Awareness of Lung Cancer Symptoms and Risk Factors in General Population

Introduction: Lung cancer is often diagnosed in a late stage, which might be related to lack of risk factors and symptoms awareness. Aim of this study was to evaluate these factors. Methods: A survey was conducted to assess the awareness of lung cancer risk factors and symptoms. Kruskal-Wallis, Fisher and chi-square tests were used to compare the groups. Results: Altogether 403 participants (108 male; median age 29 (range 13 to 74) years; 98 smokers, 90 ex-smokers and 212 non-smokers) completed the survey (321 filled in online questionnaire, 82 were interviewed face-to-face). Three per cent of the respondents were unable to name any lung cancer risk factor, 36% named one and 61% named two or more. Smoking was mentioned most commonly, others far less often. When presented with a list of lung cancer risk factors, 99.7% of respondents recognised two or more; most commonly smoking (99%) and second-hand smoking (95%). Concerning symptoms, 17% were unable to name any, 21% named one and 62% named two or more. Prolonged cough was mentioned most often (59%), followed by dyspnea (45%) and chest pain (30%). When presented with a list, 99% of respondents recognised two or more symptoms; most often prolonged cough (86%), weakness (85%) and chest pain (82%). There were no statistical differences in lung cancer symptom, risk factor or prognosis awareness among smokers, ex-smokers and nonsmokers. There were some differences related to age, sex, education and type of used questionnaire. Conclusions: Awareness of lung cancer risks and symptoms is moderate in general population without major differences between smokers and non-smokers.


Introduction
Commission of the European Communities has identified cancer (including lung cancer) as one of the most frequent causes of death in Europe and called for European Union wide cooperation.The Commission Communication on Action against Cancer: European Partnership sets the goal to reduce cancer prevalence by 15% by 2020 [1].Estonia also has a National Cancer Strategy for 2007-2015, which states as one of the goals to reduce the occurrence of preventable malignant cancer cases.According to the document, this can be achieved by promoting healthy lifestyle and rising risk factor awareness [2].Research supports this claim, showing that more than half of the cancer cases could be avoided with modern knowledge [3].Lung cancer is one of the most common types of cancers worldwide [4] and also in Estonia, accounting for roughly 10% of all cancer cases [5].
Majority of lung cancer cases are diagnosed in a late stage, which might be at least partly related to the lack of lung cancer risk factors, symptoms and prognosis awareness.
Lung cancer is considered treatable only in early stages therefore early detection is also very important.Better symptom awareness is believed to aid early stage discovery [6].
Current study was conducted to evaluate lung cancer risk factors and symptoms awareness in general population.

Materials and Methods
To assess the lung cancer awareness of the general population a questionnaire was created by a senior investigator (TL).No previously validated questionnaire was available.Full questionnaire is provided as an attachment (see Appendix).
Study data were collected from December 2012 until April 2013.Majority of the participants were surveyed online, the link to the electronic questionnaire was posted on social media and on various discussion boards.The rest of the participants were interviewed face to face.For this purpose participants were recruited in various public spaces-stores, streets etc.All interviews were conducted by first author of the manuscript (HMH) and carried out strictly according to the questionnaire.Exactly the same questionnaire was used online.

Awareness of Risk Factors
The questionnaire included 3 questions with the aim of gauging risk factor awareness.First the participants were asked to recall lung cancer risk factors.Then they had to choose ones related to lung cancer from a given list of 8 most common risk factors.All the risk factors listed were connected to lung cancer.The third question asked the participant to assess the importance of smoking as a lung cancer risk factor.

Awareness of Symptoms
Two questions helped to identify awareness of lung cancer symptoms.First one asked the participants to recall symptoms related to lung cancer, second one provided a list of 10 most common symptoms and participants had to choose ones related to lung cancer.All symptoms listed were related to lung cancer.

Additional Questions
The questionnaire also included general questions about lung cancer.Participants were asked whether lung cancer occurs more often in men or women and whether it is treatable.Participants were also asked to provide their gender, age, education level and smoking habits.

Statistics
Kruskal-Wallis and Fisher's exact tests were used to find out factors associated with awareness.
No formal approval from ethical committee was obtained as no interventions were performed and no identifying data were collected from the study participants.

Results
A total of 403 people participated, 82 people were surveyed face to face on the street by one investigator and 321 study subjects filled in the questionnaire online.Participants' characteristics are listed in Table 1.
In this question age was connected to the outcome (p = 0.043).Older people recognised more risk factors.Gender (p = 0.417); education level (p = 0.092) and smoking habits did not affect the results (p = 0.958).
When asked about the role of smoking in developing lung cancer 342 respondents (84.9%, 95% CI 81.0% -88.2%) thought it had a significant effect.Forty-four people (10.9%, 95% CI 8.0% -4.4%) thought that it has an effect, but not a significant one.Ten (2.5%, 95% CI 1.2% -4.5%) people said maybe and 7 (1.7%, 95% CI 0.7% -3.5%) people thought that other risk factors had a bigger effect.No respondents thought that there was no link between smoking and lung cancer.
Statistically not significant, but clear trend was seen that none-smokers considered smoking to be more important risk factor than ex-smokers and current smokers (p = 0.057).Older patients believed more commonly that other causes than smoking are more important LC risk factors (p = 0.021).Education level (p = 0.843) and gender (p = 0.307) did not affect the results.
Number of symptoms recognised was not affected by the level of education (p = 0.108), age (p = 0.264), gender (p = 0.150) or smoking habits (p = 0.696) of the respondent.

