Department of Surgery, University Hospital Waterford/University College Cork, Cork, Ireland.
Department of Colorectal Surgery, Digestive Diseases and Surgery Institute, Cleveland Clinic Foundation, Cleveland, Ohio.
Dis Colon Rectum. 2018 Dec;61(12):1380-1385. doi: 10.1097/DCR.0000000000001208.
Sessile serrated adenomas/polyps are potentially premalignant colorectal lesions that are precursors to colorectal cancer arising via CpG island methylator phenotype. They are caused by the combination of a BRAF mutation and promoter hypermethylation. DNA methylation is an age-dependent phenomenon in the right colon, and we would expect the occurrence and severity of serrated neoplasia to reflect this.
The purpose of this study was to document the natural history of sessile serrated adenomas/polyps, including the ages at which they appear and the ranges of their number, size, and associated lesions.
This was a retrospective cohort study.
The study was conducted at a tertiary referral center.
Consecutive patients with sessile serrated adenomas/polyps removed between 2006 and 2015 were included. Patients with IBD, familial adenomatous polyposis, Lynch syndrome, serrated polyposis, and hereditary nonpolyposis colorectal cancer were excluded.
Age at which polyps were first diagnosed, location and size of polyps, demographics, and family history were measured.
A total of 440 patients had 668 sessile serrated adenomas/polyps, 257 (58%) also had ≥1 adenoma, and 28 (6%) had a history of colorectal cancer. Mean age at diagnosis was 68 ± 11 years, and 45% were men. Two hundred had had ≥1 colonoscopy before the diagnosis of the first sessile serrated adenomas/polyps. A total of 136 patients (31%) had multiple sessile serrated adenomas/polyps, including 24% synchronous and 10% metachronous. The range of total cumulative sessile serrated adenomas/polyps was from 1 to 7. A total of 554 (83%) of 668 sessile serrated adenomas/polyps were right sided; 48% were ≥1 cm diameter and 22% were >2 cm. The size of the first sessile serrated adenomas/polyps in those diagnosed under age 50 years averaged 10 mm, those between 50 and 60 years averaged 12 mm, and those between 60 and 70 years averaged 12 mm.
No measurement of methylation or BRAF mutations in polyps or normal mucosa and a lack of subclassification of hyperplastic polyps limited this study.
The age of onset of sessile serrated adenomas/polyps varies, but the pattern is consistent with increasing methylation in the mucosa. Early negative colonoscopies predict a low risk of methylator cancers. See Video Abstract at http://links.lww.com/DCR/A736.
无蒂锯齿状腺瘤/息肉是一种潜在的癌前结直肠病变，是通过 CpG 岛甲基化表型发生的结直肠癌的前体。它们是由 BRAF 突变和启动子过度甲基化共同引起的。DNA 甲基化是右结肠中一种随年龄增长而出现的现象，我们预计锯齿状肿瘤的发生和严重程度会反映这一点。
本研究旨在记录无蒂锯齿状腺瘤/息肉的自然史，包括其出现的年龄以及其数量、大小和相关病变的范围。
这是一项回顾性队列研究。
该研究在一家三级转诊中心进行。
纳入 2006 年至 2015 年间切除的无蒂锯齿状腺瘤/息肉的连续患者。排除患有炎症性肠病、家族性腺瘤性息肉病、林奇综合征、锯齿状息肉和遗传性非息肉病结直肠癌的患者。
首次诊断时的年龄、息肉的位置和大小、人口统计学资料和家族史。
共有 440 例患者有 668 个无蒂锯齿状腺瘤/息肉，其中 257 例（58%）还至少有 1 个腺瘤，28 例（6%）有结直肠癌病史。诊断时的平均年龄为 68±11 岁，其中 45%为男性。200 例患者在诊断出第一个无蒂锯齿状腺瘤/息肉之前至少进行过 1 次结肠镜检查。共有 136 例（31%）患者有多发性无蒂锯齿状腺瘤/息肉，包括 24%的同时性和 10%的异时性。无蒂锯齿状腺瘤/息肉的总累积数范围为 1 至 7。668 个无蒂锯齿状腺瘤/息肉中有 554 个（83%）位于右侧；48%的直径≥1cm，22%的直径>2cm。50 岁以下诊断的无蒂锯齿状腺瘤/息肉的平均大小为 10mm，50-60 岁之间诊断的平均大小为 12mm，60-70 岁之间诊断的平均大小为 12mm。
本研究未测量息肉或正常黏膜中的甲基化或 BRAF 突变，并且缺乏增生性息肉的分类，限制了本研究。
无蒂锯齿状腺瘤/息肉的发病年龄不同，但模式与黏膜中甲基化的增加一致。早期阴性结肠镜检查预测甲基化癌症的风险较低。
