MedicalResearch: What is the context of the study?
- It has long been known that poverty is associated with adverse health conditions. In general, increasing poverty results in higher disease rates and higher mortality.
- This study assessed the relationship between poverty and cancer incidence using national cancer data on nearly 3 million tumors from the North American Association of Central Cancer Registries (NAACCR).
- Cancer registries do not collect economic information on cancer patients, so we used an area-based social measure: % of persons living below poverty within a census tract. This measure is a proxy for an individual’s economic status and also gives insight into the type of neighborhood in which an individual lives.
MedicalResearch: What are the main findings of the study?
- Cancer effects both the rich and the poor. However, socioeconomic status influences the type of cancer a person may develop.
- There were 32 specific cancer sites that showed a statistically significant relationship with poverty—14 sites had rates that increased with increasing area-based poverty, including HPV-related cancers, like cervical, and tobacco-associated cancers, like lung. And 18 sites had rates that decreased with increasing area-based poverty, including breast and prostate cancers. This relationship held true for the majority of cancer sites regardless of race.
- In general, rates of cancers associated with behavioral risk factors such as tobacco, alcohol and IV drug use, sexually transmitted disease, and poor diet tend to increase with increasing area-based poverty.
- In general, rates of cancers associated with over-diagnosis, that is cancers detected due to use of medical technology that would not have been identified otherwise, tend to increase with increasing area-based affluence.
- Cancers more associated with poverty have lower incidence and higher mortality. Cancers more associated with wealth have higher incidence and lower mortality. This means people living in affluent areas get higher rates of cancer, but people living in poorer areas are more likely to die of their cancer.
MedicalResearch: Were any of the findings unexpected?
- While the results corroborate prior research, this study is the most comprehensive evaluation of cancer incidence and poverty conducted in the United States to date.
MedicalResearch: What should clinicians and patients take away from your report?
- Health disparities are a result of unequal distribution of health risks that have social, economic, and cultural roots that drive both individual behavior and macro level exposures.
- Effective, community-based public health programs targeting low-income neighborhoods may reduce mortality among people living in poverty.
MedicalResearch: What recommendations do you have for future research as a result of this study?
- This study demonstrates the importance of including measures of socioeconomic status in national cancer surveillance.
- Socioeconomic status in an integral and complex determinant of individual health and the health of populations. Further research is needed to identify effective public health programs and points of intervention to reduce these noted health disparities.
- Research into reducing overdiagnosis, and subsequent overtreatment, without sacrificing clinically important early detection is also needed.
Francis P. Boscoe, Christopher J. Johnson, Recinda L. Sherman, David G. Stinchcomb, Ge Lin, Kevin A. Henry. The relationship between area poverty rate and site-specific cancer incidence in the United States. Cancer, 2014; DOI: 10.1002/cncr.28632