The overall cancer death rate in the U.S. dropped by 27% over the past 25 years, but more needs to be done to reduce deaths among Americans of lower socioeconomic status, according to a report from the American Cancer Society (ACS) published online January 7 in CA: A Cancer Journal for Clinicians.
Despite 2.6 million fewer cancer deaths between 1991 and 2016, mortality rates are, for example, twice as high for cervical cancer in poorer U.S. counties than in more affluent areas. Rates are also 40% higher for male lung and liver cancers and 35% higher for male colorectal cancer, according to ACS researchers led by Rebecca Siegel.
"Although the racial gap in cancer mortality is slowly narrowing, socioeconomic inequalities are widening, with the most notable gaps for the most preventable cancers," wrote Siegel and colleagues.
Siegel's team found that steady reductions in smoking and advances in early detection and treatment have contributed to the decrease in cancer mortality over the past two decades. These developments are also reflected in lower mortality rates for lung, breast, prostate, and colorectal cancers:
- The lung cancer mortality rate declined by 48% from 1990 to 2016 among men and by 23% from 2002 to 2016 among women.
- The female breast cancer mortality rate dropped by 40% from 1989 to 2016.
- The prostate cancer mortality rate decreased 51% from 1993 to 2016.
- The colorectal cancer mortality rate dropped by 53% from 1970 to 2016.
However, the death rates for some cancers increased between 2012 and 2016, Siegel and colleagues noted. The liver cancer death rate increased by 1.2% per year in men and 2.6% per year in women, the pancreatic cancer death rate (in men only) increased by 0.3% per year, and endometrial cancers increased by 2.1% per year. For 2019, the authors estimate that 1.8 million new cancer cases and 606,880 cancer deaths will occur in the U.S.
Yet, despite an overall decrease in cancer deaths and a diminished racial gap in cancer mortality, socioeconomic inequalities are growing. In fact, a recent study estimated that 34% of cancer deaths in Americans 25 to 74 years old could be avoided by eliminating socioeconomic disparities, according to the group.
"The prevalence of behaviors that increase cancer incidence and mortality are vastly higher among residents of the poorest counties, including double the prevalence of smoking and obesity compared to residents of the wealthiest counties," the researchers wrote. "Poverty is also associated with lower cancer screening prevalence, later stage diagnosis, and a lower likelihood of optimal treatment."
The report findings highlight the need for more efforts to reduce healthcare discrepancies, the investigators concluded.
"Some states are home to both the poorest and the most affluent counties, suggesting an opportunity for improvement in the distribution of services. ... Numerous states have reduced inequalities through various strategies that removed barriers to prevention, early detection, and treatment," they wrote.
