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

2. 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

3. 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

4. Anatomy of the Colon and Rectum
LEFT COLON
Splenic Flexure (C18.5)
Descending Colon (C18.6): cm from anal verge
Sigmoid Colon (C18.7): cm from verge
Rectosigmoid (C19.9): 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): cm from verge Hepatic Flexure (C18.3) Transverse Colon (C18.4): cm from verge

5. 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, ©American Joint Committee on Cancer
Anatomic subsites of the rectum

6. 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

7. 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

8. 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.

9. 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

10. 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

11. 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.

12. 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

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

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

15. 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, ©American Joint Committee on Cancer
T3 tumor invades through the muscularis propria into pericolorectal tissues.

16. 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, ©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.

17. 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

18. 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, ©American Joint Committee on Cancer
T4a tumor penetrates to the surface of the visceral peritoneum. The tumor perforates (penetrates) visceral peritoneum, as illustrated here.

19. 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, ©American Joint Committee on Cancer
T4a tumor perforates visceral peritoneum (shown with gross bowel perforation through the tumor).

20. 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, ©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.

21. 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, ©American Joint Committee on Cancer
T4b tumor directly invades or is adherent to other organs or structures (such as the sacrum shown here).

22. 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, ©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.

23. 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

24. 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

25. 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

26. 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, ©American Joint Committee on Cancer
N1a is defined as metastasis in one regional lymph node.

27. 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, ©American Joint Committee on Cancer
N1b is defined as metastasis in 2 to 3 regional lymph nodes.

28. 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.

29. 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

30. 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, ©American Joint Committee on Cancer
N2a is defined as metastasis in 4 to 6 regional lymph nodes.

31. 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, ©American Joint Committee on Cancer
N2b is defined as metastasis in seven or more regional lymph nodes.

32. 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, ©American Joint Committee on Cancer
N2b showing nodal masses in more than 7 regional lymph nodes.

33. 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

34. Stage Groups

35. 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

36. 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.

37. 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

38. 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.