1. Background
Colorectal cancer (CRC) is the third most common cancer in men and the second in women (10.2% of the total cancer incidence in 2018) and is the fourth leading cause of cancer-related deaths in the world (1). Although CRC incidence and mortality rates have been declining in a number of the highest indexed human development index (HDI) countries but it is increasing in the Eastern Europe, Asia and South America (2, 3). According to the latest report of the International Agency for Research on Cancer (IARC), colorectal cancer is the fourth most common cancer in both sex and all ages in Iran (4). The latest data by the Iran National Cancer Registry (INCR) reported an annual number of 51000 cases of cancer with about 35000 cancer-related deaths in the country. In addition, the incidence rate of colorectal cancer was reported 7.9 in 100000 persons in 2018 and the 5-year survival rate was reported 43% - 49% in Iran (5). Available data indicated Iranians at a younger age are more affected than other population and about 43% of CRC patients are under 50 years old (6, 7). Some factors such as inflammatory bowel disease history (Crohn’s disease, ulcerative colitis), diabetes mellitus, environmental risk factors (including obesity, radiation, present, and past smoking habits), and high consumption of red meat have a major role in colorectal cancer diseases (8, 9). Physical activities apart from other environmental causes can play an important role in the development of colorectal cancer (10). First-degree relatives (FDR) of patients with colorectal cancers are a known risk factor for CRC so developing colorectal cancer among them is 2 to 3 fold higher than the normal population (11). Screening in FDRs is recommended from the age of 40 or 10 years before the age of youngest case in the family since the disease in FDR tends to develop about 10 years earlier than in the general population. Early diagnosis causes better survival in patients with early-stage CRC (12-14). One study in Iran indicated the consent rate of FDRs to participate in colorectal screening was 59%. Low educational level, low socioeconomic status, and restricted access to preventive health services were the related reasons to non-participating in colonoscopy screening test in FDRs (15). There were not extensive studies on the effect of kind of diet (intake of carbohydrate, fat, protein, fruit and vegetables), physical activity, and consent rate of a colonoscopy screening test in FDRs.
2. Objectives
The aim of this study was estimation compliance to undergo colonoscopy test in first- degree relatives and its relationship with FDRs lifestyle.
3. Methods
In this cross-sectional study, according to P = 60% (prevalence of participation in the colonoscopy screening test in FDRs) (7) and d = 0.09 (precision) with significant level α = 0.05, at least 114 persons were calculated. We decided to add 10 persons to the sample size in order to avoid the reduction in the number of missed cases during the follow-up process. Therefore, 124 FDRs randomly selected among archive of colorectal cancer patients’ information in one academic center, Tehran Iran in 2018. Inclusion criteria were FDRs with age range 35 - 75 years old without history of hereditary colorectal cancer. Exclusion criteria were who had colonoscopy or barium enema in the preceding 5 years and had inflammatory bowel diseases. They were all invited by phone to present in the gastroenterology department of colorectal cancer preventive clinic in order to consult about the prevention of colorectal cancer by colonoscopy screening test. They attended in the clinic and the preventive medicine specialist explained CRC risk factors and the ways of prevention through in-person counseling. In addition, they were recommended for participating in colonoscopy screening test at specified intervals. Each of FDRs was followed up after at least 3 months by telephone call. Participation rate in colonoscopy screening program was estimated. Next, the relationship between the tendency to participate with demographic information (age, sex, educational level), socioeconomic status (job, income, health insurance), symptoms of hypertension and diabetes, and lifestyle including body mass index (BMI), cigarette smoking (current or before), diet (carbohydrate, fat, protein, fruit, and vegetables), and physical activity (minutes per week) were assessed. Total information was self-reported. Informed consent was obtained from all participants. This study was approved by the ethical committee of Shahid Beheshti University of Medical Sciences, Tehran, Iran. For analyzing the descriptive statistics, mean (standard deviation) and number (percent) were used. Chi-square (Fisher exact) and independent t-tests (data were normally distributed) were applied for assessing the relationship between variables. Furthermore, multivariable logistic regression analysis with entering more significant (P ≤ 0.1) variables to predict the tendency of participation in colonoscopy screening was performed (odds ratio, 95% confidence interval). P values below 0.05 were considered significant in all tests.
