Cancer death rates vary nearly two-fold when mapped by U.S. congressional district, with rates generally lowest in Mountain states and highest in Appalachia and areas of the South, according to a new analysis by American Cancer Society researchers.

A lot of attention has been paid to genetics in breast cancer as disease rates rise, but most women have no family history of the disease, suggesting that there is an environmental risk we don’t yet understand, says environmental health scientist Laura Vandenberg in the School of Public Health and Health Sciences at the University of Massachusetts Amherst.

Many adults in the U.S. are not getting the recommended screening tests for colorectal, breast and cervical cancers, according to data published in the Centers for Disease Control and Prevention’s (CDC) Morbidity and Mortality Weekly Report. For 2013, screening for these types of cancers either fell behind previous rates or showed no improvement.