Half of U.S. women ages 40 or older failed to get an annual mammogram for breast cancer last year, said researchers concerned that women are confused by the debate about the effectiveness of the screenings.
The study, sponsored by Medco Health Solutions Inc., reviewed records for 1.56 million patients from January 2006 through December 2009. About 207,000 new cases of invasive breast cancer in women will be diagnosed and almost 40,000 women will die from the disease this year, according to the Atlanta-based American Cancer Society.
As death rates from the disease decreased over the last 10 years, the debate over how frequently to get a mammogram has grown. The cancer society recommends that women ages 40 or older get screened every year. In November 2009, the U.S. Preventive Services Task Force advised women 50 or older to undergo a mammogram only once every two years, and patients younger than 50 to get one only if they carry risk factors for the disease.
“As controversy becomes public and there’s so much back-and-forth, it becomes confusing for women,” said Milayna Subar, lead author of the study reported today at the San Antonio Breast Cancer Symposium, in a telephone interview. “This study shows the need to put programs in place to educate women and remind them to do it.”
Medco, based in Franklin Lakes, New Jersey, is the largest U.S. pharmacy benefit manager by number of prescriptions. Subar, a physician, heads the company’s Oncology Therapeutic Resource Center, which seeks ways to suggest health improvement for members of the health plans it serves.
The mammogram research was among studies presented today including new findings on the use of hormone therapy, and on the risk of death for obese women with a type of breast cancer.
Mammography has been shown to reduce death rates 20 percent to 30 percent among women 40 or older, according to the National Quality Measures Clearinghouse, an agency under the U.S. Department of Health and Human Services. The decrease stemmed from earlier detection through screening and from improved treatment, the cancer society has said.
Sixty-five percent of the study’s 708,290 women ages 50 to 64 -- considered the “must-do group” -- had a mammogram at least twice during the four-year period, Subar said.
“That still leaves 35 percent not getting mammograms even every other year,” she said. Fifty-seven percent of the 406,746 women ages 40 to 49 had a mammogram on average at least twice during the four-year period, and 47 percent had one screening on average every year.
Estrogen and Cancer
In a second study presented today at the San Antonio symposium, researchers reported that giving estrogen alone to older women who don’t have a uterus may reduce rather than increase their risk of breast cancer.
The study found a 20 percent reduction in breast cancer for older women who took estrogen alone, compared with a placebo, for postmenopausal hormone therapy. The study, from scientists who re-examined data from the Women’s Health Initiative trial, looked only at women who didn’t have a uterus.
Millions of patients had already stopped taking hormone replacement therapy after 2002 when the Women’s Health Initiative found a higher risk of breast cancer in postmenopausal women getting hormone treatment with both estrogen and progestin. The trend of avoiding estrogen-only treatment needs to be reversed, said Joseph Ragaz, the lead researcher for the new analysis.
Thousands of Lives
“We will be saving thousands of lives every year if we use hormone replacement therapy for menopause,” said Ragaz, a medical oncologist and a clinical professor at the University of British Columbia in Vancouver. “Women will not only have quality of life improvement by handling menopause more easily, they will also have substantial benefits on bone fractures, colon cancer and now breast cancer.”
Ragaz said estrogen-alone therapy should be given only to women who don’t have a uterus, because the hormone raises the risk of uterine cancer. Women who have undergone surgery to remove their uterus, called a hysterectomy, are typically candidates for estrogen-only therapy.
Ragaz and other researchers looked at 10,739 women without a uterus who were part of the estrogen-only trial of the Women’s Health Initiative. Half received a placebo and the other half, the drug Premarin, made by Pfizer Inc.’s Wyeth unit.
While women getting estrogen showed a 20 percent lower risk of breast cancer, the reduction was 30 percent to 40 percent in patients who had a low risk at the start of the study, Ragaz said. Those included women with no strong family history of breast malignancy.
Adds to Research
The analysis adds to research suggesting estrogen alone can lower breast cancer risk and that the hormone may have a place for treating menopausal symptoms, said JoAnn Manson, a principal investigator for the Women’s Health Initiative, a 15-year program organized by the U.S. National Institutes of Health.
“Estrogen still has a clinical role in the management of moderate to severe hot flashes and other menopause symptoms, especially in women who are closer to the onset of menopause,” said Manson, chief of the Division of Preventive Medicine at Brigham & Women’s Hospital in Boston and a professor at Harvard University.
Another study presented today at the San Antonio meeting found that women who are obese and have a type of breast cancer fueled by estrogen are more likely to die of the disease than their slimmer peers.
Adult women with body mass indexes of 30 or above are 42 percent more likely to die of estrogen-receptor positive/HER-2 negative disease, the study found. Two-thirds of all breast cancers are fed by estrogen, according to the National Institutes of Health.
Today’s study suggests that breast cancer patients who are already overweight or obese should make an effort to avoid further weight gain, said study author Joseph Sparano, the associate chairman of the oncology department at Montefiore Medical Center.
“We may need to pay greater attention to nutrition, and include a nutritional evaluation for someone who has breast cancer,” said Sparano, who is also a professor of medicine at the Albert Einstein College of Medicine, in a telephone interview.
Body mass index, or BMI, is a measure of weight and height, with a 5-foot 4-inch woman weighing 175 pounds having a BMI of 30. BMI of 30 or more is considered obese, while a BMI of 25 to 29.9 is considered overweight, according to the National Institutes of Health.
Third of Population
About a third of the U.S. adult population is obese, according to the Atlanta-based Centers for Disease Control and Prevention.
The study examined 3,484 people, of which 2,115 had breast cancer that was hormone-receptor positive, HER2-negative. HER2-negative cancer doesn’t produce a protein called HER2, which is a sign of a type of aggressive breast cancer generally treated with Roche Holding AG’s Herceptin.
It may be that obese women have more estrogen, since fat cells play a role in synthesizing it, Sparano said. It may also be related to insulin levels, since higher levels of the hormone have also been associated with increased breast cancer risk, he said.