Menstrual Periods: Clues to Ovarian Cancer
Study Shows Risk of Death From Ovarian Cancer Linked to Overall Number of Ovulatory Cycles
July 9, 2009 -- A woman's hormonal activity over her lifetime affects her risk of dying from ovarian cancer, according to a new study.
''From this study, it looks like having a higher number of lifetime ovulatory cycles and starting your period earlier, at a younger age, increase your risk of death after a diagnosis of ovarian cancer," says Cheryl L. Robbins, PhD, an epidemiologist at the CDC's division of reproductive health and the study's lead author.
Women who have been pregnant, for instance, have fewer ovulatory cycles over a lifetime than those who have not been pregnant.
This year, 21,550 new cases of ovarian cancer are expected in the U.S., and an estimated 14,600 women will die from the disease, according to the American Cancer Society.
Ovarian cancer is difficult to detect in early stages; only a fifth of all cases are detected when the cancer is still localized. Symptoms can include those often associated with less severe problems, such as abdominal bloating or swelling, urinary urgency, and pelvic pain -- and are thus often overlooked by women.
While previous research has focused on risk factors for getting ovarian cancer -- including advancing age, obesity, and never becoming pregnant -- much less research has looked at risk factors that predict death once a diagnosis is made, Robbins tells WebMD.
For her study, she conducted an analysis of 410 women, ages 20 to 54, who were diagnosed with ovarian cancer and enrolled in the 1980-1982 Cancer and Steroid Hormone (CASH) study. After a follow-up with a median of 9.2 years (half followed longer, half less), 212 women died; 169 deaths were recorded as due to ovarian cancer.
Overall, the 15-year survival was 48% among the women study participants. Robbins and her team then looked at a host of reproductive factors including the number of pregnancies, use of oral contraceptives, breastfeeding history, age at first menstruation, whether the women had undergone hysterectomy, or whether they had their tubes tied.
The only reproductive factors that were statistically significant as predictors of dying from ovarian cancer were age at menstruation and the number of ovulatory cycles.
Those who had their first period before age 12 were 51% more likely to die from ovarian cancer compared to those who had their first period at age 14 or later.
In recent years, the age of first period has declined, Robbins and other say. For instance, Wright State University researchers recently found that girls born in the 1980s had an average age of 12.3 years when they had their first period. The study is published in the American Journal of Human Biology.
Women with the highest number of lifetime ovulatory cycles were 67% more likely to die of ovarian cancer than those in the group with the lowest number of cycles.
The study is published in Cancer Epidemiology, Biomarkers & Prevention.