Abstract：
OBJECTIVE: 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.
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.
CONCLUSIONS: 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.
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.
CONCLUSIONS: 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.
摘要：
目的：结直肠癌（CRC）被认为是世界上最常见的癌症之一。发现锯齿状息肉是CRC的前体病变。BRAF突变（V600E）与这些病变的发展密切相关。以前在阿曼没有关于锯齿状息肉中BRAF免疫组织化学表达的研究。我们研究的主要目的是评估阿曼人群锯齿状结直肠息肉中BRAF（V600E）突变的患病率。次要目标是评估锯齿状息肉的患病率及其特征：类型，位点和大小以及BRAF(V600E)突变与息肉类型的关系,站点和大小。
方法：91例增生性息肉（HP）（76.5％），研究了24例无柄锯齿状病变（SSL）（20.2％）和4例低级别异型增生的管状腺瘤（3.4％）的BRAF（V600E）免疫组化表达。没有出现传统锯齿状腺瘤（TSA）的病例。包括颅咽管瘤和甲状腺乳头状癌的对照病例。
结果：BRAF（V600E）IHC在63例HP息肉中呈阳性（69.2％），13例SSLs（54.2%），无腺瘤性息肉。大多数阳性息肉（75.0%）大小≤5mm，17.9%为5-10毫米，7.1%为≥10毫米。大多数BRAF(V600E)阳性息肉(68.1%)位于远端结肠，31.9%位于近端结肠。大多数BRAF（V600E）阳性病例表现为多发性息肉（61.8％）。管状腺瘤均未显示任何BRAF（V600E）阳性。
结论：锯齿状息肉因其发展为CRC的潜力而广为人知。免疫组织化学是检测BRAF(V600E)突变的简单且可重复的方法。我们的研究表明，阿曼人群中锯齿状息肉中BRAF突变的患病率很高（64.3％）。这些息肉大多数是HP和SSL；大小≤5毫米，位于远端结肠。
方法：91例增生性息肉（HP）（76.5％），研究了24例无柄锯齿状病变（SSL）（20.2％）和4例低级别异型增生的管状腺瘤（3.4％）的BRAF（V600E）免疫组化表达。没有出现传统锯齿状腺瘤（TSA）的病例。包括颅咽管瘤和甲状腺乳头状癌的对照病例。
结果：BRAF（V600E）IHC在63例HP息肉中呈阳性（69.2％），13例SSLs（54.2%），无腺瘤性息肉。大多数阳性息肉（75.0%）大小≤5mm，17.9%为5-10毫米，7.1%为≥10毫米。大多数BRAF(V600E)阳性息肉(68.1%)位于远端结肠，31.9%位于近端结肠。大多数BRAF（V600E）阳性病例表现为多发性息肉（61.8％）。管状腺瘤均未显示任何BRAF（V600E）阳性。
结论：锯齿状息肉因其发展为CRC的潜力而广为人知。免疫组织化学是检测BRAF(V600E)突变的简单且可重复的方法。我们的研究表明，阿曼人群中锯齿状息肉中BRAF突变的患病率很高（64.3％）。这些息肉大多数是HP和SSL；大小≤5毫米，位于远端结肠。
