Study adds support to mammograms starting at age 40

In the latest findings to fuel the debate on when to start getting mammograms, new research adds support to those suggesting that annual breast X-rays should begin at age 40.

Screening younger women has been controversial, with 2009 guidelines from a U.S. federal task force recommending against routine mammography screening for average-risk women in their 40s.

The new study showed that mammograms were just as likely to find invasive breast cancers in women with no family history of breast cancer as in women with a family history of the disease. Invasive breast cancer grows beyond the milk ducts or lobules of the breast.

The women in the study were aged 40 to 49.

And women with and without a family history were just as likely to have cancer that had spread to the lymph nodes, says study leader Stamatia Destounis, MD, a radiologist at Elizabeth Wende Breast Care, LLC, in Rochester, N.Y.

Women without a family history are "average-risk" women, suggesting that annual mammograms are indeed beneficial for this age group, she says.

A criticism of screening younger women is that "you find small cancers that will never be a problem. But we found a considerable number that can't wait," Destounis tells WebMD. "Invasive breast cancers can spread and kill."

The findings were presented here at the annual meeting of the Radiological Society of North America. Destounis receives funding to conduct clinical research from several breast imaging companies, including Siemens AG. But the current study was independently funded without company support.

Family History May Not Be Only Risk

More than 230,000 women will be diagnosed with breast cancer in the U.S. in 2011, more than 26,000 of whom will be under age 45, according to the American Cancer Society.

Destounis and colleagues reviewed the medical records of 1,071 women in their 40s who had screening mammograms at their medical center between 2000 and 2010. A total of 373 were diagnosed with breast cancer.

Sixty-one percent of the women with cancer did not have a family history of the disease, meaning they did not have mothers, sisters, grandmothers, or cousins who had breast cancer. Of these women, 64% had invasive breast cancer.

Similarly, 63% of women who did have a family history of breast cancer had invasive disease. Also, about 30% of women in both groups had cancer that had spread to the lymph nodes, the study showed.

The Mammograms Debate Rages On

The frequency of screening mammograms -- and the appropriate age to begin them -- has been debated since the U.S. Preventive Services Task Force in 2009 recommended that women routinely get screening mammograms every other year starting at age 50.

The task force says the decision to start regular mammograms before age 50 should be an individual choice based on each woman's situation. But overall, the benefit of screening all women in their 40s does not outweigh the risks, including that of having to undergo unnecessary biopsies, the task force says.

The American Cancer Society and the National Cancer Institute both continue to recommend annual screening beginning at age 40, however, leading to confusion among doctors and patients, Destounis says.

The new findings are unlikely to put an end to the debate, says Edith Perez, MD, a breast cancer specialist at the Mayo Clinic in Jacksonville, Fla.

What they do suggest, she tells WebMD, is that family history is not useful for deciding which younger women would benefit from annual screening mammograms.

Screening recommendations are aimed at the general population, not the individual patient, says Claudine Isaacs, MD, director of the clinical breast cancer program at Georgetown's Lombardi Comprehensive Cancer Center in Washington, D.C.

"This is an area of considerable controversy and, as always, it is best for women to check with their own doctors," she tells WebMD.