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International Journal of Medical Laboratory
Shahid Sadoughi University of Medical Sciences
Fri, Apr 26, 2024
[Archive]
Volume 10, Issue 1 (February 2023)
IJML 2023, 10(1): 1-6 |
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Bashiri H, Madani M, Asgari L, Bozorgomid A. Characteristics of Diminutive Colorectal Polyps in Patients Undergoing Colonoscopy in an Educational, Therapeutic Hospital in Western Iran. IJML 2023; 10 (1) :1-6
URL: http://ijml.ssu.ac.ir/article-1-438-en.html
URL: http://ijml.ssu.ac.ir/article-1-438-en.html
Infectious Diseases Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Table 2. Demographic details and anatomical locations of polyps in adenomatous and non- adenomatous polyps
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Introduction
Colorectal polyps are lesions that grow on the surface of the intestinal mucosa. They can be categorized based on their size as diminutive (≤ 5 mm), small (6-9 mm), sub-centimeter (< 10 mm), or large (≥ 10 mm). Based on the presence or absence of dysplastic features, colorectal polyps are categorized into non-neoplastic and neoplastic (adenomas) [1]. Adenomas display a spectrum of dysplasia ranging from high grade to low grade. Over the past few years, much research has shown that most colorectal cancers develop from pre-existing adenomatous polyps [2]. Therefore, early detection and removal of adenomatous polyps provide an opportunity to prevent colorectal cancer (CRC).
CRC is usually an adenocarcinoma that occurs in the colon or rectum. It is the third most common cancer in the Iranian population, and it is incidence and prevalence slightly has risen in recent years due to lifestyle changes, reduced physical activity, obesity, and diet [3]. In some countries, colonoscopic screening for asymptomatic elderly people has been added to the National Colorectal Cancer Prevention Program (CRCCP) [4]. There is no routine screening program for colorectal cancer prevention by identifying and removing pre-cancerous lesions in Iran. Screening, detection of malignant tumors early, and removal of precursor lesions have key values in reducing colorectal cancer mortality. Cancer risk in diminutive colorectal polyps remains a significant health problem as over 80% of polyps found during colonoscopy are diminutive [5]. So, this study aimed to evaluate the pathological characteristics and the frequency of high-grade dysplasia in diminutive colorectal polyps in patients referred to our hospital for a colonoscopy.
Materials and Methods
The present study investigated the pathological characteristics and the frequency of high-grade dysplasia in diminutive colorectal polyps in individuals referred for a colonoscopy examination. In this retrospective cross-sectional study, all colonoscopy reports of individuals referred to Imam Reza University Hospital, Kermanshah, in the west of Iran from January 2017 to December 2018 to evaluate the pathological characteristics and the frequency of high-grade dysplasia in diminutive colorectal polyps. The protocol was approved by the Ethics Committee of Kermanshah University of Medical Sciences (No. IR.KUMS.REC.1399. 784), and the requirement for informed consent was waived for retrospective review of patient records. Exclusion criteria were a history of inflammatory bowel disease, colorectal cancer or colectomy, incomplete colonoscopy examination or clinical information, and poor bowel preparation. The following data were retrieved from each colonoscopy report: age, sex, cause of colonoscopy, family history of colon cancer or colorectal polyp, location and diameter of the polyp, and histopathological characteristics of the colonoscopically resected polyp specimens.
Statistical analysis
Statistical analysis was done using SPSS 22.0 (SPSS, Chicago, IL, USA). Continuous variables are presented as mean and standard deviation (SD), and categorical variables are expressed as the frequency with percentage. The chi-square test was applied to evaluate the correlation of the frequency of adenomatous polyps with other variables. A P value < 0.05 was considered to be statistically significant.
Results and Discussion
Overall, 250 patients who underwent colonoscopy had at least one biopsy specimen that showed diminutive colorectal polyps. Age ranged between 22 and 78 years, with a mean age (SD) of 56.8 (18.4). Of the 250 patients referred to the examination, 156 (62.4%) were male, and 94 (37.6%) were female. Adenomatous polyps were the most common pathological finding (n = 91; 36.4%), followed by hyperplastic polyps (n = 82; 32.8%). Also, 0.8% of neoplastic polyps had high-grade dysplasia. The rectum was the most common location for diminutive polyps, followed by the sigmoid and ascending colon. The frequency of adenocarcinoma in our study was 1/250 (0.4%); this patient was male and in the ≥ 60 age group. Adenocarcinoma was detected in the screening for colorectal cancer and is located in the sigmoid colon. Table 1 shows the characteristics and clinical features of the 250 individuals with diminutive colorectal polyps.
