1. Introduction

Currently, approximately 900 genetic tests are available for screening, identifying susceptibility and diagnosing various disease conditions ^[1]. A genetic test for lung cancer susceptibility is one such test. Given that reducing mortality and morbidity associated with lung cancer is an important national priority ^[2], studies show that genetic tests for lung cancer risk could help improve preventative behaviors such as increased usage of smoking cessation services and higher quit rates/intention to quit among smokers and early detection screening ^{[3, 4]}. While the merits of the utility of a genetic test for identifying lung cancer risk are still being debated ^{[5, 6]}, the growing market for genetic tests suggests that these tests will be soon be widely and easily accessible to the general public, particularly through the use of internet. Already, companies developing these tests have begun marketing them, with little or no regulation of outcome claims ^[7].

Many studies have examined public interest and ultimately use of genetic testing for cancer risks. A majority of these studies have focused on genetic testing for breast, ovarian and colon cancer risk [8-13]^[8]. Research examining public interest in genetic tests for lung cancer risk is sparse and focused mainly on high-risk populations, such as smokers ^{[4, 14]} and relatives of lung cancer patients ^[15]. Although as of now, the genetic test for lung cancer susceptibility is mainly used or promoted for smokers, a lot of health decisions are influenced by friends and family. Hence, exploring the perceptions of general population, who may be former smokers, current smokers or non-smokers connected to smokers, is extremely valuable if informed decisions are to be made about whether or not to utilize genetic tests for lung cancer. In order to create well defined, targeted educational programs, assessment of the public’s awareness, perception and intention to use genetic tests for lung cancer risk must be conducted. Therefore, the objective of this study is to assess public awareness, perceptions and intention to use genetic testing for the susceptibility to lung cancer as well as identifying the factors which may affect intention to use a genetic test to screen for lung cancer risk.

2. Methods

The Health Belief Model (HBM) ^[16] served as the theoretical basis for developing the conceptual framework of this study. A diagrammatic representation of the conceptual framework is presented in Figure 1. In addition to the HBM constructs, several additional variables were included from relevant literature. For example, awareness of genetic testing, family history and smoking habits have often been discussed in the literature as important variables associated with intention to use genetic tests [11,13,17-24]. Also, demographic variables such as gender, education, age and ethnicity were other factors that appear to be related to awareness and intention to use genetic testing, were included ^{[10, 18, 20, 22, 25, 26]}. The main outcome variable for the study was intention to use a genetic test in order to assess lung cancer risk. The independent variables were individual awareness that these tests exist; perceived beliefs of individual susceptibility to developing lung cancer; individual knowledge of the severity of lung cancer; barriers to getting genetically tested; and benefits to getting tested. In addition to demographic factors, including family history and smoking habits were examined.

Figure 1. Diagrammatic Representation of Conceptual Framework

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A cross-sectional survey design was used for this pilot study. Researchers approached individuals 18 years or older, in central business and commercial areas such as city halls, shopping plazas, bus and train stations, during different times of the day, and in the three densely populated cities in the northern, central and southern regions of New Jersey, Newark, Elizabeth and Toms River. A sample size of 360 was determined using Cochran’s equation for maximum variability ^[27], and a convenience sampling strategy was used. The study protocol was approved by the investigator’s University Institutional Review Board. After informing participants of the purpose of the study. they received a copy of the survey.

Intention to use genetic tests for lung cancer risk was measured using a 2-item scale adapted from O’Connor and White (2009) ^[28] and measured participants’ intention to use a genetic test for assessing lung cancer risk in two time frames (in the next 2 months, and in the next 1 year), using a Likert scale (1=strongly disagree to 5=strongly agree). Awareness of the existence of genetic tests was measured using a 5-item scale adapted from Bunn et al (2002) ^[13], which measured general awareness about genetic tests and availability of genetic tests for detecting breast, colon, prostate, and lung cancer risk, using a dichotomous response set (Yes/No). The participant’s Perceived susceptibility of lung cancer was measured using a 7-item scale developed from items used by Smith and Croyle (1995) ^[29], Sanderson et al (2004) ^[30], and Nexoe et al (1999) ^[31], that used a Likert scale (1=strongly disagree to 5=strongly agree). Perceived severity of lung cancer was measured using a 3-item scale adapted from Nexoe (1999) ^[31], that used a Likert scale (1=strongly disagree to 5=strongly agree).

