Background:
Several studies had been conducted on the association between blood group ABO and the risk of gastrointestinal malignancies, such as gastric and pancreatic cancer. Studies have also been conducted on the risk of obesity with colorectal carcinoma (CRC). It is unclear whether there is an association between blood group ABO and CRC and which group is more affected.
Aim:
The aim of this study was to show an association between the ABO blood group, Rh factor, and obesity with CRC.
Patients and Methods:
One hundred and two patients with CRC were included in our case–control study. Blood group, Rh factor, and BMI were estimated and compared with a control group of 180 Iraqis who came to the Endoscopy Department of Al-Kindy Teaching Hospital for preoperative control colonoscopy between January 2016 and January 2019.
Results:
The overall distributions of ABO and Rh factor were comparable between patients (41.17% A+, 5.88% A−, 6.86% B+, 2.94 B−, 1.96% AB+, 1.96% AB−, 37.25% O+, and 1.96% O−) and controls (26.66% A+, 1.11% A−, 20% B+, 1.11 B−, 13.3% AB+, 1.11% AB−, 34.44% O+, and 2.22% O−). Statistically, there were significant differences between patients with CRC and control subjects in terms of their blood groups. The A+ group was found in 42 cases (41.17%), followed by O+ in 38 cases (37.25%). Their BMI ranged from 18.5 to 40 kg/m2. Overweight patients were more common in 46 cases (45%) followed by obesity class І 32 cases (32.37%) with a P-value of 0.00016. Sixty-two of the patients with CRC (60.78%) were male and 40 cases (39.21%) were female. Their ages ranged from 30 to 79 years with a mean age of 55.49 years. CRC 37 cases occurred in the age group of 60–69 years (36.27).
Conclusion:
In this study, a statistically significant association was found between the occurrence of CRC and patients with blood group A+, O+, overweight, and obesity class І.
Keywords: case–control study, colorectal carcinoma, obesity, general surgery, B group and Rh factor
Introduction
Highlights
Correlation between blood group and Rh with colorectal carcinoma (CRC) had been studied many years previously, and the relation with gastrointestinal tract was among these studies.
Many studies are done to show the risk of obesity for developing CRC.
There was a statistically significant association between the occurrence of CRC and blood group A+, O+, overweight, and class І obesity patients.
Male sex with an age group between 60 and 69 years with a median age of 55.49 showed a significant correlation with CRC.
Screening for CRC should be done especially among risk groups to be detected earlier and managed better than those with late diagnosis.
Cancer is a major cause of great psychosocial and economic burden worldwide. Annually, about 1.23 million people develop CRC, which is considered the most common cancer (9.7% of all cancers), and 8% (608 000 cases) died from CRC, making it the fourth leading cause of death among various cancers 1.
The distribution of cases varies widely worldwide, as shown by epidemiological data, according to which about 60% of cases of CRC occur in developed countries (2% per year), while in developing countries the incidence of cases of CRC increases annually, with the proportion of patients aged 40 years or less being 2–8% in Western countries, whereas it is ∼15–35% in the Middle East region1, and the incidence rate is lower in women than in men, with female sex being a favorable prognostic factor compared with male sex2.
There are three different risk groups for CRC, namely familial adenomatous polyposis, hereditary nonpolyposis colon cancer syndrome (Lynch syndrome), and genetic mutations leading to sporadic colon cancer3. The exact cause is unclear, but many factors are involved, including environmental and genetic factors. About 24% of cases with CRC are due to genetic factors, while 75% are sporadic and 1% occur in patients with preexisting inflammatory bowel disease4. Those who migrate from a low-incidence area to a high-incidence area of CRC may be susceptible to developing CRC, which may be related to red meat consumption and low physical activity2.
Environmental factors also include dietary factors such as fiber deficiency, high-fat diet, and mucosal exposure to high levels of bile acids due to impaired enterohepatic circulation, which leads to the formation of carcinogens from the breakdown of bile salts, while the previous cholecystectomy is not a risk for the development of CRC4.
Regarding genetic factors, there are several genes, including tumor suppressor genes (e.g. APC, p53), oncogenes (e.g. Ras), and mismatch repair genes (e.g. hMSH2 and hMLH1) that are responsible for the development of hereditary CRC4. In this study, two factors are discussed with their relationship to the development of CRC, these factors are the ABO blood group, and the Rh factor and the other is obesity and as follows: Actually, the first human genetic markers are antigens of the ABO system, although they are a chemical component on the erythrocyte membrane, they show the expression on a variety of epithelial cells, including the mucosa of the gastrointestinal tract, which has been the main cause of observational studies on a correlation between ABO blood group, Rh with tumor5.
