The closest thing I could find to data on the radon issue is this:
http://health.ri.gov/publications/re...ommunities.pdf
It shows radon levels higher in south county but incidences of lung cancer "lower in non metro areas" in RI, so I'm assuming it means south county.
Every study I've ever seen correlates smoking as no. 1 with lung cancer at high levels. There is also controversy over whether there actually is a radon/lung cancer correlation. If there is, I would hazard a guess that people who have basements (common in the NE versus some other parts of the country) might have more of an incidence.
But even figuring that out would be far from simple. There are so many factors that go into all cancer diagnoses: age, ethnic group, water, air, general health habits, genetics, viruses, etc. that direct correlations concerning one factor can be very hard to prove.