Table 2 compares demographic characteristics and anatomical locations of adenomatous polyps vs. non-adenomatous polyps. The percentage of adenomatous polyps by group age was 13.2% for 20-40 years, 67% for polyps 40-60 years, and 19.8% for polyps ≥ 60 years. A significant difference was observed among age groups between the two adenomatous and non-adenomatous polyps groups (P = 0.02). No significant differences in gender and location of the polyp were observed between the two groups (P=0.95). In this study, abdominal pain was the most common symptom of patients with polyps, with a frequency of 66.4% (278/513), while 19.6% had no symptoms. Long et al. found that 37.4% and 62.6% of symptomatic patients with polyps presented with abdominal pain and bowel habit alteration, respectively [6]. The authors also reported that 54.0% of 1,234 cases were asymptomatic. The presence of asymptomatic polyps may be explained by the fact that polyps can cause clinical symptoms only when they grow to a certain size.
In our research, the frequency of adenomatous polyps measuring < 5 mm was 36.4%. High-grade dysplasia was found in only 1.9% of small polyps. In addition, in our study, the frequency of adenocarcinoma in 250 polyps ≤5 mm was 1/250 (0.4%). The frequency of < 5 mm adenomatous polyps in other countries ranges between 0.08% and 0.3% [7, 8]. Both genetic and environmental factors may be associated with differences in results between the countries. However, adenomatous polyps with high-grade dysplasia have a high risk of developing into adenocarcinoma; therefore, it should not be ignored. The frequency of adenomatous polyps was higher in the proximal versus distal colon, consistent with most studies [9,10].
The high frequency of adenomas in the proximal colon may associate with obesity and lifestyle-related factors. Although it was not possible to assess the risk factors associated with colonic adenomatous polyps due to our study's retrospective nature, several studies have reported that obesity, metabolic syndrome, smoking, and alcohol are risk factors for colonic neoplasia [11]. It is still unclear whether or not the remaining polyps are a risk factor for progression to CRC.
CRC is usually an adenocarcinoma that occurs in the colon or rectum. It is the third most common cancer in the Iranian population, and it is incidence and prevalence slightly has risen in recent years due to lifestyle changes, reduced physical activity, obesity, and diet [3]. In some countries, colonoscopic screening for asymptomatic elderly people has been added to the National Colorectal Cancer Prevention Program (CRCCP) [4]. There is no routine screening program for colorectal cancer prevention by identifying and removing pre-cancerous lesions in Iran. Screening, detection of malignant tumors early, and removal of precursor lesions have key values in reducing colorectal cancer mortality. Cancer risk in diminutive colorectal polyps remains a significant health problem as over 80% of polyps found during colonoscopy are diminutive [5]. So, this study aimed to evaluate the pathological characteristics and the frequency of high-grade dysplasia in diminutive colorectal polyps in patients referred to our hospital for a colonoscopy.
Materials and Methods
The present study investigated the pathological characteristics and the frequency of high-grade dysplasia in diminutive colorectal polyps in individuals referred for a colonoscopy examination. In this retrospective cross-sectional study, all colonoscopy reports of individuals referred to Imam Reza University Hospital, Kermanshah, in the west of Iran from January 2017 to December 2018 to evaluate the pathological characteristics and the frequency of high-grade dysplasia in diminutive colorectal polyps. The protocol was approved by the Ethics Committee of Kermanshah University of Medical Sciences (No. IR.KUMS.REC.1399. 784), and the requirement for informed consent was waived for retrospective review of patient records. Exclusion criteria were a history of inflammatory bowel disease, colorectal cancer or colectomy, incomplete colonoscopy examination or clinical information, and poor bowel preparation. The following data were retrieved from each colonoscopy report: age, sex, cause of colonoscopy, family history of colon cancer or colorectal polyp, location and diameter of the polyp, and histopathological characteristics of the colonoscopically resected polyp specimens.
Statistical analysis
Statistical analysis was done using SPSS 22.0 (SPSS, Chicago, IL, USA). Continuous variables are presented as mean and standard deviation (SD), and categorical variables are expressed as the frequency with percentage. The chi-square test was applied to evaluate the correlation of the frequency of adenomatous polyps with other variables. A P value < 0.05 was considered to be statistically significant.
