To conduct their study, researchers studied the menstrual cycles of 14,000 women and discovered that those with irregular periods at age 26 were about twice as likely to die from ovarian cancer in their 60s as women with regular cycles. The researchers classified menstrual cycles as irregular if they lasted more than 35 days (typically, cycles last 21 to 35 days) or if ovulation did not occur.
These findings held up even when researchers took into account other factors that might increase a woman’s risk of ovarian cancer, including age, weight, use of fertility drugs, and birth control pills. Their research also ruled out infertility as an explanation for their findings, since all of the women in the study had given birth to at least one child.
It’s still unknown why irregular menstrual cycles might increase the risk of dying from ovarian cancer, but it’s possible that hormones play a role. The ovaries in these women may be exposed to lower amounts of progesterone, which is released during ovulation and may offer some protection against the deadly disease.
Study researcher Barbara Cohn, director of Child Health and Development Studies at the Public Health Institute in Berkeley, California, says it’s unfortunate that there’s no reliable way to screen for ovarian cancer, or diagnose it early. The typical symptoms of ovarian cancer, including abdominal pain and bloating, usually don’t come to a woman’s attention until the cancer has spread. But she adds that she believes the study’s findings may help with earlier diagnosis and “perhaps lead to a strategy to prevent ovarian cancer.”
