While cancer mortality rates have declined across the board, clusters of cancer remain prominent in certain regions and geographies.
The U.S. cancer death rate declined by 20.1% between 1980 and 2014, according to findings published by the American Medical Association. For the study, researchers sought to estimate age-standardized mortality rates by U.S. county from 29 cancers. They came up with these estimates by using deidentified death records from the National Center for Health Statistics and population counts from the U.S. Census Bureau, the NCHS and the Human Mortality Database from 1980 to 2014.
However, for many cancers, high mortality was identified in certain groups of counties, according to the first-ever county-by-county analysis of cancer deaths across the nation.
Between 1980 and 2014, the U.S. cancer death rate declined from 240.2 cancer deaths per 100,000 Americans to 192, according to the study. Researchers said 19.5 million cancer deaths were recorded in the U.S during that time, with the three highest rates including 5.7 million due to tracheal, bronchus and lung cancer; 2.5 million due to colon and rectum cancer; and 1.6 million due to breast cancer.
However, large differences were seen in the mortality rate among counties, researchers said. For instance, in 1980, cancer mortality ranged from 130.6 cancer deaths per 100,000 Americans in Summit County, Colo., to 386.9 in North Slope Borough, Alaska. In 2014, mortality rates ranged from 70.7 in Summit County, Colo., to 503.1 in Union County, Fla., per the study.
Researchers said for many cancers, there were groups of counties with especially high mortality rates. They said these counties were in a wide range of U.S. locations and in different regions. They said clusters of breast cancer were found in the south 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.
“Cancer mortality declined overall in the U.S. between 1980 and 2014. Over this same period, there were important changes in trends, patterns and differences in cancer mortality among U.S. counties. These patterns may inform further research into improving prevention and treatment,” researchers concluded.
You can access the whole study via the Journal of the American Medical Association (JAMA).