Examining the Link Between Hormone Therapy and Ovarian Cancer

July 19, 2009 07:00 AM
by findingDulcinea Staff
A study indicates that hormone replacement therapy increases the risk of ovarian cancer by 38 percent. Hormone therapy has been declining significantly since 2002, when a major study linked it to increased risk of breast and ovarian cancer, and heart problems.

Study Finds Hormone Therapy Increases Risk of Ovarian Cancer

A Danish study has found that menopausal women who took hormone replacement therapy had a 38 percent greater risk of contracting ovarian cancer than women who did not take hormone therapy.

The risk increase is not as considerable as 38 percent may suggest. “Put another way: for every 8,300 women on hormone therapy per year, one extra case of ovarian cancer could be attributed to hormone therapy,” explains WebMD.

The risk did not differ substantially based on the kind of therapy, the dose or the duration of use. “The study suggests that no type of hormone seems safe regarding the risk of ovarian cancer,” said Lina Steinrud Morch, the study’s lead author, to Bloomberg.
The study reinforces previous findings that linked hormone therapy to an increased risk of cancer. In 2002, a study by the Women’s Health Initiative involving hormone therapy was stopped after researchers saw a higher risk of breast cancer and heart trouble. Since then, there has been a significant drop in hormone therapy.

Dr. Corrado Altomare, senior director of global medical affairs for Wyeth Pharmaceuticals, the producer of combined estrogen-progestin therapy Prempro, told WebMD, “This finding doesn't really change what we know. We actually have a warning in our label about ovarian cancer.”

Opinion & Analysis: Accessing the risk of hormone therapy

Dr. Andrew M. Kaunitz, writing in Journal Watch, cautions against drawing wide-ranging conclusions from the study. The causal nature of the link between hormone therapy and cancer is “uncertain,” he writes, adding, “weak associations in observational studies can result from detection bias.”

U.S. News & World Report’s Deborah Kotz examines how women should react to the findings. In an e-mail, Morch told her, “Ovarian cancer is highly fatal, so accordingly this risk warrants consideration when deciding whether to use HT.”

Isaac Schiff, chief of obstetrics and gynecology at Massachusetts General Hospital in Boston, told Kotz that the finding would not change the way he approaches hormone therapy. While he warns his patients of the increased risk of breast cancer, he believes that only women with a family history of ovarian cancer should be concerned about the risks of hormone therapy.

Kaunitz takes a similar approach; “whether these findings should be used to counsel women who are weighing the pros and cons of HT is not clear,” he concludes.

Background: Increased risk of breast cancer and heart problems

In the years leading up to 2002, several studies found that hormone therapy could increase the risk for cancer. Those findings were driven home in July 2002, when the Women's Health Initiative abruptly ended its study of 16,000 women after finding that women taking estrogen and progesterone had a 26 percent higher risk of breast cancer, as well as an increased risk of heart attack stroke and blood clots.

Following the news, doctors were recommended to prescribe the lowest-possible dose of hormones and only to alleviate the most severe of symptoms associated with menopause.

A Women’s Health Initiative Study released in December 2008 found that hormone therapy dropped 41 percent in 2003 and dropped 70 percent by 2008. During the same period that fewer women took hormones, the incidence of breast cancer also dropped.

That study, revealed at the San Antonio Breast Cancer Symposium, found that taking estrogen and progestin for several years increased the risk of breast cancer, while taking hormone therapy pills for five years doubled the risk for breast cancer.

“Collectively, these new findings are likely to end any doubt that the risks outweigh the benefits for most women,” The Associated Press said.

But another study presented at the symposium suggests that women who develop breast cancer after taking hormone replacement therapy “have a lower risk of dying from the disease,” HealthDay reported.

“We found that women who took hormone therapy before their diagnosis were more likely to be diagnosed with estrogen receptor-positive cancer, as well as having breast cancers that were more favorable in other ways, [such as being] smaller and detected at an earlier stage,” said Sarah Marshall, a senior statistician at University of California-Irvine and one of the study’s authors, according to HealthDay.

Reference: Breast cancer, menopause


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