Can Mapping Differences in Cancer Rates Help Pinpoint Environmental Factors?
“A map showing stark differences in the incidence of 10 types of cancer between Spain and Portugal has sparked a race to pinpoint causes and risk factors people should avoid.”
It shows huge differences for people living only a short distance apart, sometimes across the border between Spain and Portugal, and others occurring within the same country. Scientists say it will take years to solve the puzzle completely but are confident that the map provides the pieces. There are easier questions and more complex riddles. But it all points to environmental factors — as opposed to genetics — playing a major role in causing cancers.
The lung cancer map tells a clear story of far higher levels of smoking tobacco in Spain than in Portugal, with the latter country showing a consistent hue of dark blue for a lower risk of mortality, while Spain has large areas lit up in red, at least on the map representing men. Twenty per cent of Spanish adults are daily smokers, compared with just over 11 per cent in Portugal. But the data from cancer of the larynx, also linked to smoking, tells a vastly different story, with a high mortality risk for men shown straddling the border in southern Portugal and south western Spain, as well as patches in the north of both countries. “The lung cancer and smoking connection is very clear, so why in other cancers that have a strong link with tobacco are we seeing such surprising differences?” asks Pablo Fernández-Navarro, the lead co-ordinator of the atlas from the Spanish side.
“This is what is so fantastic. If whole countries had uniform levels of mortality, the maps would be in plain colours. Given that it is not the case, now we have to investigate and explain these differences, eliminating one factor after another,” Fernández-Navarro told The Telegraph.
In the case of larynx cancer, the Spanish epidemiologist says the map confirms that smoking is by no means the only risk factor, and that other elements must also be at work, from alcohol intake to levels of pollutants such as asbestos or petrochemicals in the environment.
Thanks to Slashdot reader Bruce66423 for sharing the link.
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