studies published in medical journals.
It should be noted that the study uncovered a link, but not a cause-and-effect connection, between the number of children a woman has and her risk of ovarian cancer.
The increased risk among women with no children is believed to be related to infertility. Gaitskell noted that some conditions -- such as endometriosis -- that make it harder for a woman to get pregnant may also increase her risk for specific types of ovarian cancer.