Among the first studies, Aird et al. 6 reported a correlation between ABO Rh factor and gastric carcinoma in 1953, and recently a significant correlation with pancreatic tumors was also found7. In addition, many studies showed a correlation between ABO antigen expression and CRC5.
obesity, about one billion people worldwide now suffer from obesity, which is considered one of the strongest factors affecting many health conditions, including some cancers.
Many epidemiological studies have identified high BMI as an independent risk factor for CRC, with some of these studies in Western countries showing a significant association between BMI and risk for CRC8.
Aim
The present study aims to investigate the relationship between ABO and rhesus blood group, obesity, age, and sex in patients affected by CRC and attending Al-Kindy Teaching Hospital.
Patients and methods
During the period from January 2016 to January 2019, a case–control study was conducted at Al-Kindy Teaching Hospital on patients who visited the consultation of the Department of General Surgery and GIT with signs and symptoms suggestive of CRC. One hundred and two patients with approved CRC were included in our study and compared with a control group of 180 Iraqis who visited the Endoscopy Department for screening purposes.
The age and sex of the patients were recorded, the necessary history and clinical examination were performed, and a laboratory test was requested.
The hemagglutination method was used to determine the blood group and Rh factor of the patients and the control group.
The body weight and height of each patient were measured using an electronic scale with an associated height measurement scale (SECA). BMI was calculated using the BMI formula: BMI=weight in kg/height in meters squared. BMI was divided into five groups (18.5–24.9 kg/m2 normal, 25–29.9 kg/m2 overweight, 30–34.9 kg/m2 class І obese, 35–35.9 kg/m2 class ІІ obese, ≥40 kg/m2 class ІІІ obese) Colonoscopy was performed with an Olympus colonoscopy, a Lucera CLV-260, and the diagnosis CRC was confirmed by histopathological examination.
Patients with another history of cancer, patients with chronic diseases such as hypertension, and diabetes mellitus, patients with bowel obstruction due to tumors and athletes were excluded from the study.
The study registered in clinicaltrials.gov: NCT05520385 and also in researchregistry.com: UIN researchregistry8525.
Ethical consideration
The proposal for the study was discussed and approved by the scientific and ethical committee of the Iraqi surgical authority.
The agreement of the health authority in Al-Kindy Teaching Hospital was approved before collecting data.
Written consent was taken from each patient after an explanation of the aim of the study and the collected data will be anonymous and will not be used but for research purposes.
Statistical analysis
The collected data were refined and introduced into a Microsoft SPSS sheet and loaded into SPSS, V24 for statistical analysis.
Descriptive data were presented using frequency distribution tables including the number of cases and control and graphs, while deferential status was displayed. The chi-square method was calculated for all variables and a P-value of less than 0.05 was considered significant.
STROCSS criteria
The study has been reported in line with the STROCSS criteria25.
Results
One hundred and two patients were included in our study 62 of them (60.78%) were males and 40 (39.21%) were females. Their age ranged between 30 and 79 years old with a mean age of 55.49. Their BMI ranged between 18.5 and 40 kg/m2. Their blood group Rh was highest in A+ in 42 cases (41.17%) followed by O+ in 38 cases (37.25%) the number of patients having other blood groups were 6, 7, 3, 2, 2, 2 with 5.88%, 6.86%, 2.94%, 1.96%, 1.96%, 1.96% for A−, B+, B−, AB+, AB−, O−, respectively. as shown in Table 1.
Table 1.
ABO and Rh among patients and control
| n (%) | ||||
|---|---|---|---|---|
| Blood group | Total | Colorectal carcinoma (N=102 cases) | Control group (N=180) | P |
| A+ | 90 | 42 (41.17) | 48 (26.66) | 0.00049 |
| A− | 8 | 6 (5.88) | 2 (1.11) | |
| B+ | 43 | 7 (6.86) | 36 (20) | |
| B− | 5 | 3 (2.94) | 2 (1.11) | |
| AB+ | 26 | 2 (1.96) | 24 (13.3) | |
| AB− | 4 | 2 (1.96) | 2 (1.11) | |
| O+ | 100 | 38 (37.25) | 62 (34.44) | |
| O− | 6 | 2 (1.96) | 4 (2.22) | |
The Peak incidence of patients with CRC occurred in patients with blood group A+ 42 cases ( 41.17%) followed by blood group O+ 38 cases ( 34.44%) which were marginally significant, with a P-value of 0.00049. The results for other blood groups with a low percentage.
