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Rectal Cancer Treatment (PDQ®)

Stage Information for Rectal Cancer

Accurate staging provides crucial information about the location and size of the primary tumor in the rectum, and, if present, the size, number, and location of any metastases. Accurate initial staging can influence therapy by helping to determine the type of surgical intervention and the choice of neoadjuvant therapy to maximize the likelihood of resection with clear margins. In primary rectal cancer, pelvic imaging helps determine the following:[1-7]

  • The depth of tumor invasion.
  • The distance from the sphincter complex.
  • The potential for achieving negative circumferential (radial) margins.
  • The involvement of locoregional lymph nodes or adjacent organs.

Staging Evaluation

Clinical evaluation and staging procedures may include the following:

  • Digital-rectal examination (DRE): DRE and/or rectovaginal exam and rigid proctoscopy to determine if sphincter-saving surgery is possible.[1,2,5]
  • Colonoscopy: Complete colonoscopy to rule out cancers elsewhere in the bowel.[5]
  • Computed tomography (CT): Pan-body CT scan to rule out metastatic disease.[5]
  • Magnetic resonance imaging (MRI): MRI of the abdomen and pelvis to determine the depth of penetration and the potential for achieving negative circumferential (radial) margins and to identify locoregional nodal metastases and distant metastatic disease. MRI may be particularly helpful in determining sacral involvement in local recurrence.[1]
  • Endorectal ultrasound: Endorectal ultrasound with a rigid probe or a flexible scope for stenotic lesions to determine the depth of penetration and identify locoregional nodal metastases.[2,4]
  • Positron emission tomography (PET): PET to image distant metastatic disease.[1]
  • Carcinoembryonic antigen (CEA): Measurement of the serum CEA level for prognostic assessment and the determination of response to therapy.[6,7]

In the tumor (T) staging of rectal carcinoma, several studies indicate that the accuracy of endorectal ultrasound ranges from 80% to 95% compared with 65% to 75% for CT and 75% to 85% for MRI. The accuracy in determining metastatic nodal involvement by endorectal ultrasound is approximately 70% to 75% compared with 55% to 65% for CT and 60% to 70% for MRI.[2] In a meta-analysis of 84 studies, none of the three imaging modalities, including endorectal ultrasound, CT, and MRI, were found to be significantly superior to the others in staging nodal (N) status.[8] Endorectal ultrasound using a rigid probe may be similarly accurate in T and N staging when compared with endorectal ultrasound using a flexible scope; however, a technically difficult endorectal ultrasound may give an inconclusive or inaccurate result for both T stage and N stage. In this case, further assessment by MRI or flexible endorectal ultrasound may be considered.[4,9]

In patients with rectal cancer, the circumferential resection margin is an important pathological staging parameter. Measured in millimeters, it is defined as the retroperitoneal or peritoneal adventitial soft-tissue margin closest to the deepest penetration of tumor.[10]

TNM Classification System

AJCC stage groupings and TNM definitions

The American Joint Committee on Cancer (AJCC) has designated staging by tumor, node, and metastasis (TNM) classification to define rectal cancer.[11] The same classification is used for both clinical and pathologic staging.[11] Treatment decisions are made with reference to the TNM classification system, rather than the older Dukes or Modified Astler-Coller classification schema.

The AJCC staging system for rectal cancer does not apply to the following histologies:

Lymph node status

The AJCC and a National Cancer Institute-sponsored panel suggested that at least 10 to 14 lymph nodes be examined in radical colon and rectum resections in patients who did not receive neoadjuvant therapy. In cases in which tumor is resected for palliation or in patients who have received preoperative radiation therapy, fewer lymph nodes may be removed or present.[10-12] This takes into consideration that the number of lymph nodes examined is a reflection of both the aggressiveness of lymphovascular mesenteric dissection at the time of surgical resection and the pathologic identification of nodes in the specimen.

Retrospective studies, such as Intergroup trial INT-0089 [EST-2288], have demonstrated that the number of lymph nodes examined during colon and rectal surgery may be associated with patient outcome.[13-16]

A new tumor-metastasis staging strategy for node-positive rectal cancer has been proposed.[17]

