Does where you live factor into cancer mortality?

More than 19.5 million cancer deaths were recorded in the United States from 1980 to 2014. When digging deeper, the Institute for Health Metrics and Evaluation at the University of Washington found that cancer deaths were “clustered,” with many U.S. counties above the national average.

Of note, there were statistically significant increases in cancer mortality between 1980 and 2014 in 160 counties, with the highest rates of increase observed in Kentucky and scattered across regions of the South.

“Such significant disparities among US counties is unacceptable,” said Dr. Ali Mokdad, lead author on the study and Professor of Global Health at the IHME. “Every person should have access to early screenings for cancer, as well as adequate treatment.”

The study was able to identify clusters of high rates of change among U.S. counties, which is important for providing data to inform the debate on prevention, access to care, and appropriate treatment. Monitoring cancer mortality at the county level can help identify worsening incidence, inadequate access to quality treatment, or potentially other etiological factors involved. [1]

For example, between 1980 and 2014:

• Liver cancer mortality increased in nearly every county. Clusters of counties with large increases were found in California, Oregon, Washington, New Mexico, and Texas. While alcohol is a well-known risk factor for liver cancer, the counties with high or increasing death rates differ from those known for high rates of alcohol consumption.
• Fewer Americans smoke today than in previous decades, but parts of the South and many rural areas still show high rates of this deadly habit. It is not surprising that these same areas show high rates of lung cancer, especially within states like Kentucky, Tennessee, Alabama, Missouri, Arkansas, Mississippi, and rural Alaska. More aggressive efforts to discourage smoking in these areas are crucial to help address this problem.
• The majority of counties witnessed decreases in breast cancer death rates since 1980; however, there are clusters of high mortality rates in counties along the Mississippi River. The lowest rates appear in parts of the West, Midwest, and Northeast.
• There are high death rates from prostate cancer in groups of counties in Alabama, Mississippi, Georgia, South Carolina, and Virginia.
• Counties with the highest death rates from kidney cancer also were identified along the Mississippi River, as well as in Oklahoma and Texas. In addition, certain areas in Alaska and the Dakotas with large Native American populations showed rates higher than the national average.

“For cancers with high survival rates, such as testicular cancer and Hodgkin lymphoma, wide differences in mortality rates in the US should raise a red flag,” said Dr. Christina Fitzmaurice, Assistant Professor at IHME and the Division of Hematology at the University of Washington. “Clusters of counties with increasing death rates from these cancers need to be examined and questions raised regarding access to primary care for early detection and specialized cancer treatment services.”

Researchers point to smoking, obesity, and diet as key factors in cancer mortality.

For some cancers, mortality rates declined in nearly all counties (colon and rectum, larynx, lip and oral cavity, nasopharynx, other pharynx, stomach, gallbladder and biliary tract, breast, cervical, prostate, testicular, Hodgkin lymphoma) or increased in nearly all counties (liver, mesothelioma); for the remaining cancers, rates increased in some counties and declined in others.

In 2014, there were clusters of high mortality in several areas of the South, in Kentucky, West Virginia, Alabama, and along the Mississippi River, and in Western Alaska. There also were high rates in counties in North and South Dakota and Texas, while lower rates were present in Utah and Colorado.

“As the U.S. enters a new debate about access to health care, these findings on the wide differences in cancer mortality should inform the discussion,” said researcher Laura Dwyer-Lindgren, a co-author of the study. “What's causing cancer to be so much more fatal in one part of the country than in other parts demands further investigation.”

• Trends and Patterns of Disparities in Cancer Mortality Among US Counties, 1980-2014
• Counties with the lowest and highest age-standardized mortality rate in 2014, by cause of death