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kontakt 20 (2018) e126–e133
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Original research article
Exogenous risk factors for colorectal cancer in people aged 50 years and older Zuzana Spáčilová *, Andrea Solgajová, Gabriela Vörösová, Dana Zrubcová Constantine the Philosopher University in Nitra, Faculty of Social Sciences and Health Care, Department of Nursing, Nitra, Slovak Republic
article info
abstract
Article history:
Colorectal cancer is a preventable disease caused by endogenous and external environmen-
Received 17 July 2017
tal factors. The study objective was to map the incidence of exogenous risk factors for
Received in revised form
colorectal cancer among the lay public in relation to age. The quantitative study was
18 September 2017
conducted by using the questionnaire ‘‘Colon Cancer’’, which was supplemented by self-
Accepted 27 November 2017
designed items. To process the obtained data, we used several mathematical and statistical
Available online 6 December 2017
methods found in STATISTICA and MS Excel. The sample consisted of 1715 respondents (males and females) from every region of Slovakia, including 1120 younger respondents (50–
Keywords:
59 years old) and 595 older respondents (60 years and older). They had no cancerous diseases
Colorectal cancer
in their medical history; and they had no healthcare education. We found a high incidence of
Age
some exogenous risk factors for colorectal cancer: 60.36% of the younger respondents and
Risk factors
75.12% of the older respondents were overweight and suffered from obesity; 47.32% of the younger respondents and 41.18% of the older respondents ate large amounts of red meat; 76.52% of the younger respondents and 73.61% of the older respondents did not eat the recommended daily allowance of vegetables; and 47.77% of the younger respondents and 57.65% of the older respondents did not do adequate physical activity. We found that there was a statistically significant relationship between age and BMI, red meat consumption, physical activity, and smoking ( p < 0.05). The frequency of consumption of vegetables and alcohol did not depend on the respondents' age. There is a high incidence of exogenous risk factors for colorectal cancer in the Slovak population. We recommend implementing preventive strategies against colorectal cancer in individuals, communities, and society. © 2017 Faculty of Health and Social Sciences of University of South Bohemia in České Budějovice. Published by Elsevier Sp. z o.o. All rights reserved.
* Author for correspondence: Constantine the Philosopher University in Nitra, Faculty of Social Sciences and Health Care, Department of Nursing, Kraskova 1, 949 74 Nitra, Slovak Republic. E-mail address:
[email protected] (Z. Spáčilová). https://doi.org/10.1016/j.kontakt.2017.11.005 1212-4117/© 2017 Faculty of Health and Social Sciences of University of South Bohemia in České Budějovice. Published by Elsevier Sp. z o.o. All rights reserved.
kontakt 20 (2018) e126–e133
Introduction Colorectal cancer is a multifactorial disease affecting the large intestine and rectum [1,2]. It is a malignant neoplasm that results from a malignant transformation of the cylindrical epithelium of the large intestine and rectum [3]. Nine of ten malignant colorectal tumours are preceded by a benign adenoma that is considered a precancerosis [4]. In 2015, according to the estimates of the International Agency for Research on Cancer (IARC), colorectal cancer was the third most commonly diagnosed cancer in men and the second in women worldwide [2]. According to the IARC estimates, in 2012 the Slovak Republic (SR) was among the countries with the highest incidence rates of malignant colorectal cancers worldwide [5,6]. The latest data on the incidence rates of malignant tumours in Slovakia show that malignant colorectal tumours in men are dominant. In women, the incidence of colorectal cancer comes in second place (after malignant breast tumours), but its incidence has been increasing [7]. The exact cause of colorectal cancer is not known; however, multiple risk factors are known. Based on the known data it has been estimated that colorectal cancer develops through a complex interaction between endogenous factors and external environmental factors [1,2,8,9]. The endogenous factors include genetic factors and predisposing factors. Regarding hereditary factors, there is an increased risk for colorectal cancer in people with hereditary nonpolyposis colon cancer, people with familial