TNM Staging: Colon and Rectum Tonya Brandenburg, MHA, CTR Kentucky Cancer Registry

Overview Colorectal Anatomy Common Terms Rules for Colorectal Cancer Changes in T,N,M Staging from AJCC 6th edition to 7th edition Elements of Staging: TX-T4, NX-N2b, and M0-M1b Stage Groups and Prognostic Factors Helpful Hints Colon/Rectal Examples

C18.4 C18.3 C18.5 C18.2 C18.6 C18.0 C18.0 C18.1 C21.--- C18.7 C18.1 Not Shown: Rectosigmoid C20.9 C19.9

Anatomy of the Colon and Rectum LEFT COLON Splenic Flexure (C18.5) Descending Colon (C18.6): 57-82 cm from anal verge Sigmoid Colon (C18.7):17-57 cm from verge Rectosigmoid (C19.9): 15- 17 cm from verge Rectum (C20.9): 4-16 cm from verge RIGHT COLON Appendix (C18.1) Cecum (C18.0): 150 cm from anal verge Ascending Colon (C18.2): 132-150 cm from verge Hepatic Flexure (C18.3) Transverse Colon (C18.4): 82-132 cm from verge

Colon and Rectum Anatomic subsites of the rectum Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer Anatomic subsites of the rectum

Common Terms . Circumferential margin – Any aspect of the colorectum that is not covered by a serosal layer and must be dissected from the retroperitoneum or subperitoneum to remove the viscus. Familial polyposis, familial adenomatous polyposis (FAP) a condition characterized by the development of many adenomatous polyps, often seen in several members of the same family Polyp, adenoma – These mean the same thing! Adenoma - A benign lesion composed of tubular or villous structures showing intraepithelial neoplasia

Non-Peritonealized Surface or Serosalized Area Some colon surfaces have no serosa at the exterior surface (around the hollow organ) The serosa acts as barrier for tumors that begin on inside surface of the colon and invade down into the mucosa and through the wall of the colon (the serosa) When there is no serosa – you lose a natural barrier that helps contain the colon cancer Non-Peritonealized Surfaces in Colon-Rectum: Rectum – no serosa in rectum below peritoneal reflection Descending Colon – no serosa covering posterior surfaces Ascending Colon – no serosa covering posterior surfaces

Non-Peritonealized Surface or Serosalized Area No Serosa Here Source: Clinical Anatomy for Medical Students, 5th Edition, Richard S. Snell. Little, Brown and Company, 1995.

Rules for Colon/Rectal Cancer Every individual site is a separate primary Use C18.8 for one lesion that overlaps two segments of colon where tumor point of origin cannot be determined Code C18.9 for multiple malignant adenomatous polyps or malignant adenomatous polyposis coli in various segments. Tumor size must be 998; histology = 8220/3 or 8221/3 Code C19.9 if one lesion overlaps the colon and rectum and point of origin cannot be determined If malignant polyp & frank malignancy in same segment of colon, code the frank malignancy

Changes in T,N,M Staging for Colon/Rectum from 6th edition to 7th edition Expansion of Stages II and III based on survival and relapse data that was not available for the 6th edition. Subdivision of T4, N1, and N2 M1 Also subdivided: M1a for a single metastatic site, M1b if multiple metastatic sites TNM scheme for carcinoma only; GIST and Neuroendocrine tumors now have their own chapters

Elements of Staging: TX, T0, and Tis TX: Tumor not seen on films T0: No evidence of primary tumor (use when you have metastasis that is consistent with colon/rectum primary, but no evidence of a primary tumor can be found) Tis: Tis is confined to glandular basement membrane or lamina propria with NO extent through muscularis mucosa Tumor in stalk of polyp is Tis if limited to lamina propria, but T1, T2, etc. if further invasion is noted The terms tumor confined to lamina propria including intramucosal, invades lamina propria, and confined to and not through the muscularis mucosae mean in-situ for AJCC staging, but not for behavior code and summary stage. Tumor confined to mucosa and invading lamina propria stage to localized disease in SS.

Elements of Staging: T1, T2, and T3 T1: Tumor invades the submucosa T2: Tumor invades the muscularis propria T3: Invasion into subserosa, or through subserosa into pericolorectal tissues

T1 tumor invades submucosal. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T1 tumor invades submucosal.

T2 tumor invades muscularis propria. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T2 tumor invades muscularis propria.

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T3 tumor invades through the muscularis propria into pericolorectal tissues.

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer Circumferential resection margin. T4a (left side) has perforated the visceral peritoneum. In contrast, T3; R2 (right side) shows macroscopic involvement of the circumferential resection margin of a non- peritonealized surface of the colorectum by tumor with gross disease remaining after surgical excision.

Elements of Staging: T4 (T4a and T4b) T4: Tumor directly invades other organs or structures, and/or perforates visceral peritoneum: T4a: tumor penetrates to the surface of the visceral peritoneum T4b: tumor directly invades or is adherent to other organs or structures

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T4a tumor penetrates to the surface of the visceral peritoneum. The tumor perforates (penetrates) visceral peritoneum, as illustrated here.

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T4a tumor perforates visceral peritoneum (shown with gross bowel perforation through the tumor).

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T4b tumor directly invades or is adherent to other organs or structures, as illustrated here with extension into an adjacent loop of small bowel.

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer T4b tumor directly invades or is adherent to other organs or structures (such as the sacrum shown here).

Compton, C. C. , Byrd, D. R. , et al. , Editors Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer The regional lymph nodes of the colon and rectum are colored by anatomic location, e.g., dark brown – right colon and cecum; blue – hepatic flexure to mid transverse colon; red – splenic flexure, left colon and sigmoid colon.