4. Results
In this study among 114 FDRs who were consulted, 65 (57%) person undergone colonoscopy tests up to the time of evaluation or tended to undergo colonoscopy screening soon. The mean age of compliance and non-compliance group was 50.50 ± 7.89 and 53.73 ± 8.70 years, respectively. In the independent t-test analysis there was statistical association between age and tendency to participate in colonoscopy program (P = 0.04). In addition, in chi2 or Fisher’s exact test, there was significant association between monthly income and tendency to undergo colonoscopy (P < 0.001, OR = 2.1, 95% CI: 1.01 - 2.9) so 86.2% of the FDRs in the compliant group were in monthly income 20 million Rials (US dollar equal to 120000 Rials) and more. Furthermore, there was a significant relationship between physical activity and willingness to participate (P < 0.001, OR = 1.8, 95% CI: 1.03 - 2.4) in colonoscopy screening program. It means 86.2% of FDRs who tended to undergo colonoscopy test, had appropriate physical activity (equal or more 150 minutes per week). In the current survey a significant association found between kind of diet and willingness to undergo colonoscopy screening test (P = 0.02, OR = 2.5, 95% CI: 1.9 - 3.8). Generally, 90.8% of FDRs had normal diet (normal intake of carbohydrate, fat, protein, fruit and vegetables) (Table 1). In multivariable logistic regression, age < 50 years old (P = 0.01, OR = 1.08, 95% CI: 1.01 - 1.8), higher income (equal and more than 20 million Rials) (P < 0.001, OR = 2.5, 95%CI: 1.8 - 11), appropriate physical activity (≥ 150 minutes per week) (P < 0.001, OR = 5.2, 95% CI: 4.6 - 17.5), and normal diet (intake of carbohydrate, fat, protein, fruit and vegetables) (P = 0.006, OR = 3.02, 95% CI: 2.9 - 6.6) were the predictor factors of participation in colonoscopy screening program (Table 2).
Table 1.
Relationship Between Characteristics of FDRs and Compliance to Their Participate in Colonoscopy Screening Testa
| Variables | Yes, 65 (57%) | No, 49 (43%) | P Value | OR (95% CI) |
|---|---|---|---|---|
| Age | 50.50 ± 7.89 | 53.73 ± 8.70 | 0.04b | |
| Sex | 0.2 | 0.5 (0.2 - 1.2) | ||
| Female | 33 (50.8) | 31 (63.3) | ||
| Male | 32 (49.2) | 18 (36.7) | ||
| BMI | 26.48 ± 3.67 | 28.08 ± 7.62 | 0.1 | 1.2 (0.4 - 2.3) |
| Marital status | 0.6 | 1.3 (0.4 - 3.8) | ||
| Single | 10 (15.4) | 6 (12.2) | ||
| Married | 55 (84.6) | 43 (87.8) | ||
| Ethnicity | 0.9 | 1.04 (0.4 - 2.3) | ||
| Fars | 47 (72.3) | 35 (71.4) | ||
| Non-Fars | 18 (27.7) | 14 (28.6) | ||
| Educational level | 0.06 | 0.3 (0.1 - 1.0.9) | ||
| Non academic | 48 (73.8) | 43 (87.8) | ||
| College/university | 17 (26.2) | 6 (12.2) | ||
| Job | 0.7 | 0.8 (0.3 - 1.9) | ||
| Employed | 43 (66.2) | 34 (69.4) | ||
| jobless | 22 (33.8) | 15 (30.6) | ||
| Monthly income | < 0.001b | 2.1 (1.01 - 2.9) | ||
| < 20000000 Rials | 9 (13.8) | 42 (85.7) | ||
| ≥ 20000000 Rials | 56 (86.2) | 7 (14.3) | ||
| Health insurance | 0.6 | 0.7 (0.2 - 2.4) | ||
| Yes | 59 (90.8) | 43 (87.8) | ||
| No | 6 (9.2) | 6 (12.2) | ||
| HTN | 0.3 | 0.6 (0.2 - 1.8) | ||
| Yes | 7 (10.8) | 8 (16.3) | ||
| No | 58 (89.2) | 41 (83.7) | ||
| DM | 0.2 | 0.5 (0.16 - 2) | ||
| Yes | 6 (9.2) | 8 (16.3) | ||
| No | 59 (90.8) | 41 (83.7) | ||
| Cigarette smoking | 0.8 | 1.09 (0.3 - 3.1) | ||
| Yes | 10 (15.4) | 7 (14.3) | ||
| No | 55 (84.6) | 42 (85.7) | ||
| Physical activity | < 0.001b | 1.8 (1.03 - 2.4) | ||
| Negative or low (< 150 minutes weekly) | 9 (13.8) | 41 (83.7) | ||
| Appropriate (≥ 150 minutes weekly) | 56 (86.2) | 8 (16.3) | ||
| Diet (carbohydrate, fat, protein) | 0.02b | 2.5 (1.9 - 3.87) | ||
| Low/normal | 49 (90.8) | 35 (71.4) | ||
| High | 16 (9.2) | 14 (28.6) |
Abbreviations: BMI, body mass index; DM, diabetes; HTN, hypertension.
aQualitative and quantitative data analysis were reported by No. (%) and mean ± standard deviation (SD), respectively. For the qualitative and quantitative analysis student t-test and chi2 test were applied.
bShow level of significance.
Table 2.
