A new study by UK researchers suggests that women who live in cities and urban areas are at greater risk from breast cancer because they tend to have denser breasts.
The study is the work of Dr Nicholas M. Perry, director of The London Breast Institute at The Princess Grace Hospital in London, and colleagues, and was presented yesterday, Monday 26th November, at the annual meeting of the Radiological Society of North America (RSNA), which is being held in Chicago this week.
Perry urged women who lived in cities to have more frequent screening for breast cancer, since they are at higher risk, but the irony is that women in London tend to visit screening clinics less often that their rural counterparts.
Breast tissue is made of a mixture of fatty tissue and glandular tissue. Women with a higher proportion of glandular tissue have denser breasts and nearly four times the risk of getting breast cancer compared to women whose breasts have more of the fatty tissue.
Perry and his team looked at digital mammograms of 972 women who lived in urban, suburban and rural areas in and around London, and found there was a link between where women lived and the density of their breast tissue.
The results showed that women who lived in London had significantly denser breast tissue compared to those who lived outside the city.
The chances of having increased density of breast tissue was doubled in the age range 45 to 54 years old, but further analysis showed the overall differences by area were greater in women under 50.
The researchers said that more research was needed to pinpoint the underlying cause of the geographical differences in breast tissue density in women. It could for instance be lifestyle, stress, or work related, or even other factors such as pollution.
However, whatever the reason, Perry urged all women, regardless of where they lived and worked, to stick to their recommended breast screening programme. He also recommended digital mammography be used to screen women with denser breasts since it is easier to see cancer in dense breast tissue with this technology than the more conventional film screen.
Perry said:
“Regular breast screening with mammography saves lives,” adding that:
“Access to breast screening for women living in cities must be prioritized.”
Another study that was presented to the RSNA in Chicago yesterday looked at the effect of the Western way of life on breast composition. Led by Dr Miriam Sklair-Levy of the Hadassah Medical Center in Jerusalem, researchers compared the breast tissue composition of Israeli women and of Ethiopian women who had immigrated to Israel.
They found that the women who had been born and raised in Ethiopia and then moved to Israel had significantly lower breast density than women born and raised in Israel. And they found that Ethiopian women who had begun to lead a Western way of life, such as having fewer children, increased use of hormones, and changed their diets, had significantly higher breast density than women who had only recently come to Israel from Ethiopia.
Written by: Catharine Paddock