Lymphatic Drainage Each subsite of the colon has its own drainage system For all colon subsites, these include: Colic, NOS; Paracolic/ Pericolic. Right Colon Cecum and appendix: Cecal, anterior & posterior; ileocolic, right colic Ascending: Ileocolic, right colic, middle colic Hepatic Flexure: Right colic, middle colic Transverse: Middle colic Left Colon Splenic flexure: Middle colic & left colic; inferior mesenteric Descending colon: Left colic, sigmoid, inferior mesenteric Sigmoid: Sigmoidal, superior hemorrhoidal, superior rectal, inferior mesenteric

Satellite Nodules Satellite peritumoral nodule in the pericolorectal tissue of a primary carcinoma without histologic evidence of residual lymph node in the nodule may represent discontinuous spread, venous invasion with extravascular spread, or a totally replaced lymph node Replaced nodes should be counted separately as positive nodes in the N category

Elements of Staging: NX, N0, N1a, and N1b NX: Regional lymph nodes can’t be assessed N0: No regional lymph node metastasis N1: Metastasis in 1-3 regional lymph nodes N1a: Metastasis in 1 regional lymph node N1b: Metastasis in 2-3 regional lymph nodes

N1a is defined as metastasis in one regional lymph node. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer N1a is defined as metastasis in one regional lymph node.

N1b is defined as metastasis in 2 to 3 regional lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer N1b is defined as metastasis in 2 to 3 regional lymph nodes.

Elements of Staging: N1c N1c: Tumor deposits in the subserosa, mesentery, or non peritonealized pericolic or perirectal tissues WITHOUT regional nodal metastasis Foci of tumor found in the pericolic or perirectal fat or in adjacent mesentery (mesocolic fat) away from the leading edge of the tumor and showing no evidence of residual lymph node tissue are classified as N1c If tumor nodules are seen in lesions that would otherwise be classified as T1 or T2, then the primary tumor classification is not changed, but the nodule is recorded as an N1c positive node.

Elements of Staging: N2a and N2b N2: Metastasis in four or more regional lymph nodes N2a: Metastasis in 4-6 regional lymph nodes N2b: Metastasis is 7 or more regional lymph nodes

N2a is defined as metastasis in 4 to 6 regional lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer N2a is defined as metastasis in 4 to 6 regional lymph nodes.

N2b is defined as metastasis in seven or more regional lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer N2b is defined as metastasis in seven or more regional lymph nodes.

N2b showing nodal masses in more than 7 regional lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer N2b showing nodal masses in more than 7 regional lymph nodes.

Elements of Staging: MX, M0, and M1 MX: No longer exists in TNM Staging M0: No distant metastasis (Remember: not possible for pathologic staging) M1: Distant Metastasis M1a: Metastasis confined to one organ or site M1b: Metastasis in more than one organ/site or the peritoneum Common metastatic sites include liver*, lungs, seeding of other segments of the colon, small intestine, or peritoneum *Involvement of the liver is not considered distant metastasis if tumor has directly extended into the liver from the hepatic flexure or the right side of the transverse colon

Stage Groups

Prognostic Factors for Colon and Rectum Preoperative or pretreatment carcinoembryonic antigen (CEA) Tumor deposits Circumferential resection margin (CRM) Perineural invasion Microsatellite instability Tumor regression grade (with neoadjuvant therapy) KRAS gene analysis Note: None of these are required for staging. They are however, clinically significant

Hints for Colorectal Cancer Involvement of serosal surface is T4a Direct extension to certain organs (such as liver) from certain areas of colon (transverse, flexures, ascending, cecum) is T4b If T4 due to direct extent to abdominal organ & there is discontinuous metastasis there as well, M1a or M1b also applies Tumor that is adherent to other organs or structures grossly is classified T4b. If no tumor is present microscopically in the adhesion, then it is pT1-4a, depending upon depth of wall invasion.

Colon Case 1 Answers Topography: C18.5 Histology: 8263/3 This case is one primary per rule M2 Clinical Staging cT pTis cN cM Clinical Stage Group Pathological Staging pT 2 pN pM cM0 Pathologic Stage Group 1 SEER Summary Stage: 1 - Localized Rationale for staging choices The rule for carcinoma in-situ is pTis, N0, M0. Clinical stage would be 0. There is a technical advisory group composed of NPCR, SEER, CoC, and AJCC. They are trying to bridge the gap between what AJCC says to assign and uses to assign versus what an abstractor has to code in a registry. This isn’t final yet and may only be a solution for 2016, but this will get us through until the 8th edition where they may want to approach it differently, but most software doesn’t accommodate blanks. Tumor invading the superficial muscularis propria would be pT2, Lymph nodes negative = N0, No signs or symptoms of mets = M0

Colon Case 2 Answers Topography: C18.4 Histology: 8140/3 This case is one primary per rule M2 Clinical Staging cT X cN cM pM1a Clinical Stage Group IVA Pathological Staging pT 3 pN 2a pM 1b Pathologic Stage Group IVB SEER Summary Stage: 7 - Distant Rationale for staging choices Not enough info to assign clinical T or N, so TX, NX. M is based on supraclavicular ln bx which is pM1a. Clinical stage IVA. The critical thing to make something clinical or pathologic is not only the method obtained, but also the timing rules. For example if a scan is done after the first surgery, that is something clinic but is done after the first surgery. You can use a clinical M0 and M1 only if the criteria for pathological staging has been met. Tumor through muscularis propria and into pericolonic soft tissue = T3, 5 region ln involved = N2a, M1b bc of distant nodal mets and liver mets. Stage group IVB.