Presentation on theme: "The Adenoma/Carcinoma Sequence in the Colon"— Presentation transcript:
1 The Adenoma/Carcinoma Sequence in the Colon A colon with an adenoma isat increased risk to developa carcinomaThe more adenomas there are,the greater the risk
2 The Adenoma/Carcinoma Sequence in the Colon removing adenomas decreases the incidence of colorectal carcinomabig adenomas are at risk to contain carcinomas and are also markers of cancer risk for the rest of the colon
3 The Sporadic Adenoma-Carcinoma Sequence in the Colon Endoscopy with removal of adenomas can prevent colorectal carcinoma.A ton of adenomas are removed every yearFew small cancers are picked up during routine endoscopyThe number of colorectal carcinomas isn’t decreasing, but the deaths are!
4 Colorectal carcinoma (USA) American Cancer Society Estimates New cases , , ,920Deaths 56, , ,920Males and females about equalWhy???Cancers are stable while the population at risk is increasing. Cancer deaths are down.
5 Data from the CDC, 7/5/11From , the age adjusted colorectal cancer incidence decreased by 13% and the mortality decreased by 12%. Screening increased by 13% from
6 We know which adenomas are at risk to contain invasive carcinomabutwe have no idea which adenomas are the precursors of most ordinary colorectal carcinomas
7 Small Adenoma with Highest-GD: the real cancer precursor?
8 Case based practical approaches to adenomas using the information taken from the adenoma-carcinoma sequence to make clinical decisions
12 The key is the lymphatics. Normal colonic mucosa has very few
13 Metastatic carcinoma outlines lymphatics at the very base of the mucosa and in the submucosa Muscularis mucosae
14 Recommendation: In the colon: the diagnosis of “adenocarcinoma” is limited to dysplastic epithelium that invades into the submucosa.The same epithelium confined to the mucosa is called “high-grade dysplasia”Therefore, “carcinoma-in-situ” and“intramucosal carcinoma” do not exist in the colon!This is our approach at the U of M.
15 Summary of this adenoma Endo: 2 cm pedunculated polypProc: PolypectomyMicro: Adenoma; it hasmultifocal high-grade dysplasiaDx: Adenoma (at the U of M we do not diagnose high-grade dysplasia)Rx: None furtherF-U: Surveillance
17 Desmoplasia, with or without inflammation The stroma of invasive colorectal carcinoma
18 Risk of metastasis from invasive carcinoma in pedunculated adenomas Depth of invasion % metssubmucosa 2muscularis 20pericolic adiposesource: accumulated literature
19 Haggitt levelssubmucosasubmucosaInvasive carcinoma in a pedunculated adenoma involves expanded submucosa
20 Cautery marks the resection margin No carcinoma in the cauterized tissue
21 Summary of this adenoma Endo: 2 cm pedunculated polypProc: PolypectomyMicro: Superficial invasive carcinoma in an adenoma, margin free No adverse prognostic featuresDx: SameRx: None furtherF-U: Surveillance
22 What are adverse prognostic features? Those features that have been associated with an adverse outcome after polypectomy, such as residual carcinoma at the polypectomy site and nodal metastases. These are likely to be indications for resection after the polypectomy
23 Adenomas with Carcinoma Indications for Resection, 3 studies St Marks* GIPS Clev ClinMargin involved <1mm <2mmCA Grade high high highLymphatics subjective yes noBlood vasc no yes no* both sessile and pedunc and must be removed in one piece.Geraghty, Williams, Talbot . Gut, 32 :Cooper, et al, Gastroenterol, 108: , 1995Volk, et al, Gastroenterol, 109: , 1995
24 1. Invasive carcinoma at the margin solid data Invasive carcinoma in a pedunculated adenoma: indications for colectomy1. Invasive carcinoma at the marginsolid data2. High-grade carcinoma: definition not clear;data limited3. Lymphatic invasion: data conflicting;overlaps with other indications
25 The best indicator for colectomy: Involvement of the margin Tumor in thecautery artifact at the marginThe best indicator for colectomy:Involvement of the margin
26 Carcinoma in the cautery artifact: margin involved A bias cut of the cauterized margin
27 2. High-grade carcinoma: definition not clear; data limited Invasive carcinoma in a pedunculated adenoma: indications for colectomy1. Invasive carcinoma at the marginsolid data2. High-grade carcinoma:definition not clear; data limited3. Lymphatic invasion: data conflicting;overlaps with other indications
29 3. Lymphatic invasion: data conflicting; Invasive carcinoma in a pedunculated adenoma: indications for colectomy1. Invasive carcinoma at the marginsolid data2. High-grade carcinoma: definition not clear;data limited3. Lymphatic invasion: data conflicting;overlaps with other indications. This is also a very subjective determination
30 The least reproducible indicator: lymphatic tumor thromboemboli
31 Unfavorable histopathologic factors associated with a high risk of node metastasis or local recurrence after endoscopic resection include1. poorly differentiated histology,2. vascular or lymphatic invasion,3. cancer at the resection margin4. incomplete endoscopic resection.ASGE guideline: endoscopy for colorectal cancerGASTROINTESTINAL ENDOSCOPY 61z:
32 Pedunculated adenomas with carcinoma confined to the submucosa can be considered to be adequately treated byendoscopic resection if removed completely and2. there are no unfavorable histologic features.
33 Surveillance after the endoscopic removal of a malignant polyp should consist of a follow-up colonoscopy within 3 to 6 months after resection.
39 Summary of this adenoma Endo: 7 cm sessile polypProc: BiopsyMicro: Adenoma with lots of villi,high-grade dysplasiaDx: AdenomaRx: It has to come out: possibilities:If proximal: local resectionIf rectal: ± mucosal resection
40 Treatment of GI Adenomas Adenomas must be removed in totoEndoscopic polypectomy, that is, gross total resection, is definitive, regardless if we see adenoma at a marginAfter biopsy of a large adenoma, removal is necessary, regardless of degree of dysplasia
41 What you need to say about a colonic adenoma in the pathology report Architecture: tubular, villous, tubulovillous, flat, serrated: Maybe villiHigh-grade dysplasia: MaybePseudoinvasion: NOAdenoma at the margin: NOThe word “adenoma” YES!Invasive carcinoma: YES!This is when we mention the margin.
42 In the 2006 guidelines for patients with adenomas, the most important determinants of interval to the next colonoscopy areNumber of adenomas: 3 or moreSize: if any polyp containing adenoma is at least 1 cm (polyp size, not adenoma size)High grade dysplasia (no published criteria)Villous features (no published criteria)Winawer et al: Gastroenterol, 130:1872, 2006
43 At the U of M, the gastroenterologists with whom we work do not find either high-grade dysplasia or villous features to be useful for determining surveillance intervals. They use size of the initial adenoma and the number of adenomas at the initial colonoscopy to make that decision.
44 There is no reason not to tell them what they want. Some gastroenterologists want to know the architecture, generally tubular, villous, or tubulovillous, and/or if high-grade dysplasia is presentThere is no reason not to tell them what they want.After all, we pathologists are a service organization!!!They don’t know that there are no hard criteria as to what is a villous component and what is HGD