Investigating The Frequency of Serrated Polyps/Adenomas and Their Subtypes in Colonic Polyp Samples

Analysis of Immunohistochemical Expression of BRAF (V600E) Mutation in Serrated Colorectal Polyps: A Study from Tertiary Hospital in Oman

BACKGROUND AND AIM

Colorectal cancer (CRC) is considered one of the most common cancers in the world. Serrated polyps were found to be precursor lesions for CRC. BRAF mutation (V600E) has been strongly linked to the development of these lesions. No previous study concerning BRAF immunohistochemical expression in serrated polyps- was done in Oman. The primary objective of our study was to assess the prevalence of BRAF (V600E) mutation in serrated colorectal polyps in the Omani population. The secondary objectives were to assess the prevalence of serrated polyps and their characteristic features: type, site and size as well as the relationship between BRAF (V600E) mutation and polyp type, site and size.

MATERIALS AND METHODS

Ninety-one hyperplastic polyps (HP) (76.5%), 24 sessile serrated lesions (SSL) (20.2%) and 4 cases of tubular adenomas with low grade dysplasia (3.4%) were studied for BRAF (V600E) immunohistochemical expression. No case of traditional serrated adenoma (TSA) was present. Control cases of craniopharyngioma and papillary thyroid carcinoma were included.

RESULTS

BRAF (V600E) IHC was positive in 63 of the HP polyps (69.2%), 13 SSLs (54.2%) and none of the adenomatous polyps. The majority of positive polyps (75.0%) were ≤5 mm in size, 17.9% were 5-10 mm and 7.1% were ≥10 mm in size.  The majority of BRAF (V600E) positive polyps (68.1 %) were in the distal colon and 31.9 % were in the proximal colon. The majority of positive cases for BRAF (V600E) were showing multiple polyps (61.8 %). None of the tubular adenomas showed any BRAF (V600E) positivity.

CONCLUSION

Serrated polyps are now well known for their potential to develop CRC. Immunohistochemistry is an easy and reproducible way to detect BRAF (V600E) mutation. Our study showed there is high prevalence (64.3%) of BRAF mutation in serrated polyps in the Omani population. The majority of these polyps- were HP and SSL; and ≤5 mm in size and located in the distal colon.

Bleeding After Endoscopic Resection of Colonic Adenomatous Polyps Sized 4-10 mm

Introduction: Colonoscopy with polypectomy is an efficacious procedure in reducing the risk of colorectal cancer development, the precursor are adenomatous polyps. The most common method for resection of polyps measuring 4-10 mm are cold (CSP) and hot snare polypectomy (HSP). CSP has a lower incidence of adverse events, especially delayed post-polypectomy bleeding. Aim: To evaluate the presence of immediate and delayed bleeding in the cold snare polypectomy of sub-centimeter polyps of the colon compared with hot snare polypectomy. Materials and Methods: This prospective clinical study is comprised all patients who were incidentally detected to have adenomatous colonic polyps measuring 4-10 mm during a colonoscopy screening. Polypectomy was done with (hot snare) or without electrocautery (cold snare). After removal of polyps, immediate bleeding, delayed bleeding, and methods for were analyzed. Results: The CSP and HSP groups included 116 patients, 113 (54.4%) polyps in 61 (52.6%) patients with CSP while 95 (45.6%) polyps in 55 (47.4%) patients with HSP. 25 (22.1%) polyps after CSP had immediate bleeding. In 5 patients (20.0%), five hemostatic clips were inserted after CSP for bleeding longer than 150 sek. The average percentage difference between immediate bleeding versus total number of resected polyps using the cold snare method is not statistically significant (p<0.05) (Difference test, p=0.0000). Delayed bleeding was not registered using this method. In the second investigated group (HSP), one patient had delayed bleeding. This was stopped with 2 clips. Immediate bleeding was not registered. Conclusion: CSP is safer than HSP in resecting colon polyps sized 4-10 mm, without risk of delayed bleeding.

Clinicopathologic Features of Colorectal Polyps in Shahid Beheshti University of Medical Sciences (SBMU)