Table 1. Definitions of TNM Stage 0
StageTNMa,bDukescMACdDescriptionIllustration
T = primary tumor; N = regional lymph nodes; M = distant metastasis.
Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
The explanations for superscripts a–g are at the end of Table 5.
0Tis, N0, M0Tis = Carcinoma in situ: intraepithelial or invasion of lamina propria.e
Stage 0 colon/rectal carcinoma in situ; shows a cross-section of the colon/rectum. An inset shows the layers of the colon/rectum wall with abnormal cells in the mucosa layer. Also shown are the submucosa, muscle layers, serosa, a blood vessel, and lymph nodes.
N0 = No regional lymph node metastasis.
M0 = No distant metastasis.
Table 2. Definitions of TNM Stage I
StageTNMa,bDukescMACdDescriptionIllustration
T = primary tumor; N = regional lymph nodes; M = distant metastasis.
Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
The explanations for superscripts a–g are at the end of Table 5.
IT1, N0, M0AAT1 = Tumor invades submucosa.
Stage I colorectal cancer; shows a cross-section of the colon/rectum. An inset shows the layers of the colon/rectum wall with cancer in the mucosa, submucosa, and muscle layers. Also shown are the serosa, a blood vessel, and lymph nodes.
N0 = No regional lymph node metastasis.
M0 = No distant metastasis.
T2, N0, M0AB1T2 = Tumor invades muscularis propria.
N0 = No regional lymph node metastasis.
M0 = No distant metastasis.
Table 3. Definitions of TNM Stage II
StageTNMa,bDukescMACdDescriptionIllustration
T = primary tumor; N = regional lymph nodes; M = distant metastasis.
Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
The explanations for superscripts a–g are at the end of Table 5.
IIAT3, N0, M0BB2T3 = Tumor invades through the muscularis propria into pericolorectal tissues.
Stage II colorectal cancer; shows a cross-section of the colon/rectum and a three-panel inset. Each panel shows the layers of the colon/rectum wall: mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. First panel shows stage IIA with cancer in the mucosa, submucosa, muscle layers, and serosa. Second panel shows stage IIB with cancer in all layers and spreading through the serosa. Third panel shows stage IIC with cancer spreading to nearby organs.
N0 = No regional lymph node metastasis.
M0 = No distant metastasis.
IIBT4a, N0, M0BB2T4a = Tumor penetrates to the surface of the visceral peritoneum.f
N0 = No regional lymph node metastasis.
M0 = No distant metastasis.
IICT4b, N0, M0BB3T4b = Tumor directly invades or is adherent to other organs or structures.f,g
N0 = No regional lymph node metastasis.
M0 = No distant metastasis.
Table 4. Definitions of TNM Stage III
StageTNMa,bDukescMACdDescriptionIllustration
T = primary tumor; N = regional lymph nodes; M = distant metastasis.
Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
The explanations for superscripts a–g are at the end of Table 5.
IIIAT1–T2, N1/N1c, M0CC1T1 = Tumor invades submucosa.
Stage IIIA colorectal cancer; shows a cross-section of the colon/rectum and a two-panel inset. Each panel shows the layers of the colon/rectum wall: mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. First panel shows cancer in the mucosa, submucosa, muscle layers, and 2 lymph nodes. Second panel shows cancer in the mucosa, submucosa, and 5 lymph nodes.
T2 = Tumor invades muscularis propria.
N1 = Metastases in 1–3 regional lymph nodes.
N1c = Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized pericolic or perirectal tissues without regional nodal metastasis.
M0 = No distant metastasis.
T1, N2a, M0CC1T1 = Tumor invades submucosa.
N2a = Metastases in 4–6 regional lymph nodes.
M0 = No distant metastasis.
IIIBT3–T4a, N1/N1c, M0CC2T3 = Tumor invades through the muscularis propria into pericolorectal tissues.
Stage IIIB colorectal cancer; shows a cross-section of the colon/rectum and a two-panel inset. Each panel shows the layers of the colon/rectum wall: mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. First panel shows cancer in all layers, spreading through the serosa, and in 3 lymph nodes. Second panel shows cancer in all layers and in 5 lymph nodes. Third panel shows cancer in the mucosa, submucosa, muscle layers, and 7 lymph nodes.
T4a = Tumor penetrates to the surface of the visceral peritoneum.f
N1 = Metastases in 1–3 regional lymph nodes.
N1c = Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized pericolic or perirectal tissues without regional nodal metastasis.
M0 = No distant metastasis.
T2–T3, N2a, M0CC1/C2T2 = Tumor invades muscularis propria.
T3 = Tumor invades through the muscularis propria into pericolorectal tissues.
N2a = Metastases in 4–6 regional lymph nodes.
M0 = No distant metastasis.
T1–T2, N2b, M0CC1T1 = Tumor invades submucosa.
T2 = Tumor invades muscularis propria.
N2b = Metastases in ≥7 regional lymph nodes.
M0 = No distant metastasis.
IIICT4a, N2a, M0CC2T4a = Tumor penetrates to the surface of the visceral peritoneum.f
Stage IIIC colorectal cancer; shows a cross-section of the colon/rectum wall and a three-panel inset. Each panel shows the layers of the colon/rectum wall: mucosa, submucosa, muscle layers, and serosa. Also shown are a blood vessel and lymph nodes. First panel shows cancer in all layers, spreading through the serosa, and in 4 lymph nodes. Second panel shows cancer in all layers and in 7 lymph nodes. Third panel shows cancer in all layers, spreading through the serosa, in 2 lymph nodes, and spreading to nearby organs.