Forty-six patients were overweight (45%) followed by class І obesity 32 cases (32.37%), while the other group of patients were 20 (19.6%), 4 (3.92%) patients under normal BMI group, and class ІІ obesity respectively, as shown in Table 2.
Table 2.
BMI among patients and control
| n (%) | ||||
|---|---|---|---|---|
| BMI | Total | Colorectal carcinoma (N=102 cases) | Control group (N=180) | P |
| Normal | 102 | 20 (19.6) | 82 (45.55) | 0.00016 |
| Overweight | 96 | 46 (45) | 50 (27.77) | |
| Class І obesity | 72 | 32 (31.37) | 40 (22.22) | |
| Class ІІ obesity | 12 | 4 (3.92) | 8 (4.44) | |
| Class ІІІ obesity | 0 | 0 (0) | 0 (0) | |
Regarding BMI of patients with CRC, there was a significant difference between cases and controls, the association was most significant in an overweight group (25–29.9 kg/m2), 46 cases (45%) followed by class І (30–34.9 kg/m2), 32 cases (32.37%) with P-value of 0.00016.
CRC was highest in incidence in males as shown in Table 3. CRC occurred in 37 cases in the age group of 60–69 years old (36.27%), as shown in Table 4.
Table 3.
Sex distribution among cases and control
| n (%) | ||||
|---|---|---|---|---|
| Sex | Total | Colorectal carcinoma (N=102 cases) | Control group (N=180) | P |
| Male | 144 | 62 (60.78) | 82 (45.55) | 0.013 |
| Female | 138 | 40 (39.21) | 98 (54.44) | |
Table 4.
Age distribution among patients and control
| n (%) | ||||
|---|---|---|---|---|
| Age group (years) | Total | Colorectal carcinoma (N=102 cases) | Control group (N=180) | P |
| 30–39 | 25 | 11 (10.78) | 14 (7.77) | 0.00001 |
| 40–49 | 77 | 17 (16.66) | 60 (33.33) | |
| 50–59 | 78 | 18 (17.64) | 60 (33.33) | |
| 60–69 | 55 | 37 (36.27) | 18 (10) | |
| 70–79 | 47 | 19 (18.62) | 28 (15.55) | |
The range of age distribution for patients with CRC was from 30 to 79 years old, CRC was mainly in the age group more than 60 years old (60–69 years), 37 cases (36.27%) followed by the age group (70–79 years), 19 cases (18.62%). P-value of 0.00001 which is highly significant.
Regarding sex, there was a significant difference between cases and control. Most cases of CRC were male patients 62 patients (60.78%). The P-value was 0.013.
Discussion
This study is done to define the correlation between ABO and Rh groups, BMI, age, and sex with CRC.
A significant association between non-O blood groups with CRC was shown in a study done in Turkey between 2004 and 2011on 1620 patients with CRC in comparison with 3 022 883 healthy people as a control group from the Turkish Red Crescent, blood group and Rh factor was checked, between patients and controls the results showed statistically significant difference concerning for to O versus non-O blood group (P=0.033), while for blood group A versus non-A, the difference was marginally significant with (P=0.052)5.
A total of 18 244 Chinese men from Shanghai enrolled in 1986 in a prospective cohort study during the 25 years of follow-up, among them, 3973 men developed different types of cancer with 624 cases developing CRCs, the result showed a strong association between blood group A+ and CRC9.
Another study done in Ankara, Turkey included 486 patients with CRC and the most frequent location for the tumor was the rectum (n=203) followed by the sigmoid colon (n=138) and the result of blood group and Rh antigen subgroups analysis for patients showed that 253 patients (52.1%) were with blood group A and 370 patients (76.1%) were Rh positive, So the incidence of CRC was significantly higher among patients with blood group A+10.
Kashfi and colleagues thought that the ABO blood group and Rh factor were among the genetic factors that can be associated with CRC, So his study was for the correlation between blood group and CRC by enrolling the patients with CRC received in Namazi Hospital from 2002 to 2011. The highest frequencies in his study were among 223 patients with CRC who had blood group O+ (48.7%), and Rh+ (90.4%), So he concluded a significant correlation between blood group O+ and CRC11.
