Breast Cancer Survival May Be Hurt by Guidelines on Mammograms, Data Show
By - May 2, 2011 1:00 AM ET
Women under 50 who follow the advice of a U.S. panel to forgo annual mammograms are risking more severe forms of breast cancer because of it, three studies led by radiologists suggest.
Failing to get regular breast screenings left women more likely to discover cancer at an advanced stage, retrospective research at hospitals in Ohio and Missouri found. The delay resulted in larger tumors and a worse prognosis once the cancer was uncovered, the data found. A study in Colorado suggests 62 percent of doctors changed their advice to match the U.S. guideline and 16 percent fewer women got the test.
The U.S. Preventive Services Task Force said in 2009 that most women ages 40 to 49 don’t need mammograms, restricting the test to those with a disease history or who had a greater risk for another factor. The American Cancer Society disputed the advice, and insurers still cover annual screenings.
“If you get a mammogram and a cancer is diagnosed, you are likely to have a better prognosis and a less toxic form of treatment,” said Donna Plecha, a radiologist at University Hospitals Case Medical Center in Cleveland, who analyzed biopsy results from Jan. 1, 2008, to Dec. 31, 2009. “If you don’t, you will have the opposite.”
The three studies were presented at separate medical meetings held today and Friday by theAmerican Society of Breast Surgeons in Washington and the American Roentgen Ray Society, representing radiologists, in Chicago.
40,000 Women Killed
Breast cancer killed an estimated 40,000 women last year and is the second leading cause of death among women, exceeded only by lung cancer, according to Atlanta-based Cancer Society. The group estimated that about 207,090 new cases of invasive breast cancer were diagnosed in 2010.
In issuing its recommendations, the federal task force said women in their 40s are more likely to get false-positive tests that lead to unnecessary biopsies and anxiety than to discover cancer through a mammogram. The guideline was challenged by the cancer society, which urged doctors to advise women of that age to continue routine annual screenings.
The independent task force, under the U.S. Agency for Healthcare Research and Quality, was first formed in the 1980s to give advice on screening, counseling and preventive medicines based on an assessment of scientific evidence. The panel has been known for its conservatism, said Therese B. Bevers, medical director of the Cancer Prevention Center at M.D. Anderson Cancer Center in Houston, when the guideline was issued in 2009.
30 Topics in Review
Academic and practicing doctors and nurses make up the group, according to the panel’swebsite. They have published guidelines on more than 100 topics and are reviewing 30 more, involving cervical cancer tests, dementia and glaucoma screening and the use of electrocardiographs for detection of coronary heart disease.
“Despite significant objections to the new guidelines, few researchers have specifically looked at mammography and its long-term impact on outcomes in younger women,” said Paul Dale, a study researcher and chief of surgical oncology at the Ellis Fischel Cancer Center at the University of Missouri School of Medicine, Columbia, about the breast cancer advisory.
Dale and colleagues analyzed breast cancer cases in women younger than 50 from 1998 to 2008. The study showed that 94 percent of the women ages 40 to 49 diagnosed through a mammogram were considered disease free after five years compared with 78 percent of those who didn’t receive the screening exams.
‘Important Information’
“This study provides important new information,” Dale said in a report issued at the Washingtonbreast surgeon meeting.
Plecha’s team studied biopsy results from Jan. 1, 2008, to Dec. 31, 2009. Seventy-one of 108 diagnosed breast cancer cases were detected by a mammogram and 37 resulted from discovery of a lump or other symptom. Twenty-two cases were non-invasive cancer in the tested group compared with one among those who were not.
None of the cancers in the mammogram group had progressed to latest stage form of the disease compared with 17 among those who weren’t screened.
More than half of the women who had a mammogram showed no evidence of cancer in their lymph nodes compared with 39 percent in the group that hadn’t been screened, Plecha said in a telephone interview. Her study also showed the size of the tumors to be on average smaller among the women whose cancer was discovered in a mammogram.
Lara Hardesty, a radiologist at the University of Colorado in Aurora, led a team that conducted an e-mail survey of primary care physicians and gynecologists at her institution to see if they changed their recommendations for women younger than 50 because of the Preventive Services Task Force advice.
Treatable Early
“The earlier we find cancer the more treatable it is and it’s my concern that, for some of them, we will be missing an opportunity for early diagnosis,” Hardesty said in a telephone interview. “I realize I am a radiologist and this is my livelihood, but I am also the one who has to tell a young woman she has breast cancer.”
In a separate study, Hardesty’s team compared the number of women in that age group who received mammograms in the nine months before and after the guidelines were issued. The researchers reported a 16 percent reduction in the number of screenings in the time period after the task force’s recommendations.
“We didn’t look to see how many cancers developed or how bad they were,” Hardesty said.
To contact the reporter on this story: Pat Wechsler in New York at pwechsler@bloomberg.net
To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net
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