The American Cancer Society now recommends that women wait to begin annual mammograms until age 45 rather than 40, advice that conflicts with other recommendations, leading some to worry that it will confuse women who might need the test.
While several professional societies continue to recommend annual tests starting at age 40, the U.S. Preventive Task Force recommends biennial exams beginning at age 50.
The newest advice released Tuesday prompted a sharp reaction from some experts and advocates who fear it could prompt women to put off mammograms used to detect breast cancer, the most common cancer found in women, which kills about 40,000 a year in the United States.
"We've spent years telling women to come get mammograms on a regular basis, and this [new recommendation] makes me crazy," said Dr. Michael Schultz, a breast cancer surgeon and medical director of the breast center at the University of Maryland St. Joseph Medical Center. "It's confusing enough for women."
The cancer society's recommendation prompted Sen. Barbara A. Mikulski, a Maryland Democrat, to renew her call Tuesday for a bill she introduced in August to protect women's access to mammograms starting at age 40.
"Women's access to free preventive mammograms must not be impeded, discouraged or eliminated," Mikulski said.
The cancer society based its new recommendation, published in the Journal of the American Medical Association, on an extensive review of studies that do not find added benefit in general from universal screening at 40. It also said that mammography is imperfect and sometimes produces anxiety-inducing false alarms, leading to costly and unnecessary biopsies and other tests.
The group did say there ought to be flexibility to allow for mammograms at 40.
Schultz and other doctors contend the technology has improved, producing fewer questionable results. Also, they say doctors do not generally know which tumors will go on to cause trouble, so most are still treated, and finding cancer earlier generally makes that easier.
He said the society's advice is not "one size fits all," noting the fine print about the need for flexibility in the recommendation. Doctors and patients need to consider family history, genetic and other risk factors.
To find out when you need a mammogram, "go talk to your doctor," he said.
About 200,000 women are diagnosed each year with breast cancer in the United States, and about 11 percent are younger than 45, according to the Centers for Disease Control and Prevention.
The American College of Radiology, the American Congress of Obstetricians and Gynecologists, and other professional societies, as well as doctors who routinely perform mammograms, still advocate for mammograms beginning at age 40, including Dr. Syed H. Husain, vice chairman of the department of radiology at Saint Agnes Hospital in Baltimore and director of women's imaging at the Saint Agnes Comprehensive Breast Center.
So does Dr. Lyn Ho, an assistant professor of diagnostic radiology at the University of Maryland School of Medicine and diagnostic radiologist at the University of Maryland Medical Center.
Ho said about 10 percent of her patients are called back for more tests after a mammogram shows a possible tumor. Most get more screening, and some get more detailed ultrasounds. About 2 percent have a needle biopsy and perhaps five in 1,000 are diagnosed with cancer, she said.
She acknowledged the anxiety produced by a call for further tests but said studies show that the rate of false alarms continues to go down with better technology such as tomosynthesis, also called 3-D mammography, which was approved in 2011 and takes breast images from many more angles.
"The anxiety is really short-term, because usually a few more images clears up any questions," Ho said. "If the results are positive, then we've usually succeeded in catching cancer early and making an impact on their quality of life."
Advocates for mammograms such as the Susan G. Komen organization do not want women to avoid talking to their doctors because of the new guidelines or fears that a mammogram will produce a false positive.
The group funds research into better technology, but officials there said that for now, mammograms remain the "best available tool for detecting breast cancer."
"Women and their health care providers should decide when those screenings should begin for individuals," said Dr. Judy Salerno, Komen president and CEO.
Komen and others do not want to see insurers back off from covering tests.
That is why Mikulski pushed for an amendment to the Affordable Care Act mandating coverage of mammograms and other preventive tests. The health reform law requires insurers to cover such preventive tests if they are recommended by the U.S. Preventive Task Force, an independent advisory panel.
But the task force recently reaffirmed its draft recommendation for testing every two years beginning at 50, so Mikulski introduced a new bill in August, along with Sen. Kelly Ayotte, a New Hampshire Republican, to require continued coverage for preventive mammograms at age 40 for two years, until the guidelines can be evaluated.
"Too many women are getting mixed messages when it comes to their health," Mikulski said. "That's why I've introduced bipartisan legislation that protects access to free preventive care mammograms for all women age 40 and older."
If it was up to Phyllis Wade of Waldorf, who was diagnosed in 1984 at age 28, every women would be screened in some way, through mammograms or clinical exams by a professional.
Professional exams, where a doctor feels the breast for lumps, and self-exams, are no longer recommended by the cancer society. The preventive task force also recommends against self-exams and says the evidence is inconclusive that clinical exams are beneficial.
This is particularly upsetting to Wade, who found a pea-size lump during a self-exam. She had learned from her doctor how to do one.
She waited three months to see if the lump would go away, but when it didn't she made an appointment with her gynecologist and had a mammogram, which confirmed a tumor. It was stage two, when the cancer still is contained in the breast and lymph nodes.
She had her right breast removed and is now cancer-free, though she gets checked every year.
"It's a big mistake to scale back," Wade said. "I never thought it would turn out to be cancer for me. I had no family history. I'm worried women will be put off by the new guidelines. And I think that will cost a lot of lives."