In Taiwan, follow-up for 27 years was done in a study involving 3180 men and 3124 women, their ages were ranging from 20 to 65 years, the data showed a significant correlation between the ABO blood group and risk of developing cancer and the result was men with blood group AB are more liable to develop gastrointestinal cancer, while the risk in women involving those with blood group A5.
Analyzed eight studies done in research about the correlation between CRC and blood groups by taking 6931 patients affected by cancer, they observed a decreasing risk of CRC in those people who had blood group O (odds ratio=0.89; 95% CI: 0.81–0.96) and high heterogeneity was found among studies (A vs. non-A, P=0.14; B vs. non-B, P=0.003; O vs. non-O, P=0.02; AB vs. non-AB, P=0.09)12.
In another study, among 104 885 persons enrolled in the study (76 408 females and 28 477 males) in Boston, 1025 CRC cases were documented in the study after a mean follow-up of 9.8 years. In two large prospective cohorts, there was no consistent correlation between the blood group and the risk of CRC but regarding blood group B there was a borderline significant correlation with the overall risk of CRC without a clear explanation of the biological mechanism for the differential association of group B compared with group A antigen with cancer. So, they concluded that these findings related to blood group B are likely due to chance13.
As a result of another study done in the USA, there was no clear correlation between ABO and the risk of CRC14.
From all of the above, we can see that there were many types of research on this topic some found a clear definite association, and others deny this association. Our study shows a significant association between blood group Rh A+ and O+ with CRC as in Table 1.
The studies that deny the relation between ABO and Rh blood type with CRC may be explained by the presence of different factors like the number of patients and distribution of blood groups in the region of study.
Now we will discuss obesity which can be defined as an imbalance between energy intake, and expenditure and assimilates environmental and genetic factors in the previous two or three decades the incidence of CRC increased dramatically with concern the (westernization) worldwide obesity phenomenon17.
Many studies done to evaluate any relation between CRC and obesity among them the study done in Japan that observed those with BMI ≥25 kg/m2 comprising 23.3% for male patients and 25.2% for female patients from data collected for 300 000 subjects. Those with BMI of 27–29.9 kg/m2, ≥30 kg/m2 had a significant association with CRC, while for those who had BMI ≤25 kg/m2, results were not significant8.
In Norway, height and weight were measured for two million males and females aged 20–74 years old during the period from 1963 to 2001 involved in the study. During follow-up, 47 117 CRC cases were registered, and the result showed that colon cancer risk was almost 50% high in an obese patient with BMI ≥30 kg/m2 18.
The data collected in the USA from 30 prospective studies worldwide showed about 30% increased risk of colon cancer for every 5-U increase in BMI in men, while a 12% in women, collected studies that involved 22 546 cases of men with CRC from 24 studies and (22 231 cases) women with CRC from 21 studies. With concern for the risk of proximal colon cancer in men, BMI was statistically significantly positive in both sexes for distal colon cancer. Although observation was done for the correlation between BMI and risk of colon cancer among studies had been done in both North America and Europe, the estimation of risk, in summary, was higher in North American studies (P-value was 0.01 for differences among men, while P-value was 0.004 for differences among women). The association between increased BMI and colon cancer risk also had been found among studies conducted in Asia, but only in men, the correlation was statistically significant19.
The studies on BMI as a risk factor for rectal cancer involved (13 830 cases) of men from 15 studies and (8878 cases) of women from 13 studies. Overall the results were showing that BMI was statistically significantly positive about the risk of rectal cancer in men (12% increase in risk for every 5 U higher BMI) but women did not like that. Among men, the correlation between BMI and risk of rectal carcinoma was similar in the studies carried out in Europe and Asia, while among studies conducted in North America, there was a statistically significant positive correlation between BMI and risk of rectal carcinoma among women, but not among studies conducted in Europe or Asia (P=0.02) that showed the difference in the association between geographic regions19.
Obesity has a direct and independent, relationship with CRC in a meta-analysis study, in which information on 70 000 patients with CRC had been included. Depending on these data, individuals who have a BMI of 30 kg/m2 have a 20% greater risk to develop CRC in comparison with those considered to be of normal weight (BMI <25 kg/m2). For every 2 kg/m2 increase in BMI, the risk to develop CRC increased by 7%20.
