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An announcement by a scientific board at the National Cancer Institute (NCI) in January
2002 has raised questions about the benefits of mammography
in helping to prevent breast cancer deaths. Cancer organizations have encouraged women in
their forties to begin receiving screening mammograms based on studies from the 1970s and
1980s that showed that mammography could save women’s lives by detecting the cancer
early. However, the scientific panel argued that those studies were flawed. Yet, in
statement issued on February 21, U.S. government health officials said there is sufficient
evidence that receiving mammograms every one to two years is effective for women in their
forties.
Mammography is a special type of x-ray imaging that uses low dose x-rays with high
contrast to create detailed images of the breast. Mammography is currently the only exam
approved by the U.S. Food and Drug Administration (FDA) to screen for breast cancer in
women who do not show any signs or symptoms of the disease, such as a breast lump. For the
last several years, the National Cancer Institute has recommended that all women 40 years
of age and older begin receiving annual screening mammograms every one to two years, and
then every year beginning at age 50. Other cancer groups recommend that women begin yearly
screening mammograms at age 40.
The argument for mammography is based on the following logic: mammography helps detect
breast cancer in very early stages. The earlier that breast cancer is detected, the more
likely it can be successful treated and the patient will survive. Therefore, routine
screening mammograms save lives. This logic is based on past studies from the 1970s and
1980s, which have shown that routine mammograms can reduce breast cancer deaths by 30%.
However, an independent scientific panel (called the PDQ, Physician Data Query), which
advises the National Cancer Institute, recently announced that the past studies that
showed mammography prevents deaths were flawed. Instead the panel argued that there is
insufficient evidence to say whether mammography really saves women’s lives.
The panel, which is made up of physicians and cancer experts, admitted that their
findings will cause confusion for the over 30 million American women who have annual
screening mammograms. Furthermore, the panel’s announcement contradicted the
NCI’s current mammography recommendations and the information on its website that
says that mammography prevents deaths from breast cancer.
Dr. Peter Greenwald, Director of Cancer Screening at the National Cancer Institute,
believes that early detection plays an important role in controlling cancer, which is why
the NCI recommends beginning screening mammography at age 40. Dr. Greenwald says that the
debate over mammography has nothing to do with its ability to detect breast cancer.
Mammography has been proven to find cancer in its very earliest stages. However, the
debate lies in whether treating these very small cancers actually prevents deaths from
breast cancer or merely results in the overtreatment of tumors that may not ever progress
into life-threatening cancers.
On February 21, 2002 Health and Human Services Secretary Tommy Thompson announced that
the NCI is not changing its recommendations on mammography. The decision comes after the
U.S. Preventive Services Task Force reviewed eight studies of mammography. The task force
concluded that mammography can reduce breast cancer deaths by 20% in a 10 year period.
According to the American Cancer Society (ACS), while the number of breast cancer cases
continues to rise, breast cancer deaths have decreased significantly over the last 10
years. The ACS attributes this decline in deaths to improved screening and treatment for
breast cancer.
In addition to mammography, the NCI and ACS also recommend regular physician-performed clinical breast exams and monthly breast self-exams to help detect breast cancer.
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