"People often think more is better at healthcare, and sometimes more is not better," says Dr. Anthony Billittier of D'Youville College, a former Erie County Health Commissioner. He says his concern is a false positive. "Women who had a mammogram before age 50 and found something on it that turned out to be nothing. But it turned out into a number of tests that turned out to be nothing, and sometimes the results are bad."
Billittier says both sides of the coin need to be looked at, and that's what he thinks is behind the recommendation to lower the starting age for mammograms from 50 to 40.
From The National Cancer Institute, NIH
What are NCI´s recommendations for screening mammograms?
Women age 40 and older should have mammograms every 1 to 2 years.
Women who are at higher than average risk of breast cancer (for example, because of a family history of the disease or because they carry a known mutation in either the BRCA1 or the BRCA2 gene) should talk with their health care providers about whether to have mammograms before age 40 and how often to have them.
Finding cancer early does not always reduce a woman’s chance of dying from breast cancer.
Even though mammograms can detect malignant tumors that cannot be felt, treating a small tumor does not always mean that the woman will not die from the cancer. A fast-growing or aggressive cancer may have already spread to other parts of the body before it is detected. Women with such tumors live a longer period of time knowing that they likely have a fatal disease.
In addition, screening mammograms may not help prolong the life of a woman who is suffering from other, more life-threatening health conditions.
False-negative results occur when mammograms appear normal even though breast cancer is present. Overall, screening mammograms miss about 20 percent of breast cancers that are present at the time of screening.
The main cause of false-negative results is high breast density. Breasts contain both dense tissue (i.e., glandular tissue and connective tissue, together known as fibroglandular tissue) and fatty tissue. Fatty tissue appears dark on a mammogram, whereas fibroglandular tissue appears as white areas. Because fibroglandular tissue and tumors have similar density, tumors can be harder to detect in women with denser breasts.
False-negative results occur more often among younger women than among older women because younger women are more likely to have dense breasts. As a woman ages, her breasts usually become more fatty, and false-negative results become less likely. False-negative results can lead to delays in treatment and a false sense of security for affected women.
False-positive results occur when radiologists decide mammograms are abnormal but no cancer is actually present. All abnormal mammograms should be followed up with additional testing (diagnostic mammograms, ultrasound, and/or biopsy) to determine whether cancer is present.
False-positive results are more common for younger women, women who have had previous breast biopsies, women with a family history of breast cancer, and women who are taking estrogen (for example, menopausal hormone therapy).
False-positive mammogram results can lead to anxiety and other forms of psychological distress in affected women. The additional testing required to rule out cancer can also be costly and time consuming and can cause physical discomfort.
Overdiagnosis and overtreatment.
Screening mammograms can find cancers and cases of ductal carcinoma in situ (DCIS, a noninvasive tumor in which abnormal cells that may become cancerous build up in the lining of breast ducts) that need to be treated. However, they can also find cancers and cases of DCIS that will never cause symptoms or threaten a woman’s life, leading to “overdiagnosis” of breast cancer. Treatment of these latter cancers and cases of DCIS is not needed and leads to “overtreatment.” Overtreatment exposes women unnecessarily to the adverse effects associated with cancer therapy.
Because doctors often cannot distinguish cancers and cases of DCIS that need to be treated from those that do not, they are all treated.
Mammograms require very small doses of radiation. The risk of harm from this radiation exposure is extremely low, but repeated x-rays have the potential to cause cancer. The benefits of mammography, however, nearly always outweigh the potential harm from the radiation exposure. Nevertheless, women should talk with their health care providers about the need for each x-ray. In addition, they should always let their health care provider and the x-ray technician know if there is any possibility that they are pregnant, because radiation can harm a growing fetus.