N2a = Metastases in 4–6 regional lymph nodes.
M0 = No distant metastasis.
T3–T4a, N2b, M0CC2T3 = Tumor invades through the muscularis propria into pericolorectal tissues.
T4a = Tumor penetrates to the surface of the visceral peritoneum.f
N2b = Metastases in ≥7 regional lymph nodes.
M0 = No distant metastasis.
T4b, N1–N2, M0CC3T4b = Tumor directly invades or is adherent to other organs or structures.f,g
N1 = Metastases in 1–3 regional lymph nodes.
N2 = Metastases in ≥4 regional lymph nodes.
M0 = No distant metastasis.
Table 5. Definitions of TNM Stage IV
StageTNMa,bDukescMACdDescriptionIllustration
T = primary tumor; N = regional lymph nodes; M = distant metastasis.
Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
acTNM is the clinical classification, and pTNM is the pathologic classification. The y prefix is used for those cancers that are classified after neoadjuvant pretreatment (e.g., ypTNM). Patients who have a complete pathologic response (ypT0, N0, cM0) may be similar to stage group 0 or I. The r prefix is to be used for those cancers that have recurred after a disease-free interval (rTNM).
bA satellite peritumoral nodule in the pericolorectal adipose tissue of a primary carcinoma without histologic evidence of residual lymph node in the nodule may represent discontinuous spread, venous invasion with extravascular spread (V1/2), or a totally replaced lymph node (N1/2). Replaced nodes should be counted separately as positive nodes in the N category, whereas discontinuous spread or venous invasion should be classified and counted in the site-specific factor category Tumor Deposits.
cDukes B is a composite of better (T3, N0, M0) and worse (T4, N0, M0) prognostic groups, as is Dukes C (any T, N1, M0 and any T, N2, M0).
dMAC is the modified Astler-Coller classification.
eTis includes cancer cells confined within the glandular basement membrane (intraepithelial) or mucosal lamina propria (intramucosal) with no extension through the muscularis mucosae into the submucosa.
fDirect invasion in T4 includes invasion of other organs or other segments of the colorectum as a result of direct extension through the serosa, as confirmed on microscopic examination (e.g., invasion of the sigmoid colon by a carcinoma of the cecum) or, for cancers in a retroperitoneal or subperitoneal location, direct invasion of other organs or structures by virtue of extension beyond the muscularis propria (i.e., respectively, a tumor on the posterior wall of the descending colon invading the left kidney or lateral abdominal wall; or a mid or distal rectal cancer with invasion of prostate, seminal vesicles, cervix, or vagina).
gTumor that is adherent to other organs or structures, grossly, is classified cT4b. However, if no tumor is present in the adhesion, microscopically, the classification should be pT1–4a depending on the anatomical depth of wall invasion. The V and L classifications should be used to identify the presence or absence of vascular or lymphatic invasion whereas the PN site-specific factor should be used for perineural invasion.
IVAAny T, Any N, M1aTX = Primary tumor cannot be assessed.
Stage IV rectal cancer; drawing shows other parts of the body where rectal cancer may spread, including lymph nodes, lung, liver, abdominal wall, and ovary. Inset shows cancer spreading through the blood and lymph nodes to other parts of the body.
T0 = No evidence of primary tumor.
Tis = Carcinoma in situ: intraepithelial or invasion of lamina propria.e
T1 = Tumor invades submucosa.
T2 = Tumor invades muscularis propria.
T3 = Tumor invades through the muscularis propria into pericolorectal tissues.
T4a = Tumor penetrates to the surface of the visceral peritoneum.f
T4b = Tumor directly invades or is adherent to other organs or structures.f,g
NX = Regional lymph nodes cannot be assessed.
N0 = No regional lymph node metastasis.
N1 = Metastases in 1–3 regional lymph nodes.
N1a = Metastasis in 1 regional lymph node.
N1b = Metastases in 2–3 regional lymph nodes.
N1c = Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized pericolic or perirectal tissues without regional nodal metastasis.
N2 = Metastases in ≥4 regional lymph nodes.
N2a = Metastases in 4–6 regional lymph nodes.
N2b = Metastases in ≥7 regional lymph nodes.
M1a = Metastasis confined to 1 organ or site (e.g., liver, lung, ovary, nonregional node).
IVBAny T, Any N, M1bTX = Primary tumor cannot be assessed.
T0 = No evidence of primary tumor.
Tis = Carcinoma in situ: intraepithelial or invasion of lamina propria.e
T1 = Tumor invades submucosa.
T2 = Tumor invades muscularis propria.
T3 = Tumor invades through the muscularis propria into pericolorectal tissues.
T4a = Tumor penetrates to the surface of the visceral peritoneum.f
T4b = Tumor directly invades or is adherent to other organs or structures.f,g
NX = Regional lymph nodes cannot be assessed.
N0 = No regional lymph node metastasis.
N1 = Metastases in 1–3 regional lymph nodes.
N1a = Metastasis in 1 regional lymph node.
N1b = Metastases in 2–3 regional lymph nodes.
N1c = Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized pericolic or perirectal tissues without regional nodal metastasis.
N2 = Metastases in ≥4 regional lymph nodes.
N2a = Metastases in 4–6 regional lymph nodes.
N2b = Metastases in ≥7 regional lymph nodes.
M1b = Metastases in >1 organ/site or the peritoneum.