adenomatous polyposis, and people with hamartomatous polyps in the small and large intestine [1,10,11]. The predisposing factors include age (the disease is significantly more common in people older than 50 years of age), gender (the incidence of colorectal cancer is higher in men; rectal cancer prevails in men, colon cancer is more common in women), positive family or personal history, nonspecific inflammations of the colon (particularly ulcerous colitis, Crohn's disease), implantation of the ureters in the large intestine and rectum, radiotherapy applied in neoplastic processes in the minor pelvis, and the presence of Barrett's oesophagus [1,10–12]. Furthermore, the relationship between diabetes mellitus and an increased risk for colorectal cancer in men and women was found [13,14]. The exogenous etiologic factors of colorectal cancer include lifestyle factors, such as: food (its qualitative and quantitative composition), smoking, alcohol consumption, physical activity, and obesity [1,2,15]. The external environmental factors can have not only an aggressive or tumorigenic influence, but also a protective influence. In recent years, epidemiologic and experimental studies have proved a convincingly strong relationship between nutrition (unhealthy diet) and colorectal cancer. High fat intake (particularly animal fats), increased consumption of meat (particularly red meat and meat prepared by inappropriate technologies), higher caloric intake (often related to obesity, hyperglycaemia and hyperinsulinism), decreased dietary fibre intake and low micronutrient intake (vitamins and minerals) are considered critical factors that increase the incidence of colorectal cancer [1,2,15,16]. There is also an increased risk of colorectal cancer in smokers and alcohol consumers [1,2,8]. Furthermore, a lack of physical activity is one of the risk factors for colorectal carcinoma
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[1,15,16]. The protective factors include enough dietary fibre in the diet, calcium, vitamin D, acetylsalicylic acid, non-steroid antiflogistics, and a composition of the bacterial intestinal microflora [1,2]. In the epidemiology of colorectal cancer, the age factor is manifested very strongly as a basic (endogenous) risk factor. Up to 90% of all colorectal cancers have been diagnosed in the population older than 50 years of age [8,11,12]. Considering this figure, we decided to study the presence of risk factors in the most at-risk population, i.e. respondents aged 50 years and older. The study objective was to map the incidence of exogenous risk factors for colorectal cancer among the lay public in relation to age.
Material and methods We used a cross-sectional quantitative design for the study conducted on the basis of a questionnaire investigation. We used a questionnaire based on the items from the free-access test ‘‘Colon Cancer’’ at ‘‘Your Disease Risk’’, which was supplemented by self-designed items. Originally, ‘‘Your Disease Risk’’ was developed by the Harvard Centre for Cancer Prevention at Harvard University, as the Harvard Cancer Risk Index in 1997. It was a simple instrument used to find an estimated risk for cancer. This instrument was developed by epidemiologists, clinical oncologists and other experts from Harvard University who professionally focused on the issue of malignant tumours and their risk factors [17]. The Colon Cancer test is based on the scientific data, particularly on the proven relationships between a tumour onset and the risk factors. The questionnaire in our study consisted of 22 items from the Colon Cancer test that were divided into four areas: demographic data (categorization items: gender, education, residence, age), history (items related to personal, family and medication history), lifestyle (items related to diet, alcohol consumption, physical activity, and weight and height for calculation of the body mass index), and the history of colorectal cancer screening tests. The questionnaire was supplemented by two self-designed items related to lifestyle (items related to vegetable consumption and smoking). The questionnaires were distributed to respondents via student volunteers from the selected and addressed universities and secondary schools from each region in Slovakia. In each of the addressed schools there was a coordinator who explained the study objective and inclusion criteria to the students. Filling in the questionnaires was voluntary and anonymous. The data collection was conducted from June 2009 to March 2010. For our study purposes, we analysed the demographic data and the data related to the studied exogenous risk factors for colorectal cancer. We analysed the questionnaire items on lifestyle, specifically the items of weight (kg) and height (cm) for calculation of the Body Mass Index (BMI), and the items related to alcohol consumption, red meat consumption, vegetable consumption, smoking, and physical activity. We used descriptive and analytical statistics to process and analyse the data. The statistical analysis was conducted with the use of the algorithms found in the applications STATISTICA and MS Excel. To verify a hypothesis, we used the Chi2-test (a Chi-Square Test of
