Support for ‘Minority Report’ on Mammography for Women in Their 40s

Weighing in unambiguously on the controversy over the National Institutes of Health (NIH) consensus statement on breast cancer screening for women 40 to 49 years old, David H. Moore, MD, stated: “I believe very strongly in the ‘minority report’ position that a 17% reduction in breast cancer mortality in younger women should not be considered trivial.” The NIH panel had found that current data do not warrant a universal recommendation for mammography in women in their 40s. Dr. Moore is associate professor of obstetric/gynecology and chief of gynecologic oncology at Indiana University School of Medicine, Indianapolis.

Speaking at the 1999 American College of Obstetricians and Gynecologists (ACOG) meeting, Dr. Moore noted that although the vast majority of breast (and ovarian) cancers are sporadic and cannot be explained or predicted based on known genetic mutations, the onset of familial breast cancer is earlier. Such cases are detected, on average, when women are in their late 40s—10 to 15 years earlier than in the general population. “That is significant when you sit down and start thinking about screening programs,” Dr. Moore observed.

Possibility of Earlier Detection Outweighs Drawbacks of Screening

Dr. Moore acknowledged the down- side of mammography, including the 8% to 12% false-positive rate and the fact that 25% of all breast cancers are missed by mammograms. Noting a study documenting a 24% 4-year false-positive rate for mammograms and a 13.4% rate for clinical breast examinations, Dr. Moore concluded that the additional procedures and anxiety resulting from screening are justified by the potential benefits of earlier detection—reductions in mortality and morbidity with a decreased need for radical mastectomy. Radiation exposure from mammography, he commented, is very low.

A further reason to encourage mammography among younger women, Dr. Moore said, is that the incidence of breast cancer doubles between the age ranges of 40 to 44 and 45 to 49 years. “Mammography finds earlier and slower-growing cancers with generally better prognoses,” Dr. Moore added, emphasizing again that early detection provides greater opportunity for less extreme therapies.

Optimal Frequency of Screening Unknown

The optimal frequency of mammographic screening for women in their 40s has not been determined. In his own practice, Dr. Moore related, “I offer mammograms on an every-other-year basis to all women in their 40s, and for those with a strong family history of breast or ovarian cancer I suggest annual exams.”

Dr. Moore emphasized that a negative mammogram in the presence of a suspicious lesion on clinical breast examination does not eliminate the need for biopsy or at least fine-needle aspiration. After such a finding, the incidence of positive nodes increases threefold among women who wait many months for their biopsy.

 “To say mammography is not indicated for women in their 40s is not in the best interest in women’s health care,” he concluded.