Disparities in Cancer Risk Factors and Cancer Screening in the United States Part 4

Racial/Ethnic and Socioeconomic Disparities in Obesity and Related Risk Factors

During the past decade, based on the National Health and Nutrition Examination Survey, which has collected objectively measured height and weight information from participants, the obesity (BMI > 30 kg/m2) trends in women have increased nonsignificantly, from 33.4% in 1999-2000 to 36.1% in 2007-2008; among men, the prevalence rose from 27.5% to 32.6% in this period. Compared to White men and women, African American and Hispanic men and women have higher rates of obesity (over 34%) (see Table 3.2). The prevalence of obesity varies slightly with the level of education in men, and strongly with the level of education in women. Prevalence ranges from 23.4% in women with more than 16 years of education to 44.0% in women with 8 or fewer years of education. Variations in obesity prevalence by income are also greater among women than for men (see Table 3.2).

TABLE 3.2 Prevalence of Obesity and Related Risk Factors by Race/Ethnicity, Education Level, and Income Level, Adults 18 and Older, United States

*¹Percent obese in the “16 years" educational category includes also those with more than 16 years of education.

— Data not available due to insufficient sample size.

Compared to White men and women, all racial and ethnic groups show higher levels of inactivity during leisure time. Moreover, there are strong gradients in levels of inactivity during leisure time by income and education status; for example, over half (57%) of those with less education (eighth grade education) report no physical activity while 15% of those with higher education do so (see Table 3.2). However, it should be noted that this survey only collects information on physical activity at leisure and may considerably underestimate total physical activity. Hence, for segments of the population that are employed in industries with physically demanding jobs, a more comprehensive assessment of total physical activity should consider physical activity at both work and leisure.

Currently, the proportion of the adult population that reports consuming five or more fruit or vegetable servings daily is low: 26.2% in women and 18.4% in men. Except in Asian men and women, all race and ethnic groups also show low prevalence levels of fruit and vegetable consumption. Further, there are variations in reported levels of consumption, which are lowest among those at less than twice the poverty rate, and in those who are less educated (see Table 3.2).

Contextual factors that have been described to affect poorer and minority communities include: fewer neighborhood resources, such as inadequate housing; fewer opportunities for safer recreational environments; lower access to fresh foods and healthy nutrition; greater exposure to environmental carcinogens; and selective marketing strategies of tobacco companies and fast-food chains (Kumanyika et al., 2008; Larson, Story, & Nelson, 2008; Ward et al., 2004). Additionally, cultural factors and health literacy, such as attitudes and beliefs about preventive behaviors (Ward et al., 2004), may play a role in health behaviors.

Policies and programs that support healthy behaviors throughout the life cycle are needed to counteract socioenvironmental factors that reduce individuals’ opportunities to eat well and be physically active (Kumanyika et al., 2008; Kushi et al., 2006). Schools and child care facilities, workplaces, and health care facilities are important settings for the implementation of policies and programmatic initiatives. For instance, in the clinical setting, primary care providers play an important role in the clinical management of obesity and in assisting patients on weight management strategies. The appeal of setting-based approaches includes the ability to implement effective strategies to target populations (i.e., students, employees, or patients) and to also influence social norms within the setting, with possible transfer to outside settings through linkage with community-based prevention programs. In order to foster and support public policy and wellness initiatives in schools, workplaces, and communities, the nutrition and physical activity guidelines of the ACS call attention to community action strategies that can lead to improved access to nutritious food or provide safer environments for physical activity. For example, at the state and local level, community leaders can promote policy changes that may include regulation of the school food environments and zoning changes that bring grocery stores into poor neighborhoods (Kumanyika et al., 2008; Kushi et al., 2006).

RACIAL/ETHNIC AND SOCIOECONOMIC DISPARITIES IN CANCER SCREENING

Reducing cancer risk through modifiable lifestyle factors (tobacco use, obesity, nutrition, and physical activity) does not eliminate the risk of disease entirely. Thus, early detection of some chronic conditions could alter the natural history of the disease through implementation of therapeutic interventions that treat either precursor lesions or early-stage disease. Early detection of cancer through established screening methods has been shown to reduce mortality from cancer of the colon and rectum (with the use of the fecal occult blood test and/or endoscopic visual examinations of the large intestine), and uterine cervix (with the Pap test) and breast cancer (with the mammogram) (Smith, Cokkinides, & Brawley, 2009). Screening refers to testing in individuals who are asymptomatic for a particular disease (i.e., they have no symptoms that may indicate the presence of disease) and age is their only (known) factor that puts them at average risk. In addition to detecting cancer early, screening for colorectal or cervical cancers can identify and result in the removal of precan-cerous abnormalities, preventing cancer altogether (Smith et al., 2009).

The ACS publishes updates to cancer screening guidelines for adults at high and at average risk, respectively, on an ongoing basis (Smith et al., 2009; Smith, Cokkinides, Brooks, Saslow, & Brawley, 2010). The ACS screening guidelines for average-risk individuals recommend that all adults age 50 years and older be screened periodically for colorectal cancer, and that women of designated ages be screened regularly for breast and cervical cancer. On the other hand, due to the complexities regarding early detection for prostate cancer screening, the ACS states that men who have at least a 10-year life expectancy should have an opportunity to make an informed decision with their health care provider about whether to be screened for prostate cancer, after receiving information about the benefits, risks, and uncertainties associated with prostate cancer screening. Prostate cancer screening should not occur without an informed decision-making process (Smith et al., 2009).