Style of Questionnaire
The answers to some questions were affected by the way the questions were asked (face-to-face or online).Specifically questions 2 (p < 0.001), 4 (p < 0.001), 5 (p < 0.001) and 7 (p < 0.001) were affected.
In question 4, no people interviewed on the street were able to name 5 or more symptoms (14 people interviewed online were able to do so).Also more people on the street were unable to name any symptoms (34.1% (95% CI 24.0% -45.4%) compared to 12.5% (95% CI 9.1% -16.6%) online).
Out of people interviewed online 5.0% (95% CI 2.9% -8.0%) believed that lung cancer is incurable while none of the ones interviewed on the street agreed with this.Still most people in both groups believed that lung cancer is curable in early stages (89.4% (95% CI 85.5% -92.6%) online and 81.7% (95% CI 71.6% -89.4%) on the street).
There were some differences in terms of demographical characteristics of the two groups.While age distribution was similar in both groups (p = 0.903), there were differences in gender (p < 0.0001), education level (p = 0.0006) and smoking status (p = 0.013).

Discussion
Awareness of LC risks and symptoms is moderate in Estonian population.Similar or somewhat lower cancer risks and symptoms awareness findings have been published in previous studies analysing lung cancer in UK [7] or Canada [8], breast cancer [9] or cervical cancer [10].
Most important LC risk factor is smoking and that is also the most well known risk factor by study subjects, which may be due to the amount of campaigns focused on that topic.Other risk factors were poorly recognised.Surprisingly more people named family history or previous lung cancer history and air pollution more often as risk factor than second-hand smoking.However, when provided a list of risk factors, 95% of our study subjects recognised second-hand smoking as a LC risk factor compared to 67% from a previous French study [11].There are probably differences in risk factor awareness between different countries.Comparing our results with a previous study performed in UK [7], Estonians were able to name more symptoms, namely air pollution and family history or previous lung cancer.Variations between different countries might be explained by extent of anti-tobacco warnings and campaigns performed in respective countries [12].Knowledge about LC symptoms was also relatively low, but as lung cancer does not have very specific symptoms, the finding was quite predictable.However, the most often named symptoms-cough, chest pain and dyspnoea are the most common LC symptoms, which unfortunately in majority of cases indicate advanced stage cancer [13].Again, when comparing to study performed in UK [7], Estonians named more and also somewhat different symptoms.Shortness of breath, haemoptysis and chest pain were most commonly named in UK, other symptoms were named by less than 10% of respondents [7].In our study, six symptoms were named by more than 10% of respondents, including cough, chest pain, dyspnoea, fatigue, hoarseness and haemoptysis.
The participants were significantly better at recognising risk factors and symptoms from a given list.However this is not a good indication of awareness as respondents can simply guess.Very similar finding was demonstrated in previous lung, breast and cervical cancer studies [7] [8] [9] [10].
Smoking as a major lung cancer risk factor was expected to influence considerably people's beliefs and knowledge about LC.Out of all the participants in our study 24.8% were current smokers, which corresponds well to the 26% smoking rate in Estonia as stated by Eurobarometer [14].However, the smoking status influenced only study subjects' beliefs about role of smoking as a lung cancer risk factor.Not statistically significant, but a clear trend was seen that nonesmokers considered smoking to be more important risk factor than ex-smokers and current smokers (p = 0.057).Some previous studies conducted in other countries have shown connections between smoking status and awareness [9].Walker et al. analysed lung cancer risk factor awareness among persons with one or several risk factors [8].They demonstrated that current smokers, compared to previous or non-smokers, consider smoking and exposure to second-hand smoke or air pollution less important lung cancer risk factors [8].
Older people in our study thought less frequently that smoking is a risk factor of LC (p = 0.021).Fact that smoking causes several diseases including lung cancer is evident more than 50 years, however this knowledge is widely distributed only during last few decades.Therefore older people might still consider smoking as not so important risk factor of lung cancer.
In the future it is advisable to carry out more campaigns rising awareness of both symptoms and risk factors.More studies with bigger samples could help to identify possible focus groups for these campaigns.
One limitation of our study is that the study population was relatively young, with female predominance and more highly educated than population average.While answers to some questions were affected by age, gender or education level of the respondent, the data showed no significant overall impact of these factors.
The style of questionnaire used (online or face-to-face interview) affected the results of some questions.
In one previous study, similarly telephone and internet survey was used [8].
Authors did not provide data of results obtained either by phone or online survey and did not analyse the results separately.Another limitation of our study was that no power calculation was made before the study to compare online and face-to-face interview results.
Awareness of lung cancer risks and symptoms is moderate in general population without major differences between smokers and non-smokers, although smoking specifically is considered to be more important risk factor by non-smokers than smokers.After providing a list of answers, considerably more of lung cancer risk factors and symptoms are recognised by respondents.
Questioning environment somewhat influenced the answers and it should be taken into consideration when planning future studies.

Table 1 .
Demographic characteristics of study participants.

Table 2 .
Lung cancer risk factors recalled and recognised by study participants.

Table 3 .
Lung cancer symptoms recalled and recognised by study participants.