Perceived barriers to using lung cancer genetic test was measured using a 9-item scale developed from items used by Smith and Croyle (1995) ^[29], Sanderson et al (2004) ^[30], Nexoe et al (1999) ^[31], and Bunn et al (2002) ^[13], using a 5-point Likert scale (1=strongly disagree to 5=strongly agree). Perceived benefits of using lung cancer genetic test was measured using a 4-item scale developed from items used by Hahn et al (2006) ^[32], and Bunn et al (2002) ^[13], that used a Likert scale (1=strongly disagree to 5=strongly agree).

In addition to these, standard survey items were used to assess age, gender, race/ethnicity, education and family history of lung cancer. Family history of lung cancer was measured based on how closely related the participant was to the diagnosed relative, such as, first degree relative, second degree relative, distant relative. Participants were asked to choose the best suitable option provided.

All completed survey data were screened for completeness and entered into SPSS version 17.0. Descriptive, reliability, factor, and regression analyses were conducted. For descriptive analysis, individual item frequencies, means and standard deviation were calculated. Total mean scores were calculated for each scale by summating responses on all items within the scale. These total mean scores were used to conduct regression analyses using a statistical significance of P<0.05.

3. Results

A total of 390 of 620 residents approached participated in the study (62.9% response rate). Of these, 360 (58%) had complete responses. Participants varied in age, race and education. Over half (52%) were female; 52% also had an annual income of less than $50,000; 60% were nonsmokers; and 67% had no family history of lung cancer (Table 1). Median age, education and gender were comparable to that of the general United States population, and comparable to the New Jersey population in terms of median age and gender (US Census 2011). The exploratory factor analysis and reliability analysis as described in Table 2 showed that the scales utilized in the study had excellent psychometric properties.

Table 1. Demographics

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Individual item and scale mean scores for each measure used in this study are presented in Table 3. Overall, less than one-third (28.6%) of participants were aware of genetic testing. The highest awareness was for availability of genetic tests for the risk of breast cancer (63%), and the lowest for the risk of lung cancer (55.8%).

Participants perceived their susceptibility to lung cancer to be moderate, with items related to perceived susceptibility of lung cancer for smokers demonstrating higher means when compared to other items in the susceptibility scale. This suggested that most people in the study believed smokers were at higher risk for lung cancer. Participants perceived moderate barriers to using genetic testing for lung cancer. These barriers were related to the financial burden of purchasing and using the test. In addition, apprehension of being at high risk to develop lung cancer was itself a barrier. Only about 35% of participants intended to use genetic testing within the next 2 months, whereas about 43% intended to use it within the next 1 year, indicating the overall intention and interest in the test was moderate.

Table 2. Results of Exploratory Factor Analysis of Study Scales (Factor loadings and communalities based on a principle components analysis with varimax rotation)

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Table 3. Descriptive Analysis of Study Variables

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Two linear regression models were used to examine and identify predictors of intention to use genetic testing for the risk of lung cancer. The first model examined the demographic predictors (Gender, Age, Ethnicity, Education, Annual Income, Number of Household Smokers, Lung Cancer Family History, Smoking Habits) to predict intention to use genetic testing to evaluate participants’ perceived risk of lung cancer. The model accounted for 10% of variance in intention of using genetic testing for the risk of lung cancer among participants. As shown in Table 4, Gender (β=-0.441, α=0.032), Education (β=-0.246, α=0.001), and Smoking Habits (Non-Smokers, β=-0.589, α=0.029) were found to be significant predictors. This suggested that participants who were male, high school educated, and smokers had greater intention to use genetic testing for the risk of lung cancer. The second model identified whether awareness and perceived beliefs (susceptibility, severity, barriers and benefits) were significant predictors of intention to use genetic testing. In this model, perceived benefits (β=0.174, α=0.000) was the only significant variable to predict intention. This suggested participants who believed genetic testing was more beneficial demonstrated greater intention to use it for the lung cancer risk. These variables accounted for 7.8% variance in intention among participants to use the test for the risk of lung cancer.

