Study: US Cancer Screening Rates Declined Over Last Decade

January 4, 2013
Anna Azvolinsky

There has been a decline in overall cancer screening among the US population. Only colorectal cancer screening rates met current screening goals. Cancer survivors specifically met current national screening goals with the exception of cervical cancer screening.

According to a new study, the past decade has seen a decline in overall cancer screening in the United States and have not met desired levels. In the general population, only colorectal cancer screening rates met current screening goals. Survivors had higher rates of screening than the general population and met current national screening goals, with the exception of those for cervical cancer screening.

These are the results of a study published in the journal Frontiers in Cancer Epidemiology and Prevention. Tainya Clarke, MPH, research associate in the department of epidemiology and public health at the University of Miami Miller School of Medicine, and colleagues examined how well the general population and cancer survivors specifically adhered to cancer screening guidelines recommended by the American Cancer Society (ACS).

“The US population needs to improve cervical cancer screening rates. Hopefully we can narrow the gap for the Healthy People 2020 goal of 93%,” said Clarke in an email interview. Clarke highlighted that while the rate of screening among blue-collar workers has increased over the past decade, the growth was not enough to get this group to the nation’s desired screening goal and was lower than rates seen in white-collar workers and service professionals.

“The evident occupational disparities demonstrate that though there have been improvements in the types of benefits available to blue-collar workers, there's still a gap beyond just better education that needs to be filled,” said Clarke. “We need to raise awareness about the benefits of early detection of all cancers amenable to screening.”

Actual screening rates were compared to the national screening goals, called Healthy People 2010, set by the Department of Health and Human Services. More than 174,000 adults participants 18 years and older (including more than 7,500 working cancer survivors) were included in the analysis. Healthy People 2010 baseline statistics were set by January 2000 data with the objective of improving screening rates over 10 years by 10%. The researchers used data, some self-reported, from the National Health Interview Survey from 1997 to 2010.

Breast cancer screening adherence remained steady at 69.7% from 1999 to 2010 according to the analysis. The goal, according to Healthy People 2010, was an overall screening rate of 70% for women 40 years and older. Among cancer survivors, screening rates fluctuated over the decade, decreasing from 2000 to 2003 but increasing to 75.6% in 2010, exceeding the Healthy People 2010 goal. No occupational differences in screening were detected according to cancer history.

Healthy People guidelines are based on selection criteria to reduce or eliminate illness and health disparities and to improve access to healthcare, according to Lila J. Finney Rutten PhD, MPH, of the division of epidemiology at the Mayo Clinic in Rochester, Minnesota, who was not involved in the study. “For cancer screening, the Healthy People objectives are tied to screening procedures for which there has been a scientifically demonstrated benefit for population health,” explained Rutten.

Whether these results are meaningful remain to be seen. Two sets of guidelines for cancer screenings, from the ACS and US Preventive Services Task Force, are available and do not always agree.

Furthermore, recent studies have questioned whether mammogram screenings are actually preventing advanced breast cancer. While mammograms have doubled the number of early-stage breast cancer cases that are detected in the United States, there has not been a reduction in the number of deaths from advanced cancers in the last 30 years. Whether current cancer screening guidelines result in overdiagnosis in some cases needs to be further addressed.

“Although there is emerging evidence of overuse or misuse of cancer screening, few studies have systematically examined this across screening modalities and over time,” said Rutten. “Clearly, in this time of diminishing resources and increasing healthcare expenses, it is crucial to understand how to most efficiently improve the quality of healthcare delivery while reducing cost.”

The US population is getting older and is living longer and those who advocate for more robust screening believe that screening can result in a healthy quality of life later in life. “There are pros and cons to each of the recommended screenings, but most people who take the time to discuss these with their physicians can make informed decisions regarding the benefits of early detection through screening,” said Clarke.

An important takeaway from this study, according to Clarke is that “cancer does not discriminate.” Regardless of a person’s occupation, it is necessary to have access to and education on cancer screening. “It is important to try to flesh out which of the multiple factors affecting screening decisions need the most attention.”

“The observed association between occupation and cancer screening points to the importance of understanding the impact of social determinants of health,” Rutten added. There is now considerable evidence on the disparities of cancer screening based on income, education, insurance status, and race/ethnicity. “Continued efforts are needed to reduce and eliminate these disparities through interventions that have been shown to be effective in increasing the use of screening, including patient reminder systems, removal of structural barriers to access, and system level changes in healthcare delivery,” said Rutten.

While a strength of the current study is the use of national data, questions on the trends of individual adherence to screening over time remain. To partly address this, the Population Health Science Program at the Mayo Clinic is currently studying the longitudinal trend in screening adherence of patients between 2002 and 2011 to better understand not only national but individual-level adherence over time as guidelines evolve.