Results and Discussion
Overall, 250 patients who underwent colonoscopy had at least one biopsy specimen that showed diminutive colorectal polyps. Age ranged between 22 and 78 years, with a mean age (SD) of 56.8 (18.4). Of the 250 patients referred to the examination, 156 (62.4%) were male, and 94 (37.6%) were female. Adenomatous polyps were the most common pathological finding (n = 91; 36.4%), followed by hyperplastic polyps (n = 82; 32.8%). Also, 0.8% of neoplastic polyps had high-grade dysplasia. The rectum was the most common location for diminutive polyps, followed by the sigmoid and ascending colon. The frequency of adenocarcinoma in our study was 1/250 (0.4%); this patient was male and in the ≥ 60 age group. Adenocarcinoma was detected in the screening for colorectal cancer and is located in the sigmoid colon. Table 1 shows the characteristics and clinical features of the 250 individuals with diminutive colorectal polyps.
Table 2 compares demographic characteristics and anatomical locations of adenomatous polyps vs. non-adenomatous polyps. The percentage of adenomatous polyps by group age was 13.2% for 20-40 years, 67% for polyps 40-60 years, and 19.8% for polyps ≥ 60 years. A significant difference was observed among age groups between the two adenomatous and non-adenomatous polyps groups (P = 0.02). No significant differences in gender and location of the polyp were observed between the two groups (P=0.95). In this study, abdominal pain was the most common symptom of patients with polyps, with a frequency of 66.4% (278/513), while 19.6% had no symptoms. Long et al. found that 37.4% and 62.6% of symptomatic patients with polyps presented with abdominal pain and bowel habit alteration, respectively [6]. The authors also reported that 54.0% of 1,234 cases were asymptomatic. The presence of asymptomatic polyps may be explained by the fact that polyps can cause clinical symptoms only when they grow to a certain size.
In our research, the frequency of adenomatous polyps measuring < 5 mm was 36.4%. High-grade dysplasia was found in only 1.9% of small polyps. In addition, in our study, the frequency of adenocarcinoma in 250 polyps ≤5 mm was 1/250 (0.4%). The frequency of < 5 mm adenomatous polyps in other countries ranges between 0.08% and 0.3% [7, 8]. Both genetic and environmental factors may be associated with differences in results between the countries. However, adenomatous polyps with high-grade dysplasia have a high risk of developing into adenocarcinoma; therefore, it should not be ignored. The frequency of adenomatous polyps was higher in the proximal versus distal colon, consistent with most studies [9,10].
The high frequency of adenomas in the proximal colon may associate with obesity and lifestyle-related factors. Although it was not possible to assess the risk factors associated with colonic adenomatous polyps due to our study's retrospective nature, several studies have reported that obesity, metabolic syndrome, smoking, and alcohol are risk factors for colonic neoplasia [11]. It is still unclear whether or not the remaining polyps are a risk factor for progression to CRC.
Table 1. Characteristics of the study participants
| Number | Percent | |
| Gender | ||
| Male | 156 | 62.4 |
| Female | 94 | 37.6 |
| Age group (yr) | ||
| 20-40 | 51 | 20.4 |
| 40-60 | 140 | 56 |
| ≥60 | 59 | 23.6 |
| Polyp size | ||
| 2 | 56 | 22.4 |
| 3 | 116 | 46.4 |
| 4 | 41 | 16.4 |
| 5 | 37 | 14.8 |
| Polyp location | ||
| Cecum | 33 | 13.2 |
| Ascending colon | 24 | 9.6 |
| Hepatic flexure | 5 | 2.0 |
| Transverse colon | 28 | 11.2 |
| Splenic flexure | 10 | 4.0 |
| Descending colon | 27 | 10.8 |
| Sigmoid colon | 63 | 25.2 |
| Rectum | 60 | 24.0 |
| Histopathology | ||
| Adenomas | 91 | 36.4 |
| Hyperplastic polyp | 82 | 32.8 |
| Inflammatory polyp | 77 | 30.8 |
| Grade dysplasia | ||
| Non- dysplasia | 159 | 63.6 |
| Low | 46 | 18.4 |
| Mild | 6 | 2.4 |
| Moderate | 32 | 12.8 |
| Moderate to severe | 4 | 1.6 |
| Severe | 2 | 0.8 |
| Adenocarcinoma | 1 | 0.4 |
| Family history of the polyp or colorectal cancer | ||
| Yes | 157 | 62.8 |
| No | 65 | 26 |
| I do not know | 28 | 11.2 |
| Reason of referral | ||
| Abdominal pain | 162 | 64.8 |
| Chronic constipation | 36 | 14.4 |
| Bleeding per rectum | 34 | 13.6 |
| Colonic dilation and obstruction | 19 | 7.6 |
| Screening | 49 | 19.6 |
Table 2. Demographic details and anatomical locations of polyps in adenomatous and non- adenomatous polyps
| Adenomatous polyps (91) n (%) |
