Hormone Therapy Raises Ovarian Cancer Risk
Study Shows an Increase in Risk for Estrogen-Only or Estrogen-Plus-Progestin Therapy
Ovarian Cancer and Hormones continued...
For those currently on hormone therapy, the risk of getting ovarian cancer didn't differ much among the various therapies, doses, or administration, Morch found.
''Ovarian cancer is among the most lethal of gynecologic cancers," Morch says. "The five-year survival rates are 40%." To complicate the issue, ovarian cancer is difficult to detect, and thus often not found until it is in advanced stages.
Previous research has found that current use of hormones raises ovarian cancer risk by 30% compared with no hormone use, with the risk of estrogen-only therapy sometimes found to be higher than combined therapy.
''This study supports an approximately similar increased risk for ovarian cancer disregarding the hormone type," she says.
This year, 21,550 new cases of ovarian cancer are expected in the U.S., with an estimated 14,600 deaths from the disease, according to American Cancer Society estimates.
"It's a well done study," says Andrew Li, MD, a gynecologic oncologist at Cedars-Sinai Medical Center, Los Angeles, who reviewed the study for WebMD. "Their findings are in line with what other people report," says Li, who is also an assistant clinical professor of obstetrics and gynecology at the University California Los Angeles' David Geffen School of Medicine.
Like most research, the study has limitations that may have affected the results, Li says, and the authors also acknowledge this. Among the limitations are that the researchers didn't adjust for age at menopause or use of birth control pills; birth control pill use and early natural menopause both reduce ovarian cancer risk.
The main contribution of the new study is to look at large numbers of women who took different types of hormone therapy and determine which type or types carry risk, says Shelley Tworoger, PhD, an assistant professor of medicine and epidemiology at the Harvard School of Medicine and School of Public Health, who has also published her research on hormone therapy and ovarian cancer risk. "The real contribution [of the new study] is that the combined regimen also increases the risk of ovarian cancer," she says. In her research, Tworoger found that estrogen-only therapy boosted risk and a suggestion of an increased risk with estrogen and progestin therapy.