The Prediction of Compliance to Participate in Colonoscopy Screening Test in FDRs in Multivariable Logistic Regression
| Variables | OR (95%CI) | P Value |
|---|---|---|
| Age, y | 0.01a | |
| < 50 | 1.08 (1.01 - 1.8) | |
| ≥ 50 (reference) | ||
| BMI | 0.4 | |
| 18.5 - 24.9 (normal) | 0.8 (0.48 - 2.4) | |
| ≥ 25 (overweight/obesity) | ||
| Monthly income | < 0.001a | |
| ≥ 20000000 Rials | 2.5 (1.8 - 11) | |
| < 20000000 Rials (reference) | ||
| Physical activity | < 0.001a | |
| Appropriate (≥ 150 minutes per week) | 5.2 (4.62 - 17.5) | |
| Negative or low (< 150 minutes per week) | ||
| Diet (intake of carbohydrate, fat, protein and fruit/vegetables) | 0.006a | |
| Normal | 3.02 (2.9 - 6.6) | |
| High |
aLevel of significance
5. Discussion
In the present study, 57% of first-degree relatives underwent colonoscopy screening test or they were willing to do it soon. The mean age of 2 groups compliance and non-compliance of colonoscopy screening test was 50.50 ± 7.89 and 53.73 ± 8.70 years, respectively and there was a significant difference between groups (P = 0.04). Accordingly who were under 50 years old were associated with more willingness to undergo colonoscopy test (P = 0.01, OR = 1.08, 95%CI: 1.01 - 1.8). Based on the latest American Cancer Society Guideline, colorectal cancer screening is recommended to begin at a younger age for those who have close relatives with patients with colon cancer. For example, a person whose parents or siblings have colorectal cancer should undergo a periodic colonoscopy screening from the age of 40 or 10 years earlier than affected the patient in the family, and every 3 - 5 years it should be repeated (16). Courtney et al. in a population-based study in Australia in 2013 indicated 47% of FDRs were screened according to the Australian guideline recommendation (colonoscopy screening every 5 years) (17). In the Western countries, the uptake of colonoscopy among individuals with a family history of CRC is low (28% - 42%) (18-20). Armelao et al. in a survey in 2010 in Italy showed predictors of colonoscopy uptake were FDR with age above 60 years old [odds ratio (OR): 2.50, 95%CI: 1.72 - 3.62], and living in a rural area (OR: 1.64, 95%CI: 1.12 - 2.44) (21). In our survey monthly income equal or more than 20000000 Rials was a predictor of adherence to colonoscopy screening which is similar to a study carried out by Chouhdari et al. in 2016 (15). We did not find any association between compliance of FDR in colonoscopy screening test, background diseases, and cigarette smoking. In another study by Cho et al. in 2015, they indicated longer duration and more mean amount of alcohol consumption in men were associated with elevated risk of colorectal cancer (HR: 1.93 [1.17 - 3.18] for more than 30 years of consumption compared to non-drinkers; HR: 2.24 [1.31 - 3.84] for ≥ 30 g/d). Cigarette smoking was a non-significantly elevated risk of colorectal cancer in men. In their study, there was no apparent association between alcohol consumption or cigarette smoking and colorectal cancer risk among women (16). In the study by Courtney et al., adherence to colonoscopy screening was significantly more likely to occur for male FDRs and those with a higher level of education (17). Physical inactivity and excess body weight are considered as two modifiable and related to other risk factors, they are reported to account for about a 4th to a 3rd of colorectal cancers (22). Combined lifestyle factors are associated with a lower incidence of CRC in European populations characterized by western lifestyles (23). A sedentary lifestyle is attributed to influence changes in hormone and growth factor levels, increased fat in organs and impaired immune system function and it probably promoting the development of cancer (24). In one study in Egypt in 2010, the history of pesticide exposure and more frequent eating food directly from farms were significantly associated with a higher risk of colorectal carcinoma [odds ratio: 2.6, 95% confidence interval: 1.1 - 5.9; odds ratio: 4.6, 95% confidence interval: 1.5 - 14.6, respectively] (25). In one study in Iran, there was no difference between BMI and willingness to undergo colonoscopy in FDRs (P = 0.1) (7). In this research, appropriate physical activity (≥ 150 minutes weekly) (P < 0.001, OR: 5.2, 95%CI: 4.6 - 17.5) and normal diet (intake of carbohydrate, fat, protein, fruit and vegetables) (P = 0.006, OR: 3.02, 95%CI: 2.9 - 6.6) were the predictor factors to compliance the FDRs for participation in colonoscopy screening program. In the other study by Park et al. in 2005, dietary fiber intake was inversely associated with the risk of colorectal cancer in age-adjusted analyses (26).
5.1. Strengths and Limitation of the Study
We did not find any study for assessing the relationship between the lifestyle of relatives of patients with colorectal cancer and their willingness to participate in colonoscopy screening, therefore, this study can be considered as anew research in this field. In the present study, 10 FDRs did not present in the prevention clinic to be consulted by physicians. Accordingly, we were not able to analyze their characteristics. All information in the current survey was a self-report, so information bias may have occurred.
