|EMBARGOED FOR RELEASE
Tuesday, July 16, 2002
4:00 p.m. EDT
NCI Press Office
Increased Risk of Ovarian Cancer is Linked to Estrogen Replacement Therapy
- Duration vs. dose of estrogen therapy
It is not clear from this study whether the increased risk with estrogen use is due to higher doses of estrogen, longer duration of estrogen use, or both dose and duration. It is also not clear whether long-term use of lower-dose estrogen is associated with ovarian cancer.
- Duration of estrogen-progestin therapy
Most women in this study were on the combined therapy for less than four years, so more data will be needed to determine whether estrogen-progestin use increases risk. The effect of long-term use of estrogen-progestin therapy is not known.
- The type of estrogen-progestin regimen
The continuous regimen involves taking both hormones simultaneously throughout the month. The sequential regimen, on the other hand, involves taking estrogen every day, and progestin for 10 to 14 days each month.
- Use of more than one type of hormone replacement therapy
For instance, after taking estrogen alone, some women changed to a combined regimen after reports of increased endometrial cancer risk with estrogen alone. More data are needed to analyze the effect of switching from one regimen to another.
- The form of estrogen administration
Most studies have analyzed the use of estrogens in pill form, but it can also be administered by patches, shots, and creams.
Every year, about 23,000 U.S. women are diagnosed with ovarian cancer and 14,000 women die from the disease. A woman's lifetime risk of developing ovarian cancer is 1.7 percent. This means that in a group of 100 women followed from birth to age 85, fewer than two would get ovarian cancer. In comparison, about 13 women would get breast cancer (lifetime risk is 13.3 percent), fewer than three women would develop uterine cancer (lifetime risk is 2.7 percent), and between 16 and 32 women would develop osteoporosis.
An estimated 40 million U.S. women will experience menopause during the next 20 years, and women today are living approximately one-third of their life after menopause.
Anywhere from 20 percent to 45 percent of U.S. women take some form of hormone therapy between the ages of 50 and 75. According to industry estimates, about 8 million U.S. women use estrogen alone and about 6 million U.S. women use estrogen-progestin therapy. About 20 percent of hormone users continue for more than five years.
For background information on hormone replacement therapy: http://newscenter.cancer.gov/pressreleases/estrogenplus.html
For more information on recent studies on hormone therapy:
Call the NCI's Cancer Information Service for information about hormone replacement therapy and cancer risk. The number is 1-800-422-6237 (1-800-4-CANCER). For hearing impaired callers, TTY: 1-800-332-8615.
*The study is titled "Menopausal hormone replacement therapy and risk of ovarian cancer." The authors are James V. Lacey, Jr., Pamela J. Mink, Jay H. Lubin, Mark E. Sherman, Rebecca Troisi, Patricia Hartge, Arthur Schatzkin, and Catherine Schairer.