Common Cause of Female Infertility and Ovarian Cancer
Fertility and Infertility News
Obie Editorial Team
By Sandy Hemphill, Contributing Writer, BabyMed
According to the US National Cancer Institute, more American women die from ovarian cancer than from any other form of cancer originating in the female reproductive tract. There’s a well-known association between infertility and ovarian cancer but no definitive evidence that one condition causes the other. A recent large British study indicates there may not be a cause-and-effect association but a common cause instead that leads to both infertility and ovarian cancer.
Like many cancers, ovarian cancer is actually a blanket term describing several forms of cancer that originate in the ovaries. Four tumor types are most common (clear cell, endometrioid, mucinous, and serous) and each type is associated with a specific pattern of childbearing:
Tubal ligation (severing the fallopian tubes for contraceptive purposes) has an effect, too:
The British study did not strive to learn how, exactly, tubal ligation reduces the risk of ovarian cancer but suggests the severing of the fallopian tubes may form a barrier that prevents abnormal (pre-cancerous) cells from traveling to the ovaries.
Long-term breastfeeding (six months or longer) is associated with a lowered risk of ovarian cancer, too, with the risk factor lowering with each six-month period of breastfeeding.
One significant finding of the study, led by Dr. Kezia Gaitskell, a pathologist at the University of Oxford’s Cancer Epidemiology Unit, is that “known risk factors for ovarian cancer, such as childbirth and fertility, vary between the different tumor types.” She adds that revolutionary research in recent years proves that ovarian cancer doesn’t always start in the ovaries. High-grade serous tumors start in the fallopian tubes and some clear cell and endometrioid tumors develop only in women with endometriosis.
Endometriosis provides a good example of infertility and ovarian cancer sharing a common cause rather than being a cause-and-effect situation. Endometriosis is diagnosed when the endometrium (tissue lining the uterus) grows outside the uterus, making conception and pregnancy difficult. Endometrioid tumors develop in the endometrium regardless of whether this uterine tissue is situated inside or outside the uterus. The two conditions — infertility caused by endometriosis and cancerous endometrioid tumors — both share common origins in the endometrial tissue.
Gaitskell’s study, funded by Cancer Research UK, involved analysis of medical data from 1,146,985 women whose average age was 56 at the time they enrolled in the study. During the lengthy study, 7,570 participants developed ovarian cancer. The ovarian cancer diagnoses came an average of 13 years after enrollment in the study.
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