While more people are surviving cancer than ever before, not everyone is benefiting from advances in prevention, diagnosis and treatment.
The American Cancer Society’s Cancer Statistics 2019 shows overall cancer mortality dropped 27% between 1991 and 2016. But between 2012 and 2016, the rate was approximately 20% higher among residents of the US’ poorest counties than those of the most affluent.
“Although the racial gap in cancer mortality is slowly narrowing, socioeconomic inequalities are widening, with the most notable gaps for the most preventable cancers,” says the report, which was published in CA: A Cancer Journal for Clinicians in early January.
The residents of the poorest counties in the US are experiencing an “increasingly disproportionate burden”, it adds, with the largest health disparities in lung, breast, prostate and colorectal cancer.
It is the prevention of these cancers that has been largely credited with the overall decline in deaths.
Preventable cancers, preventable deaths
Compared with the most affluent counties, mortality rates in the poorest counties were twofold higher for cervical cancer and 40% higher for male lung and liver cancers between 2012 and 2016.
The most striking socioeconomic shift has occurred in colorectal cancer (CRC). In the early 1970s, CRC death rates in the poorest counties were approximately 20% lower than those in affluent counties. Now they are 35% higher.
The reversal, the authors suggest, reflects changes in the dietary and smoking patterns that influence CRC risk, as well as the slower dissemination of screening and treatment advances among disadvantaged populations.
“In contemporary times, 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,” it notes.
“Poverty is also associated with lower cancer screening prevalence, later stage diagnosis, and a lower likelihood of optimal treatment.”
This is borne out by the fact that such outcome disparities are either reduced or absent in cancers that are less amenable to prevention or treatment. In leukemia and non-Hodgkin lymphoma, for example, mortality rates were equivalent across poverty levels.
Leveling the playing field
While these disparities are concerning, they are reversable, particularly in mixed socioeconomic areas, by increasing access to healthcare and education, suggests the report.
“Although lack of healthcare capacity in economically challenged areas likely contributes to these disparities, some states are home to both the poorest and most affluent counties, suggesting an opportunity for improvement in the distribution of services,” write the authors.
While the continuous decline in cancer mortality over the last 27 years has led to an estimated 2.6 million fewer deaths in the USA, there is still work to be done to reduce the burden of the disease.
Tackling socioeconomic health disparities could help in this effort, the report argues.
“(Poor) counties are low-hanging fruit for locally focused cancer control efforts, including increased access to basic healthcare and interventions for smoking cessation, healthy living, and cancer screening programs.”
“A broader application of existing cancer control knowledge with an emphasis on disadvantaged groups would undoubtedly accelerate progress against cancer,” it concludes.
Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin 2019; 69:7-34