High rates of screening utilization throughout the population are important to accomplish the goal of reducing the rate of late-stage or advanced cancers, which affects cancer prognosis and survival. Published studies have described the many factors that account for the underutilization of cancer screening in the United States (Smith et al., 2009; Ward et al., 2004, 2008). Of these factors, the prominent ones associated with the receipt of (routine) cancer screening rates are having health insurance status and socioeconomic factors. Another key factor that also influences the use of cancer screening is receiving a recommendation to get screened from a medical health care professional (Smith et al., 2009).

Although 68% of non-Hispanic White women over 40 years of age reported having a mammogram in the past 2 years, only 52.2% reported a mammogram within the past year (see Table 3.3). Since the ACS breast cancer screening guidelines recommend yearly mammograms among averagerisk 40-year-old women, there still remains a large portion of the age-eligible population that does not receive screening regularly, or at all. In addition, mammography usage appears lowest in American Indian/Alaska Native women; only 55.3% had a mammogram within 2 years and only 42.2% in the past year (see Table 3.3). Mammography within the past year was even lower among women who had immigrated to the United States in the past 10 years (39.6%) or who lacked health insurance coverage (26.0%). Rates were only slightly higher for mammography within the past 2 years (49.7% for recent immigrants and 35.6% for women with no health insurance) (see Table 3.3).

The percentage of women aged 18 years and older who reported having a Pap test in the past 3 years was 79.6% in non-Hispanic Whites and 81.5% in African Americans, but lower in Hispanics (75.0%), American Indians/ Alaska Natives (65.2%), and Asians (63.8%), as well as recent immigrants (60.1%) and those with no health insurance (60.6%) (see Table 3.3).

Research supports the use of several screening tests for colorectal cancer, including the less invasive fecal occult blood test (FOBT), on a yearly basis and/or invasive endoscopy procedures (flexible sigmoidoscopy every 5 years or colonoscopy every 10 years) of the lower intestine (Smith et al., 2009). National survey data tracks colorectal cancer screening utilization by total test use (combined FOBT and/or endoscopy) and separately for the two specific tests. However, it should be noted that these surveys may underestimate utilization of colorectal cancer screening, as they do not assess other available testing modalities for colorectal cancer screening, such as double contrast barium enema and the virtual colonoscopy. Relative to other established breast and cervical screening, the utilization of any colorectal cancer screening among adults aged 50 and older is lower—50.2% of women and 54.9% of men reported being up to date with colorectal cancer screening testing in 2008 (see Table 3.3). The use of colorectal cancer screening (by FOBT in the past year) and/or endoscopy in the past 10 years) does not differ by gender, but varies widely by race/ethnicity: the lowest rates are seen among American Indians/Alaska Natives and among Hispanic/Latinos compared with non-Hispanic Whites. In addition, individuals with fewer years of education and no health insurance coverage, and recent (10 years or less) immigrants were the least likely to report having FOBT in the past year or endoscopy within 10 years (see Table 3.3).

It is clear from this data that significant disparities persist in screening among various population subgroups, including non-White, less educated, and lower-income individuals, and those with no access to health care and immigrant status. Though health insurance status is strongly related to use of preventive services, other contextual factors may also influence the use of medical services (i.e., the distribution and accessibility of health services and the medical workforce) (Ward et al., 2008). In addition, based on more indepth investigations of psychosocial factors, there are other potential factors to consider, such as differences in knowledge about cancer prevention, culture, or other barriers to care (Ward et al., 2004). Such cultural and contextual factors should be considered when adapting evidence-based interventions in cancer screening in order to better promote adherence to recommended cancer screening guidelines, particularly among medically underserved populations and vulnerable populations. A number of national initiatives and community-based programs are making contributions in addressing the cancer disparities noted among racial and ethnically diverse populations; for example, the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) is perhaps one of the most visible programs devoted to the early detection of breast cancer among low-income, underinsured, and underserved women.

TABLE 3.3 Prevalent Use of Cancer Screening by Selected Characteristics, Adults, National Health Interview Survey, 2008

Percentages are adjusted to the 2000 U.S. standard population.

^aFecal occult blood test: a home fecal occult blood test within the past year.

^bEndoscopy: a sigmoidoscopy test within the past 5 years or a colonoscopy within the past 10 years.

^cCombined FOBT/endoscopy: a fecal occult blood test within the past year, a sigmoidoscopy test within the past 5 years, or a colonoscopy within the past 10 years. Estimates should be interpreted with caution because of small sample size.

—Data not applicable.

Clinicians and the health care systems play a major role in enabling patient participation in cancer screening. For example, studies have shown that people who receive a clinician’s recommendation for cancer screening are more likely to be screened than those who do not receive a recommendation ("Recommendations," 2008). The Task Force on Community Preventive Services recommends that to maximize the potential impact of interventions for improving cancer screening, a diverse set of strategies should be implemented. These include centralized or office-based systems, including computer-based reminder systems, to assist clinicians in counseling age-/ risk-eligible patients about screening, as well as organizational support systems to help manage referrals and follow-up of cancer screening tests ("Recommendations," 2008). In addition, as people who lack health insurance have less access to preventive care and are less likely to get timely cancer screening, access to affordable, quality health care continues to be a fundamental policy priority. The newly enacted health care reform legislation includes several provisions (i.e., increasing the emphasis on prevention services) that will likely improve access to and the quality of health care to many Americans.

Disparities in health outcomes will persist as long as large segments of the U.S. population have limited or no access to prevention and early detection intervention programs. There is a need to build programs for prevention and early detection based on the existing research evidence. With more systematic and targeted efforts to reduce tobacco use, improve diet and physical activity, reduce obesity, and expand the use of established screening tests, there is a great potential to further prevent cancer and save lives.