Non-adenomatous polyps (159) n (%) |
P value | |
| Gender | |||
| Male | 57 (62.6) | 99 (62.3) | 0.953 |
| Female | 34 (37.4) | 60 (37.7) | |
| Age group (yr) | |||
| 20-40 | 12 (13.2) | 39 (24.5) | 0.022 |
| 40-60 | 61 (67.0) | 79 (49.7) | |
| ≥60 | 18 (19.8) | 41 (25.8) | |
| Location of polyp | |||
| Cecum | 11 (12.1) | 22 (13.8) | 0.152 |
| Ascending colon | 12 (13.2) | 12 (7.5) | |
| Hepatic flexure | 0 | 5 (3.1) | |
| Transverse colon | 13 (14.3) | 15 (9.4) | |
| Splenic flexure | 1 (1.1) | 9 (5.7) | |
| Descending colon | 7 (7.7) | 20 (12.7) | |
| Sigmoid colon | 25 (27.5) | 38 (23.9) | |
| Rectum | 22 (24.2) | 38 (23.9) |
A recent systematic review of 9 studies with 721 patients found that of 1,034 adenomas sized 1 to 9 mm, 6% progressed to advanced adenomas over time [12]. Only one polyp among polyps measuring 1-9 mm progressed to cancer during 2-3 years follow-up.
Nevertheless, their study had some limitations, including 1. a short mean follow-up of all studies included in this review, 2. a small sample size, 3. interobserver variation in interpreting the results, 4. re-detecting the unreliability of the primary polyp as well as partial or even total removal of the polyp can alter its normal growth. However, further studies are needed to clarify whether colonoscopy should be performed in patients with polyps < 5 mm in size.
A major limitation of the present study was its retrospective nature; therefore, risk factors such as smoking, diet, drug medications, and physical activity levels were not studied. The research findings were limited to a single hospital in Iran.
Conclusion
Our results showed that about one-third of diminutive colorectal polyps are adenomatous, which was more frequent in elderly and male patients. The frequency of high-grade dysplasia was very low in diminutive polyps; nevertheless, one patient had adenocarcinoma. These findings emphasize the urgent need for a CRC screening plan in the Iranian population to improve therapeutic outcomes.
Conflicts of Interest
There is no conflict of interest to declare.
Acknowledgments
The authors would like to thank the Clinical Research Development Center of Imam Reza Hospital, affiliated with Kermanshah University of Medical Sciences, for their kind support. This study received financial support from Kermanshah University of Medical Sciences, Iran (Grant Number. 990718).
Nevertheless, their study had some limitations, including 1. a short mean follow-up of all studies included in this review, 2. a small sample size, 3. interobserver variation in interpreting the results, 4. re-detecting the unreliability of the primary polyp as well as partial or even total removal of the polyp can alter its normal growth. However, further studies are needed to clarify whether colonoscopy should be performed in patients with polyps < 5 mm in size.
A major limitation of the present study was its retrospective nature; therefore, risk factors such as smoking, diet, drug medications, and physical activity levels were not studied. The research findings were limited to a single hospital in Iran.
Conclusion
Our results showed that about one-third of diminutive colorectal polyps are adenomatous, which was more frequent in elderly and male patients. The frequency of high-grade dysplasia was very low in diminutive polyps; nevertheless, one patient had adenocarcinoma. These findings emphasize the urgent need for a CRC screening plan in the Iranian population to improve therapeutic outcomes.
Conflicts of Interest
There is no conflict of interest to declare.
Acknowledgments
The authors would like to thank the Clinical Research Development Center of Imam Reza Hospital, affiliated with Kermanshah University of Medical Sciences, for their kind support. This study received financial support from Kermanshah University of Medical Sciences, Iran (Grant Number. 990718).
References
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[2]. Amersi F, Agustin M, Ko CY. Colorectal cancer: epidemiology, risk factors, and health services. Clinics in colon and rectal surgery. Clin Colon Rectal Surg. 2005; 18(3): 133-40.
[3]. Dolatkhah R, Somi MH, Kermani IA, Ghojazadeh M, Jafarabadi MA, Farassati F, et al. Increased colorectal cancer incidence in Iran: a systematic review and meta-analysis. BMC Public Health 2015; 15(1): 1-14.
[4]. Heijnen ML, Landsdorp-Vogelaar I. CRC screening in the Netherlands. From pilot to national programme. 2014. Available from: http://www.rivm.nl/en/Topics/B/Bowel_cancer_screening_programme.
