New Screening Mammography Guidelines Affect Women in Their Forties

< Apr. 04, 2007 > -- Not all women in their 40s should be routinely screened for breast cancer, says the American College of Physicians (ACP).

New mammography guidelines issued by the ACP for women 40 to 49 years old suggest that any decision to undergo the exam should be based on a discussion between a woman and her physician.

The ACP is one of several medical groups that have put forward ideal intervals for mammography screenings for breast cancer. However, there is no consensus among the groups for women in their 40s.

For example, the American Cancer Society (ACS) recommends annual mammograms for women beginning at age 40. The National Cancer Institute (NCI) recommends that women in their 40s and older should have a screening mammogram on a regular basis, every one to two years. And the US Preventive Services Task Force recommends screening mammography every one to two years for women 40 and older, noting there was not enough evidence to specify the best screening interval for women 40 to 49.

Breast cancer is the most common cancer among women, other than skin cancer. It is the second-leading cause of cancer death in women, after lung cancer. An estimated 178,000 women in the US will be diagnosed with invasive breast cancer in 2007, and about 40,000 women will die from the disease this year, according to the American Cancer Society.

New Guidelines Allow for Individual Risk Consideration

ACP developed the guideline to present the available evidence for screening mammography to physicians and women between the ages of 40 and 49 and to increase their understanding of the benefits and risks of screening mammography in women within this age group.

"We designed our screening mammography guideline based on scientific evidence," says Dr. Lynne Kirk, president of ACP. "It will empower women between the ages of 40 and 49 to become part of the decision-making process and to encourage them to discuss with their physicians the benefits and risks of mammograms."

The guideline states that, according to the evidence studied, breast cancer risk is not evenly distributed in women between the ages of 40 and 49. Thus the benefits of screening mammography are not uniformly applicable in women in this age group. Therefore, women 40 to 49 years of age need to take into account their level of risk and the possible benefits and harms of screening mammography.

"I hope what (the new guidelines) will do is allow women to have the sorts of conversation that discusses for them personally, the risks and benefits of a screening mammogram," says Dr. Kirk.

The discussion should ideally include a family history of breast cancer, whether the woman has had a previous breast biopsy to check for cancer, and other factors, adds Dr. Kirk, a professor of internal medicine at the University of Texas Southwestern Medical Center at Dallas.

"We had not done a specific recommendation on women 40 to 49," she says. "We had recommended for women 50 and over, every year or every other year."

Exam Still Important for Those at Risk

Dr. Kirk says she does not think the new guidelines will discourage women from having the exam. "My guess is, a lot of women will choose to have a mammogram based on this discussion," she says.

Among the risks of mammogram for younger women is the possibility of undue anxiety when a test result is questionable and the patient is sent for a biopsy, and that biopsy produces a false-positive result, Dr. Kirk says. "That risk is certainly much higher in low-risk women 40 to 49," she says.

The ACP committee in charge of drafting the guidelines reviewed 117 studies to evaluate the evidence on the risks and benefits of mammography screening for women in the 40-to-49 age group.

In an editorial accompanying the guidelines, the authors conclude that "no simple recommendation applies to all women in their 40s." The best strategy, they write, is for physicians to listen carefully to patients and to communicate to them "the benefits and limitations of our imperfect tests."

The new guidelines, meant to be used by practicing physicians, are published in the Annals of Internal Medicine, a publication of the ACP.

Circumstances Different for Women in Their 40s

Dr. Cheryl Perkins, senior clinical adviser for Susan G. Komen for the Cure, a Dallas-based organization devoted to fighting breast cancer (formerly known as the Susan G. Komen Breast Cancer Foundation), said setting mammogram guidelines for women in the 40-to-49 age range is difficult.

"It's a very diverse age group," she says. "Some are still child-bearing, some are perimenopausal, some are menopausal."

Dr. Perkins says the new ACP guidelines "won't trigger a change in our recommendations at this point in time. We continue to recommend annual screening for women 40 and over."

"Cancer that occurs in women still in their childbearing years can be more aggressive than cancers in the postmenopausal group," she adds.

Always consult your physician for more information.

Breast Cancer Death Rates Declining

According to a new study published in the Journal of Clinical Oncology, breast cancer death rates in the US have declined, particularly among women with estrogen receptor (ER)-positive tumors and women younger than age 70.

About 75 percent of breast cancer cases are ER-positive - which means their tumors respond to circulating estrogen - and the average age of breast cancer patients at the time of diagnosis is 62.

The study looked at national data on almost 235,000 cases of invasive female breast cancer.

The researchers found that death rates declined by 24 percent between 1990 and 2003; from a peak of 33 deaths per 100,000 women per year to 25 per 100,000 per year.

Among women younger than 70, the death rate declined 38 percent for those with ER-positive tumors, compared with 19 percent for those with ER-negative tumors.

Among women 70 and older, the death rate declined 14 percent for those with ER-positive tumors but did not decline for those with ER-negative tumors.

"These trends in breast cancer mortality since 1990 are likely attributable to at least two important factors: the use of tamoxifen after surgery, which substantially reduces the risk of recurrence in ER-positive tumors only; and widespread use of screening mammography, which is more likely to detect the slow-growing tumors that tend to be ER-positive," says study lead author Dr. Ismail Jatoi, director of the Breast Cancer Center in the Department of Surgery at the National Naval Medical Center.

The study did not investigate why there was less of a decline in breast cancer death rates among older women.

However, the researchers note that previous studies suggested that older women are less likely to receive adjuvant therapy for breast cancer.

Always consult your physician for more information.