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Independence). Also, we stated p-values in hypotheses testing. The hypotheses were tested at the significance level p = 0.05. The sample for the questionnaire included the inhabitants of the towns and villages in the Slovak Republic. The sample consisted of 1715 respondents who met the inclusion criteria: ≥50 years of age; male and female; willingness to cooperate (to fill in the questionnaire). The exclusion criteria were: the presence of a tumour (except non-melanoma skin cancer) in the personal history; and healthcare education. The sample consisted of 694 (40.47%) men and 1021 (59.53%) women. The highest achieved education was: basic education in 171 (9.97%) respondents; vocational education in 549 (32.01%); secondary education in 743 (43.32%); and university education in 252 (14.69%) respondents. The sample included 869 (50.67%) respondents from towns and 846 (49.33%) respondents from villages. The respondents were from all regions in Slovakia; there were 243 (14.17%) respondents from the Trenčín Region, followed by 227 (13.24%) respondents from the Nitra Region and 216 (12.59%) respondents from the Košice Region. The fourth largest group included 211 (12.30%) respondents from the Trnava Region, followed by 207 (12.07%) respondents from the Banská Bystrica Region, 206 (12.01%) respondents from the Žilina Region, 204 (11.90%) respondents from the Bratislava Region, and 201 (11.72%) respondents from the Prešov Region. We divided the respondents into two age groups: younger (50–59 years of age) and older (60 years of age and older). In professional literature, we can find several types of periodisation of human life; most countries use the periodisation of human age suggested by the World Health Organisation (WHO). According to this, human life can be divided into the age groups lasting for 15 years. An age from 45 years to 59 years is, according to the WHO, considered middle age, and an age from 60 years is considered old age, including three periods (early old age, old age itself, and longevity) [18,19]. According to Čornaničová [20], a person older than 60 years of age can be considered a senior. Based on this division, the younger respondents in our study, from the point of view of periodisation of human life, were in the period of middle adulthood, and the older respondents were in the period of old age (senium). There were 1120 (65.31%) younger respondents and 595 (34.69%) older respondents. The youngest respondent was 50 years old and the oldest one was 95 years old (AM = 59, SD 7.85).
Results In the study, we studied the incidence of exogenous risk factors for colorectal cancer (BMI, alcohol consumption, red
meat consumption, vegetable consumption, smoking, and physical activity) related to respondents' age.
Relationship between BMI and age We assessed the incidence of overweight and obesity through the BMI; the category of ‘‘overweight’’ included 44.64% of the younger respondents and 48.40% of the older respondents. The category of ‘‘class 1 obesity’’ included 12.86% of the younger respondents and 20.00% of the older respondents; the category of ‘‘class 2 obesity’’ included 2.41% of the younger respondents and 5.71% of the older respondents; and the category of ‘‘class 3 obesity’’ included 0.45% of the younger respondents and 1.01% of the older respondents. After adding up the numbers of the respondents in the BMI categories from ‘‘overweight’’ to ‘‘class 3 obesity’’ in the individual age groups, we found that up to 60.36% of the younger and 75.12% of the older respondents had a BMI of 25 or more. We used the Chi2-test to verify the relationship between the respondents' BMI values and age. We found a statistically significant relationship between a BMI value and age, i.e. the respondents' BMI values statistically significantly increased with their age (Table 1).
