This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated.

Contribute Thoughts | Search Serendip for Other Papers | Serendip Home Page

Biology 103
2002 First Paper
On Serendip

Mammograms: A Go or No?

Stephanie Lane

"A mammogram is an x-ray picture of the breast. It can find breast cancer that is too small for you, your doctor, or nurse to feel. Studies show that if you are in your forties or older, having a mammogram every 1 to 2 years could save your life." Though this is currently the official government endorsed idea, the entire controversy over breast cancer preventatives is far much more complex. In what has become perhaps the most highly-debated topic in all of cancer research, the question on the validity of mammograms as a preventative for breast cancer has increasingly caught media attention in the past few years. Media attention notwithstanding, the statistic that suggests that one of every eight women in the U.S. will get breast cancer in their life makes the attention fall closer to home. Whether or not a mammogram can help more than hurt women in preventing cancer is an extremely touchy debate and deserves a considerable amount of research.

Essentially, a mammogram's main idea is to x-ray the breasts in order to find what are called microcalcifications, or tiny build-ups of calcium deposits or tumors that may be unidentifiable from feel. The controversy to the issue lies not in having the mammogram done at all, but the age group that should be included in this. The National Cancer Institute, who is endorsed by the government, released a statement in February of 2002:

"Women in their 40s should be screened every one to two years with mammography. Women aged 50 and older should be screened every one to two years. Women who are at higher than average risk of breast cancer should seek expert medical advice about whether they should begin screening before age 40 and the frequency of screening." (1)

Although many people now take this as a good rule of thumb, there are a number of justifiable reasons that those under 50 should not in fact use mammogram testing. The number of "risks" associated with the testing begins with the fact that the mammogram doesn't always detect breast cancer. The breast density, which just refers to the amount of tissue in the breast that is not fatty, can obscure results. Women under the age of 50 most commonly have a denser breast, which leaves greater room for false-positives or any other abnormal test. For women under 50 who do have cancer, a mammogram detects it in about 70 percent of all cases. For those over 50, about 85 percent of breast cancer cases are detected through mammograms. One source explained the risk as, "If a 40 year old woman is screened every year for 10 years, her chance of having an abnormal mammogram result is about 1 in 3". This chance is decreased for those aged 50-60, to about 1 in 4. And of those that have abnormal results, most do not end up being cancer. (2)

However, this leads into the second aspect of the controversy. When an abnormal result occurs, only a diagnostic test can determine whether or not the "cancer" is legitimate. This often painful, time consuming, worrisome and expensive procedures involve extracting fluids from the breast to be tested in labs. Many women find the wait for further results nerve racking, especially due to the fact that most end up being negative. And, many studies have shown that these women "have more anxiety and worry about having breast cancer, even after being told they do not have cancer."(2) For those under the age of 50, there is about a .03 % chance that the abnormal result will prove to be cancer. For those over 50, that result increases to 14 percent. Still, because younger women have a lower chance of having cancer in the first place, there are a smaller number of breast cancer deaths to prevent, though the percentages may be higher.

Another concern about mammograms revolves around the claim that the radiation exposure to the breast tissue during the process may actually increase the chances of cancer. One source refuted the idea saying that the exposure is comparable to a dental x-ray, with the possibility of causing the death of 1 in 10,000 women, under the condition of one mammogram per year for ten years. (1) In contrast to this finding, other sources claim that the chance is far greater, 1 in 2,700 chance, cumulating with every exposure. (3). The details of this claim and study were not mentioned, however.

And the most obvious affair associated with mammogram testing is their helpfulness in the first place. The idea that the mammogram acts as only a time consuming, expensive insurance that is just as effect with self-breast examinations comes to the forefront. In a 1992 Canadian study of 25,000 women with an equal number of routine screeners and an equal number of non-screeners found that both groups had the same rate of breast cancer deaths. (3) The source also went on to claim that:

"Seven other randomized studies have also reported no statistically significant reduction in the death rates of women who underwent routine screening mammography." (3)

In addition to that finding, the Lancet, a highly esteemed medical journal, published results that clashed with that particular study. In the study of the 54,000 women over a 14 year medical history (half of which were regular screeners while the other half relied on only medical check-ups), a 21% lower death rate from breast cancer was found in the group that used screening. (4) Said Dr. Freda Alexander of the University of Edinburgh in Scotland, who conducted the study, "The results for younger women suggest benefit from introduction of screening before 50 years of age." (4) And, in a comparable study involving 100,000 women, the death rate about 27% percent lower among those who were regular screeners. (4)

Nonetheless, organizations remained strongly divided on the topic. Of those that officially recommend routine mammograms for women under 50 include the American Cancer Society, the American College of Obstetrics and Gynecology, the American College of Radiology and the National Cancer Institute. (2) Of those who do not include, the American College of Physicians, the International Agency for Research on Cancer, the American Academy of Family Practice and the Canadian Task Force on the Periodic Health Exam.

All in all, the data seems to generally support the idea of receiving the routine exams. While nearly every organization approves their use though, mammograms only become controversial when age is factored into the picture. In accordance with the 1999 UK Trial of Early Detection of Breast Cancer, researchers said "The analysis of results by age at entry continues to suggest that screening of women aged 45-49 years is at least as effective as is that for women over 50 years." (4) The principle of defining the controversy by age seems, in retrospect, mildly irrelevant. With the support of data from the numerous valued sources, it is not dangerous nor is it impractical to undergo mammograms for those under 50. But, more importantly, the decision should be made on a personal level. Obviously, for those at greater risk (due to genetics, history, or other factors), the decision seems an obvious one, in accordance with most of studies overviewed here. As with any decision about a person's body, it should strictly remain a personal one but it is always important to make use of responsible medical technologies and resources.


(1)National Cancer Institute

(2)Potential Benefits and Risks of Mammograms

(3)Should you get a mammogram?,

(4)Mammograms before age 50,

| Biology 103 | Course Forum Area | Biology | Serendip Home |

Send us your comments at Serendip

© by Serendip 1994- - Last Modified: Wednesday, 02-May-2018 10:53:19 CDT