Breast cancer is one of the main causes of mortality and loss of quality of life in the female population worldwide. This type of cancer is more common in women who are in the postmenopausal stage, probably because they have been exposed to endogenous estrogens for a longer time, or due to other factors such as being overweight or obese, or due to a lack of physical activity, while In premenopausal women, the appearance of this disease has been related to a more aggressive biology and the presence of certain genes.
A new study has shown that environmental pollution also influences a woman’s chances of developing breast cancer after menopause, revealing that the risk is higher for women who live in more polluted areas, and lower for those who reside for a long time. time in places with a good proportion of green areas. The results have been published in Environmental Research.
The work was carried out by a group of researchers from the Jordi Gol Institute for Primary Care Research (IDIAPJGol) in Barcelona, who followed up 1,054,180 premenopausal women and 744,658 postmenopausal women for an average of 10 years, between 2009 and 2018, with the aim of analyzing the association between air pollution, green spaces and the risk of developing breast cancer both before and after menopause. The analysis included data from 1,798,838 women between 17 and 85 years of age, prospectively collected from the Information System for Research in Primary Care (SIDIAP) in Catalonia.
Reduce air pollution and increase green spaces
At the level of environmental pollution, measurements of polluting particles (PM2.5 and PM10) and nitrogen dioxide (NO2) were made. To calculate the amount of green spaces available, the NVDI (Normalized Difference Vegetation Index) and the percentage of green spaces in the census tracts where the study participants resided were used.
An increase in the concentration of PM2.5, PM10 and NO2 increases the risk of breast cancer in postmenopausal women, but in premenopausal women only extremely high concentrations of PM10 were associated with an increased risk
Throughout follow-up, 6,126 (0.6%) premenopausal women received a diagnosis of breast cancer, as did 17,858 (2.4%) in the postmenopausal cohort. The median follow-up time was five years for women who developed breast cancer and 10 years for those who did not. For premenopausal women, the mean age at the start of the study was 38 years for those diagnosed with breast cancer and 32 years for those who were not. On the other hand, in postmenopausal women the mean age was 62 and 63 years, respectively.
The researchers found that an increase in the concentration of PM2.5, PM10 and NO2 increases the risk of breast cancer in postmenopausal women, while in premenopausal women only extremely high concentrations of PM10 (≥46 μg/m3) were observed. were associated with an increased risk of developing this tumor.
NDVI was only associated with a reduced risk of cancer among postmenopausal women who did not move during follow-up, or who were followed for at least three years. The researchers have stated that “policies to reduce air pollution and increase the availability of green spaces could help reduce the risk of breast cancer.” And they add that “more studies are needed to better understand the details of the potential effect of green spaces on the risk of breast cancer.”
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