Rectal cancer (staging)
Updates to Article Attributes
Body
was changed:
Staging strongly influences the success of, and rate of local recurrence following rectal cancer resection. In rectal cancer, pre-treatment MRI is the evaluation of choice, guiding surgical and non-surgical management options.
TNM staging
See: TNM staging system for a general description.
Primary tumour staging (T)
- Tx: primary tumour cannot be assessed
- T0: no evidence of primary tumour
- Tis: carcinoma in situ: intraepithelial or invasion of lamina propria
- T1: tumour invades submucosa
- T2: tumour invades muscularis propria
-
T3: tumour invades through the muscularis propria into the subserosa or into non-peritonealised
peri-rectalperirectal tissues- T3a: tumour extends <1 mm beyond muscularis propria 4
- T3b: tumour extends 1-5 mm beyond muscularis propria 4
- T3c: tumour extends 5-15 mm beyond muscularis propria 4
- T3d: tumour extends 15 mm beyond muscularis propria 4
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T4: tumour invades directly into other organs or structures and/or perforates visceral peritoneum
- T4a: tumour penetrates to the surface of the visceral peritoneum
- T4b: tumour directly invades or is adherent to other organs or structures
Regional lymph nodes (N)
The size cut off for mesorectal nodes is usually taken at 5mm 6
- Nx: regional nodes not assessed
- N0: no regional lymph nodes
-
N1: metastasis in 1-3 regional (peri-rectal) lymph nodes
- N1a: metastasis in one regional lymph node
- N1b: metastasis 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: metastasis in 4 or more regional lymph nodes
- N2a: metastasis in 4-6 regional lymph nodes
- N2b: metastasis in 7 or more regional lymph nodes
Metastases
- Mx: cannot be assessed
- M0: no distant metastasis
-
M1: distant metastasis
- M1a: metastasis confined to one organ or site (for example, liver, lung, ovary, nonregional node)
- M1b: metastases in more than one organ/site or the peritoneum
Stage groupings
- stage 0: Tis N0 M0
- stage I: T1-2, N0 M0
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stage II
- IIa: T3, N0, M0
- IIb: T4a, N0, M0
- IIc: T4b, No, Mo
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stage III
- IIIa: T1-2, N1, M0
- IIIb: T3-4, N1, M0
- IIIc: T3-4b, N2, M0
- stage IV: any T, any N M1
Additional prognostic indicators
The following are significant prognostic indicators, and should be commented on when staging rectal cancer with MRI, alongside the TNM stage:
-
extramural venous invasion (EMVI)
- may be contiguous or non-contiguous
- imparts poor prognosis as a predictor of haematogenous spread
.
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circumferential resection margin (CRM)
- represented by the mesorectal fascia (MRF)
- CRM positive if either tumour, involved lymph node, or EMVI is within 1mm of the mesorectal fascia
.
See also
-<strong>T3:</strong> tumour invades through the muscularis propria into the subserosa or into non-peritonealised peri-rectal tissues<ul>- +<strong>T3:</strong> tumour invades through the muscularis propria into the subserosa or into non-peritonealised perirectal tissues<ul>
-</ul><ul><li>- +<li>
-</li></ul><ul>- +</li>
- +</ul><h6>Metastases</h6><ul>
-</ul><p><strong>Stage groupings</strong></p><ul>- +</ul><h5>Stage groupings</h5><ul>
-<li>imparts poor prognosis as a predictor of haematogenous spread.</li>- +<li>imparts poor prognosis as a predictor of haematogenous spread</li>
-<a title="Circumferential resection margin (CRM)" href="/articles/circumferential-resection-margin">circumferential resection margin (CRM)</a><ul>- +<a href="/articles/circumferential-resection-margin">circumferential resection margin (CRM)</a><ul>
-<li>CRM positive if either tumour, involved lymph node, or EMVI is within 1mm of the mesorectal fascia.</li>- +<li>CRM positive if either tumour, involved lymph node, or EMVI is within 1mm of the mesorectal fascia</li>