[5]. Wang LM, East JE. Diminutive polyp cancers and the DISCARD strategy: Much ado about nothing or the end of the affair? Gastrointest Endosc. 2015; 82(2): 385-88.
[6]. Long X, Li X, Ma L, Lu J, Liao S, Gui R. Clinical and endoscopic-pathological characteristics of colorectal polyps: an analysis of 1,234 cases. Int J Clin Exp Med. 2015; 8(10): 19367.
[7]. Jeong YH, Kim KO, Park CS, Kim SB, Lee SH, Jang BI. Risk factors of advanced adenoma in small and diminutive colorectal polyp. J Korean Med Sci. 2016; 31(9): 1426-430.
[8]. Kim DH, Pickhardt PJ, Taylor AJ, Leung WK, Winter TC, Hinshaw JL, et al. CT colonography versus colonoscopy for the detection of advanced neoplasia. N Engl J Med. 2007; 357(14): 1403-412.
[9]. Kruger J, Katsidzira L, Setshedi M, Thomson S. Prevalence and characteristics of incidental colorectal polyps in patients undergoing colonoscopy at a South African tertiary institution. S Afr Med J. 2020; 110(12): 1191-194.
[10]. Renehan AG, Tyson M, Egger M, Heller RF, Zwahlen M. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet 2008; 371(9612): 569-78.
[11]. Trabulo D, Ribeiro S, Martins C, Teixeira C, Cardoso C, Mangualde J, et al. Metabolic syndrome and colorectal neoplasms: An ominous association. World J Gastroenterol. 2015; 21(17): 5320.
[12]. Vleugels JL, Hazewinkel Y, Fockens P, Dekker E. Natural history of diminutive and small colorectal polyps: a systematic literature review. Gastrointest Endosc. 2017; 85(6): 1169-176.
[2]. Amersi F, Agustin M, Ko CY. Colorectal cancer: epidemiology, risk factors, and health services. Clinics in colon and rectal surgery. Clin Colon Rectal Surg. 2005; 18(3): 133-40.
[3]. Dolatkhah R, Somi MH, Kermani IA, Ghojazadeh M, Jafarabadi MA, Farassati F, et al. Increased colorectal cancer incidence in Iran: a systematic review and meta-analysis. BMC Public Health 2015; 15(1): 1-14.
[4]. Heijnen ML, Landsdorp-Vogelaar I. CRC screening in the Netherlands. From pilot to national programme. 2014. Available from: http://www.rivm.nl/en/Topics/B/Bowel_cancer_screening_programme.
[5]. Wang LM, East JE. Diminutive polyp cancers and the DISCARD strategy: Much ado about nothing or the end of the affair? Gastrointest Endosc. 2015; 82(2): 385-88.
[6]. Long X, Li X, Ma L, Lu J, Liao S, Gui R. Clinical and endoscopic-pathological characteristics of colorectal polyps: an analysis of 1,234 cases. Int J Clin Exp Med. 2015; 8(10): 19367.
[7]. Jeong YH, Kim KO, Park CS, Kim SB, Lee SH, Jang BI. Risk factors of advanced adenoma in small and diminutive colorectal polyp. J Korean Med Sci. 2016; 31(9): 1426-430.
[8]. Kim DH, Pickhardt PJ, Taylor AJ, Leung WK, Winter TC, Hinshaw JL, et al. CT colonography versus colonoscopy for the detection of advanced neoplasia. N Engl J Med. 2007; 357(14): 1403-412.
[9]. Kruger J, Katsidzira L, Setshedi M, Thomson S. Prevalence and characteristics of incidental colorectal polyps in patients undergoing colonoscopy at a South African tertiary institution. S Afr Med J. 2020; 110(12): 1191-194.
[10]. Renehan AG, Tyson M, Egger M, Heller RF, Zwahlen M. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet 2008; 371(9612): 569-78.
[11]. Trabulo D, Ribeiro S, Martins C, Teixeira C, Cardoso C, Mangualde J, et al. Metabolic syndrome and colorectal neoplasms: An ominous association. World J Gastroenterol. 2015; 21(17): 5320.
[12]. Vleugels JL, Hazewinkel Y, Fockens P, Dekker E. Natural history of diminutive and small colorectal polyps: a systematic literature review. Gastrointest Endosc. 2017; 85(6): 1169-176.
Type of Study: Research |
Subject:
Pathology
Received: 2021/11/28 | Accepted: 2023/03/1 | Published: 2023/03/1
Received: 2021/11/28 | Accepted: 2023/03/1 | Published: 2023/03/1
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