Relationship between alcohol consumption and age More than a half of the respondents (61.07% of the younger and 59.16% of the older ones) did not consume alcohol on a typical day, or rather, 31.43% of the younger and 32.61% of the older respondents stated consuming one serving of alcohol daily (one serving was defined as a can of beer, a glass of wine or a shot of hard liquor). Consumption of two servings of alcohol was stated by 5.45% of the younger and 6.39% of the older respondents. Consumption of three or more servings of alcohol on a typical day was stated by 2.05% of the younger respondents and 1.85% of the older respondents. We used the Chi2-test to verify the relationship between the respondents' alcohol consumption and age at the 5% significance level ( p = 0.05). Table 2 shows the calculated value of p > 0.05; thus, there was no statistically significant relationship between the respondents' alcohol consumption and age.
Relationship between red meat consumption and age Table 3 shows that a consumption of three or more servings of red meat a week (one serving of meat was defined as approximately 110 g of meat or about the size of a deck of cards) was stated by the younger respondents more often (47.32% vs. 41.18%). We used the Chi2-test to verify the
Table 1 – BMI and age. Age
Younger Older
BMI Underweight
Normal weight
Overweight
Class 1 obesity
Class 2 obesity
Class 3 obesity
n (%)
n (%)
n (%)
n (%)
n (%)
n (%)
8 (0.71) 1 (0.17)
436 (38.93) 147 (24.71)
500 (44.64) 288 (48.40)
144 (12.86) 119 (20.00)
27 (2.41) 34 (5.71)
5 (0.45) 6 (1.01)
p – significance level.
Total
Chi2-test
p
1120 (100) 595 (100)
53.2910
0.05; thus, there was no statistically significant relationship between the respondents' vegetable consumption and age.
Relationship between smoking and age In the sample, there were more smokers among the younger respondents (31.16%) than among the older respondents (21.34%). We used the Chi2-test to test the dependence between the variables; p < 0.001 is significant at the 5% significance level ( p = 0.05). We found a statistically significant relationship between smoking and age; there were statistically significantly more smokers among the younger respondents (Table 5).
Relationship between physical activity and age In the area of physical activity, we asked the respondents if they walk (or do other moderate physical activities) for at least
30 min on most days or for at least three hours per week. Table 6 shows that positive answers were more frequent in the younger respondents (52.23%). We used the Chi2-test to test dependence between the variables. We found a statistically significant relationship between physical activity and age; there were statistically significantly more physically active younger respondents.
Discussion Brabcová et al. [21] state that the incidence of colorectal cancer is influenced by bad eating habits and way of life in 80% of cases. The study objective was to map the incidence of exogenous risk factors for colorectal cancer among the lay public in relation to age. The specific and influenceable risk factors for colorectal cancer include overweight and obesity that are characterised by an excessive amount of body fat. The obesity rate can be determined by the BMI. Individuals with high BMI values (overweight to obese) are at a higher risk of colon cancer [15,22– 24]. In the Slovak population, the percentage of the incidence of overweight to obese is high [25]. In our sample, the risk factor for colorectal cancer (BMI of 25 and more) was found in 60.36% of the younger and 75.12% of the older respondents; a statistically significant relationship between the BMI value and age was proved – the BMI values increased along with the respondents' age. Our findings are consistent with the results of the monitoring of risk factors in 2014 (in the health counselling centres of the Regional Public Health Authority of the SR), in which the incidence of overweight and obesity increased with age too. The highest number of persons with obesity was found in the clients older than 65 years of age [26].
Table 4 – Vegetable consumption and age. Response
Consumption of 3 or more servings of vegetables a day p – significance level.
Age
Younger Older
Yes
No
Total
n (%)
n (%)
n (%)
263 (23.48) 157 (26.39)
857 (76.52) 438 (73.61)
1120 (100) 595 (100)
Chi2-test
p
1.7725
0.1831
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Table 5 – Smoking and age. Response
Smoking
Age
Younger Older
2
Yes
No
n (%)
n (%)
Total Chi -test n (%)
349 (31.16) 127 (21.34)
771 (68.84) 468 (78.66)
1120 (100) 595 (100)
18.6726
p
