The incidence of cancer is lower among people living in rural areas in the United States than among those living in more metropolitan areas. But cancer death rates are the opposite ― death rates are highest in rural America, according to the first comprehensive report of its kind from the Centers for Disease Control and Prevention (CDC).
For all cancers combined, the average yearly incidence rate was 442 cases per 100,000 persons in rural counties. This was lower than rates in nonmetropolitan urban counties (455 cases), metro counties with fewer than 1 million residents (456 cases), and metro counties with 1 million or more residents (457 cases).
The death rates told another story.
For all cancers, the average yearly mortality rate was 180 deaths per 100,000 persons in rural counties. This death rate was higher than those in nonmetropolitan urban counties (177 deaths), metro counties with less than 1 million residents (166 deaths), and metro counties with 1 million or more residents (158 deaths).
All incidence and death rates were age-adjusted.
“Geography alone can’t predict your risk of cancer, [but] it can impact prevention, diagnosis, and treatment opportunities — and that’s a significant public health problem in the US,” CDC Acting Director Anne Schuchat, MD, said in a statement.
“Many cancer cases and deaths are preventable, and with targeted public health efforts and interventions, we can close the growing cancer gap between rural and urban Americans,” she added.
The report was published online July 6 in the Morbidity and Mortality Weekly Report.
The authors used cancer incidence data from the CDC’s National Program of Cancer Registries along with data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program to examine geographic differences in cancer incidence. To arrive at mortality rates, they analyzed data from the National Vital Statistics System.
“The most recent data available are through 2013 for incidence and through 2015 for deaths,” observe the authors.
The report documents average annual age-adjusted incidence rates for the period 2009 to 2013 and for cancer death for the period 2011 to 2015.
The analysis showed that for many cancers, differences in incidence rates between rural and urban counties were not always significant, but they were often significant for potentially preventable cancers.
For example, incidence rates for breast cancer and late-stage breast cancer as well as prostate cancer were lower in rural counties than in metropolitan areas, but rates in rural areas were higher when it came to lung cancer, late-stage lung cancer, colorectal cancer, and late-stage colorectal cancer as well as cervical cancer.
Incidence rates for cancer of the stomach, liver, uterus, bladder, and thyroid were also lower among those living in rural areas of the country than for any other geographic region.
Death Rate Dropping
The authors point out that the yearly age-adjusted death rate for all cancer sites combined dropped in both rural and urban regions by approximately 1% per year from 2004 to 2013, but the death rate decreased at a slower pace in rural areas, at a reduction of 1% a year from 2006 to 2015, compared to 1.6% per year in urban areas, thereby increasing the difference in cancer-related mortality rates between rural and urban regions.
“Nonmetropolitan rural counties had higher incidence and death rates for cancers related to smoking (eg, lung and laryngeal cancers) and cancers that can be prevented by screening (ie, colorectal and cervical cancers),” the authors add.
In rural counties, incidence rates of human papillomavirus (HPV)–related cancers, including cervical and oropharyngeal cancer, were also higher, whereas incidence rates were lower for cancers related to other infectious agents, such as liver cancer.
Indeed, an analysis of cancer risk with respect to the presence of known risk factors found that the prevalence of smoking was highest among people living in rural areas, as was the prevalence of being overweight or obese and of not getting enough physical activity. Each of these factors is associated with increased cancer risk, the authors point out.
The authors indicate that that proven strategies for reducing the disparities in cancer incidence and death rates between rural and urban areas include the following:
- Promotion of healthy behaviors to reduce cancer risk: This would include smoking prevention, cessation among smokers, and the elimination of secondhand smoke. Limiting excessive exposure to ultraviolet light from the sun, as well as the use of tanning beds, making healthier food choices, and engaging in more physical activity can help prevent or reduce obesity and with it, obesity-related cancers.
- Encouragement of both screening and vaccination to prevent/detect cancer at its earliest stages: Healthcare providers should persuade patients to be vaccinated against HPV and hepatitis B virus, both of which are associated with specific types of cancer. In addition, women should be encouraged to undergo regular PAP screening at age-appropriate intervals, and both men and women should be encouraged to undergo colonoscopy at recommended intervals and to guard against colorectal cancer.
For further information on program and policy interventions that can help promote uptake of both cancer screening and vaccination and prevent cancer-related risk behaviors, healthcare providers may consult the Guide to Community Preventive Services, from the Community Services Task Force, which operates through the support of the CDC.
MMWR Morb Mortal Wkly Rep. Published online July 6, 2017.