Table 4. Results from Regression Analysis

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4. Discussion

Almost half of the participants were aware that genetic tests existed for the risk of various cancers, which is similar to prior studies ^{[13, 23]}. However, awareness was lowest for the availability of genetic testing for the risk of lung cancer. This may be because genetic tests for lung cancer risk have only recently been advertised, and primarily advertised to smokers. Overall, the participants perceived themselves as moderately susceptible to lung cancer. This is unlike other population-based studies which showed higher perceived susceptibility to breast and colon cancer ^{[13, 17]}. Perceived susceptibility in this study may have been moderate because it is mostly believed that only smoking is the cause of lung cancer ^[33], and the sample constituted about 77% former- and non-smokers. This is important because smoking is one of the biggest risk factors for lung cancer, but not the only risk factor. Thus, it appears that there is a need for programs that educate the public’s understanding of the risk factors for lung cancer (besides smoking).

The majority of participants believed that genetic testing is beneficial. Similar to previous studies, benefits to family members were perceived as the most important benefit of conducting this test ^{[9, 17]}. Future qualitative studies should examine reasoning behind this perception and the added advantage of using genetic testing. Participants agreed that one of the major barriers for not seeking genetic testing was the cost of the test. Previous studies also reported financial costs as a major obstacle to genetic testing ^{[9, 17, 23]}. Companies manufacturing genetic tests and health insurance agencies promoting the use of genetic tests, may need to examine strategies to mitigate cost related concerns.

The overall intention to use genetic testing for the risk of lung cancer was low. This differs from other studies which found higher interest in being screened ^{[32, 34]}. This may be explained by the fact that the population in this study was mostly nonsmokers from the general population, whereas previous studies examined high-risk populations. Future studies may want to consider a similar methodology using primarily smokers. Although no known study looked at intention among the general population, studies on smokers found smoking habits (number of cigarettes smoked) impacted interest in screening information and being screened ^[32]. Gender and education were significant factors in determining participants’ intention to use genetic testing.. In a previous study ^[22], education was also found to be a predictor of intention, suggesting one’s level of education may impact intention to test.

The results of this study indicated participants who were male, high school educated, and smoked, showed greater interest in using genetic testing for the risk of cancer. As reported by the CDC ^[35], smoking was more common among male high school students. Considering the established link between smoking and lung cancer, high school educated males may have demonstrated greater interest in using genetic testing because they believed they were more likely to develop lung cancer. Program developers can apply these findings to create targeted programs that can educate the public about the benefits of genetic testing.

5. Conclusions

Overall, this study demonstrated that the public’s awareness about genetic testing for lung cancer risk is limited. Most participants believed lung cancer to be a severe condition and saw testing as beneficial. Those who perceived benefits were more likely to have higher intentions to use genetic testing, but in general, the overall intention to use genetic testing to detect the risk of lung cancer was low. This study shows the need for efforts in increasing awareness about genetic tests. The study also provides perceptions on the genetic test for the risk of lung cancer which can be used to promote the use for at-risk populations.

6. Limitations

There are several limitations of this study. First, it was a cross-sectional study focused on intention to use rather than actual behavior. Also, the study methods may have elicited participation and social desirability bias. Furthermore, the sample was drawn from three cities across the state of New Jersey, which drew a predominantly young (below 35yrs) female sample in the median income range with a high school or some college education. Considering the limitations, these findings could be generalized with caution. Since Jonassaint et al (2010) found geographic location to be a significant factor in awareness, future studies may examine distinctly different geographic regions.

Declaration

The study was approved by the Institutional Review Board at Long Island University, Brooklyn and all procedures comply with the current laws of United States of America. The authors also declare no conflict of interest.

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