Aim: This study was designed to report epidemiologic findings of polyps in Iranian patients, and predict histology of polyp regarding to demographic and colonoscopic findings. Background: Classification of colorectal polyps had been revised in the past two decades and there is a need for polyp categorization in the Iranian Health System. Patients and methods: In this retrospective study, the medical records of patients with colonoscopic diagnosis of polyp in pathology departments of SBMU affiliated teaching hospitals were reviewed. Patient’s slides evaluated and demographics findings were assessed. The anatomical location, macroscopic appearance including size and histological assessment of all polyps were recorded. Results: From total number of 1106 polyps (detected in 862 patients), adenomatous polyps (638 [57.7%]) were the most prevalent findings, followed by colon mucosal tag (184[16.6%]), hyperplastic and serrated polyps (122[11%]), inflammatory polyps (110[9.9%]), hamartomatous (21[1.9%]), and malignant lesions (13[1.2%]). Multivariate logistic regression showed age (each one year increasing age; odds ratio [OR] = 1.026, 95%confidence interval [CI] = 1.016–1.036, p < 0.0001), location of polyp (right colon; OR = 1.905, 95%CI = 1.366–2.656, p < 0.0001), and polyp size of 5-10 mm (OR = 1.662, 95%CI = 1.214–2.276, p = 0.002), and polyp size of >10 mm (OR = 2.778, 95%CI = 1.750–4.411, p< 0.0001) were independently associated with neoplastic polyps. Also, polyp size of >10 mm (OR= 2.613, 95%CI= 1.083-6.307, p=0.033), tubulovillous pattern of polyp (OR= 3.508, 95%CI= 1.666-7.387, p=0.001) and villous pattern of polyp (OR= 10.444, 95%CI= 4.211-25.905, p<0.0001) were associated with high grade dysplasia in neoplastic polyps. Conclusion: Increased age, location of polyp (right colon), increased size of polyp and villous component of polyp could classify patients in high risk groups.

Can the rate and location of sessile serrated polyps be part of colorectal Cancer disparity in African Americans?

BACKGROUND

Up to 30% of colorectal cancers develop through the serrated pathway. African Americans (AAs) suffer a disproportionate burden of colorectal cancer. The aim of this study was to evaluate clinicopathological features of AA patients diagnosed with sessile serrated polyps (SSPs).

METHODS

We conducted a retrospective study of all colonoscopies (n = 12,085) performed at Howard University Hospital, from January 1st, 2010 to December 31st, 2015, of which 83% were in AA patients, (n = 10,027). Among AAs, pathology reports confirmed 4070 patients with polyps including 252 with SSPs. Demographic and clinical variables (i.e. sex, age, BMI, anatomic location, clinical symptoms, polyp size, and clinical indications were collected at colonoscopy.

RESULTS

In the AA population, the median age was 56 with interquartile range (IQR) of 51 to 62 years, 54% were female, and 48% had a BMI > 30. The most common reason for colonoscopy was screening (53%), whereas the prevalent reasons for diagnostic colonoscopies were changes in bowel habits (18%) and gastrointestinal bleeding (17%). The total number of SSPs among the 252 AA (diagnosed with SSPs) was 338. Of these, 9% (n = 29/338) had some degree of cytological dysplasia, primarily in the ascending colon (n = 6/42, 14%), Transverse colon (n = 2/16, 13%) and rectosigmoid (n = 19/233, 8%). About 24% of patients had more than 2 polyps. Most patients (76%) had distal SSPs (rectal and rectosigmoid), in comparison to 14% of proximal polyps and 10% of bilateral locations. Median SSA/P size for all locations was 0.6 cm.

CONCLUSION

The prevalence of SSPs accounts for 6% of all polyps in AA patients and was diagnosed in 2.5% of all colonoscopies (n = 252/10,027), which is higher than Caucasians in the US. SSPs were predominantly located in the left side, as compared to published literature showing the predominance in the right side of the colon. Screening of CRC will have the chance to detect high risk SSA/P in this population.

Variation in Pathologist Classification of Colorectal Adenomas and Serrated Polyps

OBJECTIVES

Endoscopist quality measures such as adenoma detection rate (ADR) and serrated polyp detection rates (SPDRs) depend on pathologist classification of histology. Although variation in pathologic interpretation is recognized, we add to the literature by quantifying the impact of pathologic variability on endoscopist performance.

METHODS

We used natural language processing to abstract relevant data from colonoscopy and related pathology reports performed over 2 years at four clinical sites. We quantified each pathologist's likelihood of classifying polyp specimens as adenomas or serrated polyps. We estimated the impact on endoscopists' ADR and SPDR of sending their specimens to pathologists with higher or lower classification rates.

RESULTS

We observed 85,526 colonoscopies performed by 119 endoscopists; 50,453 had a polyp specimen, which were analyzed by 48 pathologists. There was greater variation across pathologists in classification of serrated polyps than in classification of adenomas. We estimate the endoscopist's average SPDR would be 0.5% if all their specimens were analyzed by the pathologist in our sample with the lowest classification rate and 12.0% if all their specimens were analyzed by the pathologist with the highest classification rate. In contrast, the endoscopist's average ADR would be 28.5% and 42.4% if their specimens were analyzed by the pathologist with lowest and highest classification rate, respectively.

CONCLUSIONS

There is significant variation in pathologic interpretation, which more substantially affects endoscopist SPDR than ADR.