Nearly Half of Cancer Deaths Attributable to Modifiable Risk Factors

Cancer mortality continues to decline in the United States. Despite this progress, approximately 45% of the 607,000 cancer deaths expected to occur in 2019 will be related to modifiable risk factors, including smoking, obesity, and lack of cancer screening.

These findings come from an analysis of population-based surveys, which also found that the prevalence of these risk factors varies among racial/ethnic groups, as well as education level. The surveys, which included the National Health Interview Survey and the Behavioral Risk Factor Survey, captured data through 2017.

“Reducing these modifiable 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,” wrote the researchers. “Many of these strategies have been proven to be effective, but their application has been suboptimal, especially in socioeconomically deprived populations.”

Tobacco use

Overall, cigarette smoking accounts for approximately 29% of cancer deaths. While smoking rates have decreased, smoking prevalence remains significantly higher in certain populations, ranging from 5% of women who graduated college to 30.1% of men with less than a high school education. Among both men and women, smoking was least prevalent among Asians (10.6% and 3.6%, respectively) and highest among American Indian/Alaska Natives (27.3% and 21.5%, respectively).

The report also looked at e-cigarette use, which has dramatically increased in recent years, particularly among adolescents and young adults, and has faced increased scrutiny from federal officials, most notably former FDA Commissioner Scott Gottlieb, MD. In 2017, 2.9% of adults reported using e-cigarettes, with racial/ethnic (Hispanic: 1.6%; white: 3.7%) and education level (college: 1.4%; high school: 3.9%) differences observed.

Excess body weight, alcohol, and physical activity

An estimated 16% of cancer deaths are a result of a combination of overweight and obesity, excess alcohol consumption, poor diet, and lack of physical activity.

While the prevalence of overweight has remained stable over recent years, in 36.5% of men and 26.9% of women, the prevalence of obesity has drastically increased, with 7 states having obesity rates of at least 35% in 2017, up from 0 states in 2012. The report also highlighted significant disparities with obesity rates, with more than half of Hispanic (50.6%) and black (54.9%) women being obese, compared with 38% of white women and 14.8% of Asian women.

In 2017, 5.3% of adults were considered heavier drinkers, with a higher prevalence among white men and women. Heavy drinking was defined as more than 14 drinks per week for men and more than 7 drinks per week for women over the past year.

Approximately 26% of adults reported no physical activity, which ranged from nearly 50% of adults with less than a high school education to 14.4% of college graduates. Racial/ethnic disparities were also observed but were less pronounced and varied by gender. Hispanic (34.3%) and black (31.3%) men were more likely to be inactive compared with whites (21%), Asians (21.2%), and American Indian/Alaska Natives (36.5%). Hispanic (37.2%), black (38.3%), and American Indian/Alaska Native women (36.5%) were more likely to be inactive than Asians (28.6%) and whites (22.9%).

Cancer screening

Among women aged 50 to 74, 71% reported having a mammogram within the past 2 years. Less than 65% of Hispanic, American Indian/Alaska Native, and Asian women reported having a mammogram compared with 68.4% of white and 71% of black women, and college graduates were significantly more likely to report having a mammogram. Similar findings were seen with cervical cancer screening.

Colorectal cancer screening increased significantly from less than 40% in 2000 to 62.5% in 2015. Education seemed to play a significant role in colorectal cancer screening, with less than half of adults with less than a high school education being screened compared with 71.3% of adults with a college degree. Racial/ethnic disparities were also observed, with less than half of Hispanics and Asians being screened compared with 54.3% of American Indian/Alaska Natives, 61.8% of blacks, and 65.4% of whites.

In 2015, approximately one third (34.4%) of men over 50 reported having a prostate-specific antigen test within the past year. However, the report notes that until 2018, the United States Preventive Services Task Force recommended that asymptomatic men not be routinely screened.

Reference:

Sauer A, Siegel R, Jemal A, Fedewa S/ Current prevalence of major cancer risk factors and screening test use in the United States: disparities by education and race/ethnicity [published online April 10, 2019]. Cancer Epidemiol Biomarkers Prev. doi: 10.1158/1055-9965.EPI-18-1169.