Urban Women May Have Greater Breast Cancer Risk

Urban Women May Have Greater Breast Cancer Risk
MONDAY, Nov. 26 (HealthDay News) -- Women who live in urban areasappear to have more dense breast tissue than their suburban or ruralcounterparts, new research suggests.
The finding is potentially important because women with more densebreasts have a higher risk of breast cancer.
The study, which compared women living and working in London to thoseliving outside the city, found that city-dwelling women were more likelythan their rural peers to have dense breasts.
"Our study suggests that the closer to urban and high populationdensities that a woman resides, and in particular works, the greaterlikelihood there is that she will have denser breasts," said study authorDr. Nicholas Perry, director of the London Breast Institute at thePrincess Grace Hospital.
"For every 1 percent increase in breast density, there is said to be a2 percent increase in the relative risk of developing breast cancer," headded.
Perry was to present the findings Monday at the Radiological Society ofNorth America's annual meeting, in Chicago.
Each year, nearly 180,000 American women are diagnosed with invasivebreast cancer, and about 40,500 die from the disease, according to theAmerican Cancer Society (ACS). Over a lifetime, about one in eight womenwill develop breast cancer.
Known risk factors include a family history of the disease, gettingyour first period before the age of 12, beginning menopause after age 55,not having children or having your first child after 30, being overweight,drinking more than one alcoholic drink a day, and living a sedentarylifestyle, according to the ACS.
The new study included digital mammograms from 972 women, between 29and 87 years old, living or working in rural, suburban and urban areas.Two hundred and twenty-five women were from rural areas, 135 lived in thesuburbs, and 257 women either lived or worked in an urban area.
Breast density isn't an indicator of breast size, noted Dr. JuliaSmith, director of the New York University Cancer Institute's BreastCancer Screening and Prevention Program. Instead, breast density indicatesmore glandular breast tissue and ducts rather than fatty tissue. Thatmeans more area for breast cancer to develop and hide, she explained.
Overall, 26 percent of the women in the study had breasts that wereclassified as fatty, while the remaining women had density findingsranging from scattered to extremely dense. Thirty-one percent of the ruralresidents had breasts classified as fatty, while 26 percent of suburbanwomen and just 22 percent of urban women did.
Perry and his colleagues found that women who lived and worked in acity were more likely to have dense breasts than either their rural orsuburban counterparts. Urban women had a 54 percent greater chance ofhaving dense breasts than women living in rural areas, and suburban womenhad a 14 percent higher risk of dense breasts than rural women.
"This is an interesting finding," Smith said. "But, we need to teaseout the confounding factors. Are these population issues or does being inan urban environment increase risk?"
For example, she said, urban women may have better diets and mayexercise more, both of which can contribute to denser breast tissue, Smithsaid.
Perry also said there are many lifestyle factors that need to beconsidered, and he hopes that now that he and his colleagues have drawnattention to the issue, more studies will be done to uncover the cause ofthis disparity.
One concern that Perry has is that past studies have found that urbanwomen may be less likely to undergo screening for breast cancer, and thisstudy suggests that it may be even more important for these womento get mammograms as recommended.
"All women should be given the opportunity to participate in breastscreening programs, if eligible, but perhaps women in the city need to beextra vigilant in this regard and not miss out," Perry said.
More information
To learn more about breast cancer prevention, visit BreastCancer.org.