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Geographically-based breast cancer screening in Geneva

© 2018 EPFL

© 2018 EPFL

In Geneva, 85% of women are regularly screened for breast cancer. But a study conducted by the GIRAPH Lab - a research unit materializing the pooling of complementary skills between the Unit of Population Epidemiology (UEP) of the Geneva University Hospitals (HUG) and the Laboratory of Geographic Information Systems (LASIG) at EPFL - reveals that entire neighborhoods escape cancer screening programmes.

Conducted among 5,000 Geneva female residents aged 50 to 74 years old, this study makes it possible for the first time to draw up a prevention map where islands of non-adherence to breast cancer screening can be observed. Idris Guessous, head of the service de médecine de premier recours (SMPR) at the HUG, and one of the authors of the study explains: "We can clearly identify neighborhoods in Geneva where women participate collectively, and other areas where women do not participate and this probably for years" . Among the latter neighborhoods, Guessous marks off Lake Geneva right bank, downtown, Meyrin, Onex, La Jonction, "territories known to show economic deprivation and a lower education level than what is observed on the left bank", he explains.

Mimetism effect

If socio-economic status is key, it does not constitute the only factor. The study also reveals a mimicry effect between women: they would influence one another according to their geographical proximity. "One can imagine that in shared neighborhoods women have discussions about these thematics," Idris Guessous says. "'Have you been invited to participate in cancer screening programme, what do you think?" Women of opposite opinions could exchange their views, between neighbors. One can imagine that this type of information exchange or of point of view expression influences women from the same neighborhood."

A tool for precision medicine

Such a "cancer screening programme participation map" questions prevention institutions and offers a very precise tool for better targeting awareness campaigns related to breast cancer screening. Béatrice Arzel, director of the Geneva Foundation for Breast Cancer Screening says: "This map comes to tell us: 'there are actions that we did not implement in given neighborhoods, and we must reach them'. "We must try to understand the reasons why these women do not participate and communicate more and better in the activity networks of these neighborhoods." In Geneva, an average of 450 breast cancers are diagnosed each year, and nearly 80 women die. In Switzerland, more than 5,700 breast cancers are diagnosed each year, and nearly 1,400 women die.


The results of this research constitute a perfect illustration of the many advantages that can be obtained from such a close collaboration between medicine and environmental engineering. This is exactly with the aim of precisely guiding prevention actions in population health that Dr Idris Guessous (UEP, HUG) and Dr Stéphane Joost (LASIG, EPFL) created the GIRAPH Lab a few years ago, a research unit whose expertise consists in analysing the geographical distribution of diseases and its relationship with characteristics of the urban environment. Last June, they demonstrated by means of a similar method the influence of night-time road and rail traffic noise on sleep disorders in collaboration with Dr. Heinzer and Dr. Haba-Rubio of the Centre d'Investigation et de Recherche sur le Sommeil (CIRS) au CHUV.

Adapted and translated from RTS Info - Flore Amos / kkub


The Bus Santé study is funded by the General Directorate of Health, Canton of Geneva, and the Geneva University Hospitals (HUG).


Sandoval, J. L., Himsl, R., Theler, J.-M., Gaspoz, J.-M., Joost, S., & Guessous, I. (2018). Spatial distribution of mammography adherence in a Swiss urban population and its association with socioeconomic status. BioRxiv, 404673. doi:10.1101/404673 - Cancer Medicine, in Press

Joost, S., Haba-Rubio, J., Himsl, R., Vollenweider, P., Preisig, M., Waeber, G., … Guessous, I. (2018). Spatial clusters of daytime sleepiness and association with nighttime noise levels in a Swiss general population (GeoHypnoLaus). International Journal of Hygiene and Environmental Health, 221(6), 951–957. doi:10.1016/j.ijheh.2018.05.004