Breast Density Linked To City Life

This blog entry is about a news study that found “Women who live or work in urban areas are more likely to have dense breasts than those who live in the suburbs, a finding that may suggest increased risk for breast cancer.”

The findings of the study are related to Happeh Theory concepts about Breast Cancer. A discussion of those concepts is presented in the following video.

Happeh Theory and Breast Cancer

The news story reports that doctors are linking their findings about breast density to geographic location. That is wrong according to Happeh Theory. According to Happeh Theory it is the lifestyle of the women, a hard working stressful life, that is making their breasts dense.

The original news story is  reprinted below.


Women who live or work in urban areas are more likely to have dense breasts than those who live in the suburbs, a finding that may suggest increased risk for breast cancer.

Women ages 45 to 54 who lived in central London were about 2.22 times more likely (95% CI: 1.05 to 4.68) to have very dense breasts than women who lived outside the city and, conversely, were less likely to have low breast density — 21% versus 26% for non-city dwellers, Nicholas M. Perry, M.B.B.S., of the London Breast Institute, told attendees at the Radiological Society of North America meeting here.
Action Points

* Explain to interested patients that this finding is from an observational study and so should be considered hypothesis-generating only.

* Explain to interested patients that other studies have identified breast density as a risk factor for breast cancer, but the mechanism is unclear.

* Note that this study was published as an abstract and presented at a conference. The data and conclusions should be considered to be preliminary until published in a peer-reviewed publication.

“The difference between 21% and 26% may not seem like much, but it is more than a 25% increase based on the denominator figure,” Dr. Perry said.

Furthermore, 24% of women whose zip codes correlated with addresses in central London had extremely dense breasts (more than 75% fibrotic tissue) versus 19% of women living outside the city, he said.

Although the data were based on women living in London and its surrounding communities, Dr. Perry said he is “not persuaded that London is any different from any other urban population — urban is urban.”

The link between city life and breast density emerged from analysis by Dr. Perry and colleagues of digital mammograms of 972 women, including 318 women who lived in the heart of London.

He cautioned, however, against over interpretation of the findings. “We are not reporting why this occurs, but rather whether there was a relationship between residence and breast density,” he said. “And we are not saying that more urban women are dying from breast cancer; breast cancer mortality is decreasing among all women in all regions.”

And because the data are based on a single-mammography “snapshot of the population,” he had no data about the number of women who developed breast cancer. Nailing down the incidence of breast cancer among women with dense breasts would “take about 10 years,” Dr. Perry said.

Likewise, he said he could only speculate about the possible explanation for the difference in breast density based on zip code.

“There have been some studies that suggest exposure to fossil fuels is associated with increased breast density,” he said. Moreover, several factors — age, use of hormone replacement therapy, early menarche, delay in childbirth, and body mass index are all associated with increased breast density.

“It is possible that women who live in urban areas are more likely to delay childbirth, use HRT, and may be both younger and slimmer than non-urban women,” he said.

The researchers correlated digital mammograms to zip codes of women.

He then used zip codes to identify women’s workplaces and he discovered that “women who commuted into London also were more likely to have dense breasts. So it was clearly something about exposure to the urban environment.”

The observation has at least two implications for clinical practice, Dr. Perry said. “First, urban women are less likely to participate in screening, yet these data suggest they have increased risk because of breast density,” he said. “So, these data suggest the need to increase educational efforts in this population in order to increase participation in screening programs.”

But traditional mammography may not pick up lesions in dense breasts, he said. “Digital mammography is more effective for women with dense breasts and I think these data support the need for more digital mammography,” he said.

Dr. Perry said only about 10% of mammography centers in England offer digital mammography. In the U.S. it is available in only about 25% of centers.

Philip O. Alderson, M.D., of Columbia University, said that data from DMIST-I, a 50,000-patient trial that compared digital mammography to film mammography “found overall no difference, but Dr. Perry is correct that among the subset of women with dense breasts digital mammography appears to be superior.”

Dr. Alderson, who was not involved in the study but chaired the RSNA press conference, said he was not aware of U.S. studies linking urban lifestyle to dense breasts, nor was he aware of anecdotal reports about increased breast density among women in New York. But, he said, “I practice in an urban setting and our patients are urban patients so it would be difficult to make those types of comparisons.”

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