Researchers from Oxford University found that women whose fallopian tubes were cut during tubal ligation (sterilization) have lower risks of developing ovarian cancers. This could probably be due to the fact that some ovarian cancers develop in the fallopian tubes.
Ovarian cancer is the 5th most common cancer among women. The four types of ovarian cancers involve clear cell, endometrioid, mucinous and serous tumors. Past studies showed women with children have lower risk for acquiring ovarian cancer. The new research looked into the association of childbirth, fertility and sterilization to a woman's risk of developing any of the four main types of ovarian cancer.
The team analyzed approximately 7,100 women with ovarian cancer in the United Kingdom (UK). Researchers found that women with one child have a 20 percent decrease in developing any type of ovarian cancer compared to women who did not bear children. There is also a 40 percent decrease in the risk of developing clear cell and endometrioid tumors. It gets better because with each child comes another estimated eight percent decrease in the general risk of developing ovarian cancer.
There's more. Women who had their fallopian tubes cut have 20 percent decrease in the overall risk of developing the disease compared to women who chose not to take the surgery. The risk for developing high-grade serous tumors is also 20 percent lower for these women. Lastly, sterilized women have 50 percent reduced risk in developing clear cell and endometrioid tumors.
Oxford University's scientist Dr. Kezia Gaitskell expressed that new understanding of ovarian cancer has been propelled by research that reveal many cases do not stem from the ovaries. A good example is the development of several high-grade serous tumors which stem from the fallopian tubes. Another is the development of some clear cell tumors and endometrioid which could stem from endometriosis.
"We think that the significant reduction in risk among women with one child compared to women without children is likely to be related to infertility, as there are some conditions - such as endometriosis - that may make it harder for a woman to become pregnant, and which may also increase her risk of these specific types of ovarian cancer," said Gaitskell.
The study was presented at the Liverpool cancer conference of the National Cancer Research Institute (NCRI).