There are many geographic factors, which seem to play critical role in carcinogenesis. One represantive example is the radonium levels by means of annual rates, which seem to be related to soil composition and altitude. Also eating habits, culture, way of life, childbearing age are relevant to some diseases and many many more. geomedicine is a very interesting field of medicine that deals with geographic factors in disease and uses statistical data, such as prevalence, approaching a little through the field of clinical epidemiology and biostatistics. :)