In 2002 the risk of developing CRC with concerning to increased body size was positive in the epidemiological data that was collected from several studies conducted in the USA, risks were elevated in men and women but were stronger for men than women. Of the eight case–control studies done for a relationship between BMI and CRC published to date, all showed relative risks greater than one for overweight or obese individuals with BMI (>25 kg/m2) and (>30 kg/m2), respectively compared with normal weight individuals (BMI 18.5–25 kg/m2) apart from two studies, one of them found an inverse correlation between BMI and CRC risk but among females patients and the other one showed no correlation. In contrast, the result was the same for the 10 prospective cohort studies, all reported a positive correlation between BMI and CRC17.
The collected data between 1986 and 1992 for the study done in the USA, the results showed an inverse association between physical activity and risk for developing CRC, while height and obesity, particularly abdominal adiposity, were associated with an increased risk of developing CRC21.
But another study conducted in Burgundy, France showed conversely no significant relation, where groups of case–control studies involving much information besides BMI, did not find any association for BMI with CRC. They thought that the cause may be due to recent weight loss associated with cancer even when CRC is rarely a wasting disease and they did not find any influence of BMI, even in patients with Dukes A or B tumors22.
In our study, there is an association between CRC and overweight patients (BMI 25–29.9 kg/m2) and class І obesity (BMI 30–34.9 kg/m2), respectively as in Table 2.
In contrast, our study shows a significant association between the male sex and CRC in the age group between 60 and 69 years with a median age of 55.49 as shown in Tables 3 and 4, respectively and this coincides with many studies, for example, the study done in Turkey, the median age was 62 years (range: 17–97 years), 58.1% were male in the study which included 1620 patients with CRC5.
Also, another study that involved 419 patients with CRC in Tehran, Iran found the mean age of males was 53.73 years and that of females was 51.18 years (P=0.7)15.
As regards the relation between sex and the development of CRC, the study done in Turkey taking 1620 patients, the result was 58.1% positive in males5.
Data from a total number of 419 patients were collected, in Iran. The result was 403 positive cases of 419 patients with adenocarcinoma (96.2%). There were 211 male (52.4%) and 192 female (47.6%) patients15.
In Japan, the study included 341 384 people (157 927 males and 183 457 females) with 4979 incident CRC cases (among them 3055 males, while females were 1924) during 3 765 498 person-years of follow-up (average follow-up: 11.0 years)8.
Conclusion
Blood group A+ and O+ patients are more prone to develop CRC than the others in our hospital. Overweight patients and those under class І obesity have a higher risk of developing CRC in our hospital. Male sex with age between 60 and 69 years old carries a high risk to develop CRC.
Recommendation
Patients who have signs and symptoms that may be related to CRC and who have blood group A+ or O+, those who are overweight, class І obesity, and especially male sex with age between 60 and 69 years old should be screened frequently for CRC. Those people with risk factors in our study like obesity should be advised to reduce weight.
Ethical approval
The proposal of the study was discussed and approved by the scientific and ethical committee of Iraqi Board of Surgery. The agreement of Health Authority in Al-Kindy Teaching Hospital was approved before collecting data.
Consent
Written consent was taken from each patient after an explanation of the aim of the study and the collected data will be anonymous and will not be used but for research purposes.
Sources of funding
We have no funding sources.
Author contribution
S.H.A.: data collection, data analysis, writing the paper, completion of the article. R.M.H.: study design, data collection, interpretation. L.N.H.: study concept and data interpretation.
Conflicts of interest disclosure
The authors declare that they have no financial conflict of interest with regard to the content of this report.
Research registration unique identifying number (UIN)
Name of the registry: Safaa Hadi Abdulsattar Alshihmani
Unique identifying number or registration ID: clinicaltrials.gov NCT05520385 – researchregistry.com UIN researchregistry8525
Hyperlink to your specific registration (must be publicly accessible and will be checked): https://clinicaltrials.gov/ct2/show/NCT05520385 https://www.researchregistry.com/register-now#user-researchregistry/
Guarantor
None.
Provenance and peer review
Not commissioned, externally peer-reviewed.
Footnotes
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
Published online 5 April 2023
Contributor Information
Safaa H. Abdulsattar, Email: safahadi82@yahoo.com.
Riyadh M. Hasan, Email: Riyadhmoh57@gmail.com.
Laith N. Hindoush, Email: safahadi2017@gmail.com.
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