Associations between perceived cancer risk and established risk factors in a national community sample
Introduction
Either as an integral component of a well-articulated model of health behaviors—the health belief model [1], [2] and protection motivation theory [3]—or as a stand-alone variable in empirical investigation, perceived cancer risk has attracted considerable research attention in the cancer control field. Perceived cancer risk, defined as the subjective estimation of the likelihood that one might be diagnosed with cancer in the future [2], has played a pivotal role in understanding the processes that predict adherence to a diverse range of cancer screening behaviors, including screening mammography, skin cancer screening and colorectal cancer screening [4], [5], [6], [7], [8], [9]. Perceived personal cancer risk has also been studied as a dependent variable to promote understanding of sources underlying risk perceptions [10], [11], [12], [13], [14], [15], [16], in which family history, race/ethnicity, current physical symptoms, psychological distress, knowledge of cancer, and smoking status were found to be predictors of personal cancer risk perception, although these findings were inconsistent due to the heterogeneity of the study samples, variables collected and analytic approaches used.
Some studies to date in the United States and elsewhere have studied to what extent widely publicized established risk factors influence individual awareness and knowledge of such risk factors [17], [18], [19], [20], [21], [22], [23]. While a myriad of contextual factors can shape individuals’ perceptions of cancer risk, exposure to public campaigns that attempt to raise awareness of known risk factors may influence public risk awareness and knowledge. For example, a French study [18] found that individuals’ judgments about the relationship between the amount of cigarette smoking and their perceived risk of lung cancer corresponded with their true epidemiologic risk. Similar studies in the United Kingdom [17], [19] found that subjects who were female, had a higher income or had more years of education had an increased awareness of widely publicized warning signs or established risk factors of cancer. Similar findings were reported in a study using a representative sample of American adults [21] which highlights that lack of knowledge about risk factors was pervasive across all different ages, race, socioeconomic groups and particularly apparent among the disadvantaged. Arguably, lack of awareness and knowledge about established risk factors may influence one’s personal risk perception and comprehension.
There is little understanding about each individual’s perceived cancer risk and its association with exposure to objective risk factors. While efforts to narrow the gap between actual and perceived cancer risk are important to promote better screening decisions by individuals [24], [25], mathematical models of cancer risk estimation, such as the Gail Model [26] or BRCAPRO model [27], are often poorly correlated to perceived cancer risk [10], [28], [29], [30]. One of the possible reasons for the discrepancies may be the assumption that an individual’s judgment about one’s own cancer risk depends on a complex set of personal beliefs influenced not only by medical factors but also by contextual factors [25]. For example, Kristeller et al. [31] found that cancer patients and their relatives cited stress as the most important cause of their cancer, followed by bad luck, heredity, and environmental pollution, and, to a lesser extent, modifiable risk factors, such as diet and alcohol. Others found a positive association between risk perception and psychological distress such as fear, anxiety, and depression [14], [32], [33], [34], [35], indicating a significant affective–cognitive relationship between the two. Similarly, one study examining cancer screening adherence following the familial-genetic assessment found that adherent patients were either underestimators or accurate estimators, while most of the non-adherent patients were either overestimators or accurate estimators, indicating that perceived cancer risk might have functioned as a proxy for specific distress and anxiety related to cancer [36]. Thus, measurement of perceived risk could be clouded by underlying specific psychological distress related to cancer risk estimation. These findings support the notion that potential psychological intervening mechanisms, such as orientation toward uncertainty (e.g. fatalism) and anxiety, may underlie and explain differential self-appraisal of cancer risk [37]. Furthermore, recent findings on racial/ethnic differences in perceived cancer risk [14], [15], [38] underscore the importance of understanding the cultural influence on risk perceptions.
While different kinds of cancer have different risk factors, major established risk factors include non-modifiable factors, such as family history, advanced age, gender, race, and lower socioeconomic status, as well as modifiable risk factors, such as cigarette smoking, physical inactivity, excess alcohol intake, and overweight/obesity [39]. All these risk factors were included in this study, but not exposure to poor diet, infectious disease, and environmental pollution due to the constraints of the data analyzed. While the degree of evidence for each of these risk factors varies, it is widely accepted that cigarette smoking is a critical factor in carcinogenesis, accounting for at least 30% of all cancer deaths and 87% of lung cancer deaths [40]. Obesity and overweight have been linked to cancer morbidity [41] and mortality [42], and estimated to account for 5% of new cancer cases in Europe and 14–20% of cancer deaths in the United States. Although the evidence is weaker for other modifiable risk factors than for smoking and obesity/overweight, increasing evidence suggests that physical inactivity and alcohol drinking may increase a person’s chances of developing cancer at specific sites [40], [43], [44].
The aim of the present study was to develop a knowledge base through the examination of associations between major established risk factors and perceived cancer risk in a representative sample of asymptomatic adult populations in the United States. The following question was addressed: to what extent do such major established risk factors, independently and in combination, affect variations in perceived cancer risk among asymptomatic adults?
Section snippets
Sample
We used data from the Sample Adult file of the 2000 National Health Interview Survey (NHIS). The NHIS is based on a national probability sample survey conducted by household interview; the methodology has been described elsewhere [45]. With appropriate sampling weights, the data were representative of the entire US adult population and included a total of 32,374 civilian non-institutionalized US residents older than 18 years. After eliminating respondents who were diagnosed with cancer,
Results
Table 1 presents the overall prevalence of perceived cancer risk as well as the prevalence by each of established cancer risk characteristics. Bivariate associations between perceived cancer risk and each characteristic were examined by chi-square test (Table 1). Overall, about half (52.9%) of adults without cancer diagnosis rated their risk of cancer as low, while 27.7% perceived medium and 8.7% perceived high. 10.6% of respondents were uncertain about their cancer risk and the analysis of
Discussion
The current study used a national representative sample to identify critical gaps between perceived cancer risk and established risk factors in the general population, providing a focus for educational strategies. We found that the relationship between perceived cancer risk and established risk factors differs in important ways from what public campaigns have communicated with the public.
Despite the fact that the actual risk of cancer increases with advancing age, age was inversely associated
Acknowledgements
Dr. Honda is a postdoctoral fellow on an NCI-funded T32 Training Grant (CA09529). Dr. Neugut is the recipient of a K05 Award from the National Cancer Institute (CA89155). Authors thank Dr. Ethel Mitty for her helpful comments on earlier drafts.
References (55)
- et al.
What promotes skin self-examination?
J. Am. Acad. Dermatol.
(1998) - et al.
Psychosocial influences on older adults’ interest in participating in bowel cancer screening
Prev. Med.
(2000) - et al.
Family and friends with disease: their impact on perceived risk
Prev. Med.
(2003) - et al.
Awareness of risk factors for cancer among British adults
Public Health
(2001) - et al.
Relationship between cigarette dose and perceived risk of lung cancer
Prev. Med.
(1999) - et al.
Americans’ knowledge of cancer risk and survival
Prev. Med.
(1997) - et al.
Knowledge, attitudes and behavioral intentions in relation to early detection of colorectal cancer in the United Kingdom
Prev. Med.
(2003) - et al.
Knowledge and perceptions about breast cancer incidence, fatality and risk among Australian women
Aust. N Z J. Public Health
(1999) - et al.
Attitudes toward risk factor behavior of relatives of cancer patients
Prev. Med.
(1996) - et al.
Psychological adjustment to familial-genetic risk assessment for ovarian cancer: predictors of nonadherence to surveillance recommendations
Gynecol. Oncol.
(2002)