Histopathology of Polyps and Its Clinical Correlation in Sample of Iraqi Patients Undergoing Colonoscopic Examination

Background /Aims: Colorectal cancer is the third most common cancer in 2018, the objective of our study was to describe the types and patterns of colorectal polyps in patients presenting to a tertiary care referral center in Baghdad. We also assessed the polyp detection rate (PDR) and adenoma detection rate (ADR). Patients & Methods: This is single-institution, descriptive cross-sectional study of consenting 103 patients who had colonoscopy done at the Endoscopy Unit of Baghdad teaching hospital, IRAQ from the 1st of June 2018 to 31st of March 2019 after taking verbal consent, The data collected included: Age, sex, Family history of colorectal malignancies and indication for the current colonoscopy. Results: One thousand and thirty patients were included in the study with a mean age of 44 years (SD = 16), with 560 males representing 54.4% and 470 females representing 45.66%.The polyp detection rate in colonoscopies was 19.4% and the adenoma detection rate was 13.6%. Polyps were found and removed in 200 patients, 40% of the removed polyps were tubular adenomas, tubulovillous adenomas in 20%, villous adenomas in 10%, hyperplastic polyps in 5%. The majority of the polyps were in the distal colon in 80% of patients with polyps. Conclusions: The polyp detection rate was (19.4%) and adenoma detection rate was (13.6%). The majority of polyps were detected in distal colon.


Introduction and Literature Review
According to the WHO, colorectal cancer is the third most common cancer in 2018, both sexes, all ages. Almost 55% of the cases occur in more developed regions but with less mortality than in less developed regions (The global cancer observatory. 2018).
Colorectal cancer (CRC) is one of the few diseases for which screening programs have shown to be efficacious in decreasing both the incidence as well as the mortality. Randomized controlled trials have demonstrated that repetitive fecal occult blood testing (FOBT) reduces the mortality from CRC by 16%, while once-only flexible sigmoidoscopy reduces CRC incidence and mortality by 18% and 28%, respectively (Garborg, Holme, Loberg, Kalager, Adami, & Bretthauer, 2013).
Colorectal polyp (CP) is a grossly visible protrusion from the mucosal of the large bowel. They may be classified pathologically as a nonneoplastic hamartoma (e.g. juvenile polyp), a hyperplastic mucosal proliferation (hyperplastic polyp), or an adenomatous polyp .Only adenomas are clearly premalignant, and only a minority of adenomatous polyps evolve into cancer (Anthony et al., 2018).
Clinically, the probability of an adenomatous polyp becoming a cancer depends on: 2. The polyps histological features.
Polyps may be pedunculated (stalked) or sessile (flat-based) adenomatous or serrated ( Invasive cancers develop more frequently in sessile, serrated polyps. Colonic polyps may be divided into 2 major groups: neoplastic (adenomas and carcinomas) and non-neoplastic. The adenomas and carcinomas share a characteristic-cellular dysplasia-but they may be subdivided according to the relative prominence of certain microscopic features. Histologically, adenomatous polyps may be (1) tubular, (2) villous or (3) tubulovilous. The increased realization that serrated polyps also have malignant potential now permits classifying them as neoplastic polyps (Anthony et al., 2018).
Submucosal lesions also can impart a polypoid appearance to the overlying mucosa and therefore are briefly mentioned even though they are not true polyps (Feldman & Friedman, 2016).
In the era of screening colonoscopy, the colorectal polyp detection rate is increasing. Colonoscopy continues to be considered as the gold standard screening tool for colon cancer prevention because it enables the removal of precancerous adenomas (Visovan, Tantau, Ciobanu, Pascu, & Tantau, 2014).
When calculating the adenoma detection rate (ADR), the numerator included all colonoscopies where at least one polyp was found to be adenomatous, whether the pathology was tubular or villous or the polyp had high-grade dysplasia or adenocarcinoma.

Aim of the Study
The aim of our study was to describe the types and patterns of colorectal polyps in patients presenting to a tertiary care referral center in Baghdad. We also assessed the polyp detection rate (PDR), polyps per colonoscopy and adenoma detection rate (ADR).

Study Design and Sample
We conducted a single-institution, descriptive cross-sectional study of 1030 patients who had colonoscopy done at the Endoscopy Unit of Baghdad teaching hospital, IRAQ from the 1st of June 2018 to the 31st of March 2019 after taking verbal consent .
for the colonoscopy.

Endoscopically Procedure
Colonoscopy was carried out after bowel preparation with polyethylene glycol without sedation.
The colonoscopy was performed by the senior gastroenterologist or by a trainee under the direct supervision of senior gastroenterologist using (Olympus LUCERA CLV-260) endoscope and endoscopic diagnosis was made on gross visualization of the lesions.
The location, number, shape, size and histology of polyps detected and removed were documented.
The location of the polyps were defined as distal colon (up to the splenic flexure) and proximal colon (from caecum to splenic flexure).
The polyps are classified according to their morphology to (sessile or pedunculated).
In the event of multiple polyps, only the size of the largest was considered for the purposes of analysis.

Histopathological Examination
Biopsies were sent to Department of Pathology for histopathological examination. Histopathology was performed as per the standard protocol of the hospital.

Inclusion criteria
A total of 1030 Iraqi adults patients who underwent a colonoscopy for common indications were selected randomly and included in the study.
Exclusion criteria 1. History of previous colon polyp.
(To avoid falsely high or low detection rate for CRC and polyps)

Statistical Analysis
Data analysis included descriptive statistics computed for continuous variables, including means, standard deviations (SDs), minimum and maximum values, as well as 95% confidence intervals (CIs). Frequencies are used for categorical variables.
Data was entered and analyzed using IBM SPSS Statistics 25.0
Family history of colonic malignancy was positive in 2.9% (n=3) of the patients.

Figure 2. Morphology of colorectal polyps
The number of polyps detected during colonoscopy ranged (1 to 7) with 65% (n=130) of patients had single polyp.
The majority of the detected polyps were in the distal colon 80% (n=160), and 20% (n=40) were in the proximal colon ( Figure 3).
Carcinoma was detected in 5% (n=10) of the patients.
The entire detected inflammatory polyp were sessile in morphology, the tubular adenomas were mixed in morphology with both pedunculated and sessile morphology (  The neoplastic polyps were distributed over the proximal and distal colon, while all the nonneoplastic polyps were found in the distal colon (Table 5) (P-value 0.001).

Discussion
Colorectal polyp prevalence differs between different countries.
The importance of knowing the distribution of colorectal polyp in each country is because it may affect the efficacy of screening programs and also the prevalence of adenomas that roughly equivalent to the risk of colorectal malignancies (Patel K& Hoffman NE.2001), (Johannsen, Momsen, & Jacobsen, 1989).
The PDR was pretty close in our study but the ADR was higher than Saudi Arabia.
In western countries the ADR was much higher, a retrospective chart review from Mayo Clinic, Arizona, found that the ADR reached up to 42% for some gastroenterologists (Boroff, Gurudu, & Hentz, 2013), while in Germany was 31.7% (Schramm, Mbaya, & Franklin, 2015), This association between adenoma detection rate reflects the incidence of colon cancer in these geographical areas.
The polyps were detected equally in both sexes 50% (n=10) for each.
The most common indication for colonoscopy in our population sample was lower gastrointestinal bleeding 49.5% (n=51), and it's the most common indication in patients with detected polyps 65% (n=13), of note screening colonoscopy as an indication for colonoscopy was absent in our sample.