Cancer Incidence In Different Parts Of The USA

Different forms of cancer seem more prevalent in some areas of the USA compared to others.  For example, read here. Part of abstract:

For many cancers, there were distinct clusters of counties with especially high mortality. The location of these clusters varied by type of cancer and were spread in different regions of the United States. Clusters of breast cancer were present in the southern belt and along the Mississippi River, while liver cancer was high along the Texas-Mexico border, and clusters of kidney cancer were observed in North and South Dakota and counties in West Virginia, Ohio, Indiana, Louisiana, Oklahoma, Texas, Alaska, and Illinois.
CONCLUSIONS AND RELEVANCE:
Cancer mortality declined overall in the United States between 1980 and 2014. Over this same period, there were important changes in trends, patterns, and differences in cancer mortality among US counties. These patterns may inform further research into improving prevention and treatment.

This differences can be due to genetic differences between demographic groups variably distributed in these regions, differences in lifestyle including diet and physical activity, different distribution of age groups in these regions, socioeconomic status and access to health care, etc.  As the authors state, hopefully this information can be useful in optimizing prevention and treatment.