References

  1. Schmidt CR, Gollub MJ, Weiser MR: Contemporary imaging for colorectal cancer. Surg Oncol Clin N Am 16 (2): 369-88, 2007. [PUBMED Abstract]
  2. Siddiqui AA, Fayiga Y, Huerta S: The role of endoscopic ultrasound in the evaluation of rectal cancer. Int Semin Surg Oncol 3: 36, 2006. [PUBMED Abstract]
  3. Søreide K: Molecular testing for microsatellite instability and DNA mismatch repair defects in hereditary and sporadic colorectal cancers--ready for prime time? Tumour Biol 28 (5): 290-300, 2007. [PUBMED Abstract]
  4. Zammit M, Jenkins JT, Urie A, et al.: A technically difficult endorectal ultrasound is more likely to be inaccurate. Colorectal Dis 7 (5): 486-91, 2005. [PUBMED Abstract]
  5. Libutti SK, Willett CG, Saltz LB: Cancer of the rectum. In: DeVita VT Jr, Lawrence TS, Rosenberg SA: Cancer: Principles and Practice of Oncology. 9th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2011, pp 1127-41.
  6. Goldstein MJ, Mitchell EP: Carcinoembryonic antigen in the staging and follow-up of patients with colorectal cancer. Cancer Invest 23 (4): 338-51, 2005. [PUBMED Abstract]
  7. Das P, Skibber JM, Rodriguez-Bigas MA, et al.: Predictors of tumor response and downstaging in patients who receive preoperative chemoradiation for rectal cancer. Cancer 109 (9): 1750-5, 2007. [PUBMED Abstract]
  8. Lahaye MJ, Engelen SM, Nelemans PJ, et al.: Imaging for predicting the risk factors--the circumferential resection margin and nodal disease--of local recurrence in rectal cancer: a meta-analysis. Semin Ultrasound CT MR 26 (4): 259-68, 2005. [PUBMED Abstract]
  9. Balch GC, De Meo A, Guillem JG: Modern management of rectal cancer: a 2006 update. World J Gastroenterol 12 (20): 3186-95, 2006. [PUBMED Abstract]
  10. Compton CC, Greene FL: The staging of colorectal cancer: 2004 and beyond. CA Cancer J Clin 54 (6): 295-308, 2004 Nov-Dec. [PUBMED Abstract]
  11. Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-64.
  12. Nelson H, Petrelli N, Carlin A, et al.: Guidelines 2000 for colon and rectal cancer surgery. J Natl Cancer Inst 93 (8): 583-96, 2001. [PUBMED Abstract]
  13. Swanson RS, Compton CC, Stewart AK, et al.: The prognosis of T3N0 colon cancer is dependent on the number of lymph nodes examined. Ann Surg Oncol 10 (1): 65-71, 2003 Jan-Feb. [PUBMED Abstract]
  14. Le Voyer TE, Sigurdson ER, Hanlon AL, et al.: Colon cancer survival is associated with increasing number of lymph nodes analyzed: a secondary survey of intergroup trial INT-0089. J Clin Oncol 21 (15): 2912-9, 2003. [PUBMED Abstract]
  15. Prandi M, Lionetto R, Bini A, et al.: Prognostic evaluation of stage B colon cancer patients is improved by an adequate lymphadenectomy: results of a secondary analysis of a large scale adjuvant trial. Ann Surg 235 (4): 458-63, 2002. [PUBMED Abstract]
  16. Tepper JE, O'Connell MJ, Niedzwiecki D, et al.: Impact of number of nodes retrieved on outcome in patients with rectal cancer. J Clin Oncol 19 (1): 157-63, 2001. [PUBMED Abstract]
  17. Greene FL, Stewart AK, Norton HJ: New tumor-node-metastasis staging strategy for node-positive (stage III) rectal cancer: an analysis. J Clin Oncol 22 (10): 1778-84, 2004. [PUBMED Abstract]
  • Updated: December 16, 2014