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‘Eye-opening’ disparities observed in rates of cancer risk factors
Although cancer death rates in the U.S. continue to decline, biennial research from the American Cancer Society shows that nearly half of all cancer deaths involve disease with known modifiable risk factors.
The research — published in Cancer Epidemiology, Biomarkers & Prevention — shows that rates of certain modifiable cancer-risk factors varied substantially along racial/ethnic and educational achievement lines.
“Although we’ve examined disparities in cancer risk factors and early detection in the past, the degree of the disparities is eye-opening,” Ann Goding Sauer, MSPH, epidemiologist and senior associate scientist at the American Cancer Society, told HemOnc Today. “For example, the prevalence of cigarette smoking among men without a high school degree was six times higher than among female college graduates. Also, less than 50% of those without a high school degree were up to date with colorectal cancer screening compared to more than 70% of college graduates.”
There has been some progress in reducing the overall prevalence of cancer-related risk factors since Goding Sauer started tracking these data, she said, pointing out that overall smoking rates have decreased along with indoor tanning among teens, which leads to increased UV radiation exposure. However, obesity is one risk factor that has increased over time among the U.S. population.
American Cancer Society researchers used national survey data to update its biennial report, “Cancer Prevention and Early Detection Facts & Figures,” through 2017. It includes data from the National Health Interview Survey, Behavioral Risk Factor Surveillance System, National Health and Nutrition Examination Survey, and National Immunization Survey-Teen.
“Assessing the most current prevalence of cancer risk factors, vaccination and screening is an important component of monitoring progress and strengthening cancer control efforts,” Goding Sauer and colleagues wrote.
Tobacco use
The rate of smoking in the U.S. continued to decline in 2017, with approximately 34 million adults (14.1% overall; 16% of men, 12.3% of women) considered current cigarette smokers.
The smoking rate, however, is markedly higher among certain populations. For example, rates were highest among American Indians (27.3%) and Alaska Natives (21.5%) than among Asians, who had the lowest smoking rate (10.6% of men, 3.6% of women) when broken down by race/ethnicity.
Five percent of female college graduates smoked compared with 30% of white men with less than a high school education.
Location also appears to be associated with cigarette use.
“In 12 states, 20% or more of adults, males and females, continue to smoke,” Goding Sauer told HemOnc Today.
Her group’s research shows that overall smoking rates in the U.S. are higher in the South (15.7%) and Midwest (17.1%), and relatively lower in the Northeast (11.3%) and West (11.1%).
Body weight, physical activity
The proportion of those considered obese (BMI 30 kg/m2) in the U.S. has increased substantially over time, according to the researchers. They noted that, from 1960 to 1962, 10.7% of men and 15.8% of women were obese. This increased to 37.9% of men and 41.1% of women between 2015 and 2016.
Disparities in obesity rates also exist among racial and ethnic groups. More than half of black (54.9%) and Hispanic (50.6%) women were obese, compared with 38% of white women.
Further, more than a quarter of adults in the U.S. reported a lack of nonwork-related physical activity in 2017. The proportion increased to 48.7% among those with less than a high school education compared with 14.4% of those with a college degree.
Researchers also observed disparities by sex and race/ethnicity, although to a lesser degree. More Hispanic (34.3%) and black (31.3%) men reported a lack of leisure-time physical activity than white men (21%); the same held true for black (38.3%) and Hispanic (37.2%) women compared with white women (22.9%).
UV radiation
The percentage of adults who engaged in indoor tanning decreased from 5.5% in 2010 to 3.6% in 2015. Men and women reported similar rates (35.5% vs. 35.4%) of at least one sunburn over the past year during 2015; however, those with higher levels of education were more likely (range, 31%-39%) to report at least one sunburn than those with less than a high school education (19.7%).
The researchers noted that approximately three-quarters of women used at least one preventive measure against sun-related damage, compared with two-thirds of men.
Infectious diseases
The researchers noted that, as of 2017, HPV vaccination is increasing among those younger than 18 years. In 2017, 53.1% of girls and 44.3% of boys aged 13 to 17 years were up to date on HPV vaccination — far below a recommended goal of 80%.
Data from the same year show that 41.7% of girls and only 30.6% of boys were up to date on HPV vaccination by age 13 years. More than 90% of all adolescents received three or more hepatitis B vaccine doses as of 2017, yet only 24.6% of adults aged 19 years and older received three doses of the vaccine.
Cancer screening
Seventy-one percent of women aged 50 to 74 years reported having a mammogram during the last two years. This number decreased to 55% among women 45 years of age and older with less than a high school education, compared with 77.5% of female college graduates.
The same disparity was observed for cervical cancer screenings. The proportion of women who were up to date on cervical cancer screenings was substantially lower among those with less than a high school education vs. among college graduates (71.7% vs. 90.5%).
Overall, 62.6% of men aged 50 years and older were up to date on colorectal cancer screenings.
Researchers also noted disparities in colorectal cancer screening rates along educational lines. Less than half (47.4%) of men with less than a high school education had up-to-date colorectal cancer screenings, compared with 71.3% of men with a college degree. Colorectal screening was also less frequent among Hispanic (49.9%) and Asian (49.4%) men compared with black (61.8%) and white (65.4%) men.
“There are several barriers to receiving cancer screening, insurance being one of them,” Goding Sauer told HemOnc Today. “But, there are also logistical and cultural barriers to screening, which may also influence risk factors.”
Public health implications
The researchers observed that, overall, both men and women with lower levels of education had an increased prevalence of the modifiable cancer risk factors they evaluated in the American Cancer Society report, and were less likely to undergo cancer screenings.
“Reducing these modiable cancer risk factors and improving cancer screening will require broad implementation of national, state and local policies, social/community efforts, as well as individual behavioral interventions,” Goding Sauer and colleagues wrote.
Their review was limited by recall and social-desirability biases, the investigators wrote. For example, they noted that self-reported mammography rates historically have been overestimated among racial/ethnic minorities, which can cause disparities in the data.
“Focused cancer prevention and control efforts to reduce tobacco use and [excess body weight] and increase screening and vaccination uptake are necessary to further reduce the suffering and death from cancer,” the authors wrote. “Such systematic efforts should be enhanced across all populations, particularly those most at risk, including those with lower [socioeconomic status] and racial/ethnic minorities.”– by Drew Amorosi
For more information:
Ann Goding Sauer, MSPH, can be reached at American Cancer Society, 250 Williams St., Atlanta, GA 30303; email: ann.godingsauer@cancer.org.
Disclosures: The authors report no relevant financial disclosures.