TNM classification of prostate tumours

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Management of locally advanced and metastatic prostate cancer > TNM classification of prostate tumours

Prostate

(ICD-0 C61)

Rules for classification

The classification applies only to adenocarcinomas. Transitional cell carcinoma of the prostate is classified as a urethral tumour (see UICC TNM Classification of Malignant Tumours, sixth edition1, page 203). There should be a histological confirmation of the disease.

The following are the procedures for assessing T, N and M categories:

  • T categories Physical examination, imaging, endoscopy, biopsy and biochemical tests
  • N categories Physical examination and imaging
  • M categories Physical examination, imaging, skeletal studies, and biochemical tests

Regional lymph nodes

The regional lymph nodes are the nodes of the true pelvis, which are essentially the pelvic nodes below the bifurcation of the common iliac arteries. Laterality does not affect the N classification.

TNM clinical classification*

T Primary tumour
TX Primary tumour cannot be assessed
T0 No evidence of primary tumour
T1 Clinically inapparent tumour not palpable or visible by imaging
T1a Tumour incident histological finding in 5% or less of tissue resected
T1b Tumour incident histological finding in more than 5% of tissue retracted
T1c Tumour identified by needle biopsy (eg because of elevated PSA)
T2 Tumour confined within prostate#
T2a Tumour involves one half of one lobe or less
T2b Tumour involves more than half of one lobe, but not both lobes
T2c Tumour involves both lobes
T3 Tumour extends through the prostatic capsule^
T3a Extracapsular extension (unilateral or bilateral)
T3b Tumour invades seminal vesicles(s)
T4 Tumour is fixed or invades adjacent structures other than seminal vesicles: bladder neck,

external sphincter, rectum, levator muscles, or pelvic wall

Notes:

# Tumour found in one or both lobes by needle boipsy, but not palpable or visible by imaging, is classified as T1c.
^ Invasion into the prostatic apex or into (but not beyond) the prostatic capsule is not classified as T3, but as T2.

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N Regional lymph nodes
NX Regional lymph nodes cannot be assessed
N0 No regional lymph nodes metastasis
N1 Regional lymph node metastasis

Notes:

Metastasis no larger than 0.2cm can be designated as pN1mi. (see Introduction, pN, page 10.)[1]
M Distant metastasis
MX Distant metastasis cannot be assessed
M0 No distant metastasis
M1 distant metastasis
M1a Non-regional lymph nodes(s)
M1b Bone(s)
M1c Other site(s)

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pTNM Pathological classification

The pT, pN, and pM categories correspond to the T, N, and M categories.

However, there is no pT1 category because there is insufficient tissue to assess the highest pT category.

G Histopathological grading

GX Grade cannot be assessed
G1 Well differentiated (slight anaplasia) (Gleason 2-4)
G2 Moderately differentiated (moderate anaplasia) (Gleason 5-6)
G3-4 Poorly differentiated/undifferentiated (marked anaplasia) (Gleason 7-10)

Stage grouping

Stage I T1a N0 M0 G1
Stage II T1a N0 M0 G2,3-4
T1b,c N0 M0 Any G
T1,T2 N0 M0 Any G
Stage III T3 N0 M0 Any G
Stage IV T4 N0 M09 Any G
Any T N1 M0 Any G
Any T Any N M1 Any G

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Summary

Prostate
T1 Not Palpable
:T1a <5%
:T1b >5%
:T1c Needle biopsy
T2 Confined within prostate
:T2a <half one lobe
:T2b >half one lobe
:T2c both lobes
T3 Through prostatic capsule
:T3a extracapsular
:T3b seminal vesicle(s)
T4 Fixed or invades adjacent structures: bladder neck, external sphincter, rectum, levator, muscles, pelvic wall
N1 Regional lymph node(s)
M1a Non-regional lymph node(s)
M1b Bone(s)
M1c Other site(s)

*Since these guidelines have been developed the UICC have published the seventh edition of TNM Classification of Malignant Tumours.[2] There is no material difference in the definition of the T-, N-, and M-categories, however, there are some differences in stage grouping and risk grouping. See the table below:

T1 Not palpable or visible

T1a     <5% or less

T1b    >5%

T1c    Detected by needle biopsy

 

T2 Confined within prostate

T2a   < half of one lobe

T2b   > half of one lobe

T2c    Both lobes

 

T3 Through prostate capsule

T3a   Extracapsular

T3b   Seminal vesicle(s)

 

T4 Fixed or invades adjacent structures

No change from 6th
STAGE GROUPING (ANATOMIC)       (UICC)

 

Stage I     T1, T2a    N0

Stage II    T2b-2c     N0

Stage III   T3             N0

Stage IV   T4            N0

                 Any T       N1

                 Any T      Any N       M1

 

 

 

Change from 6th
Grade was in 6th

 

PROGNOSTIC GROUPING

I      T1a – c    N0     PSA <10        Gle < 6

        T2a         N0     PSA <10         Gle < 6

 

IIA  T1 a – c   N0     PSA < 20        Gle 7

        T1 a – c   N0    PSA >10 <20  Gle <6

        T2a,b       N0    PSA >10 < 20 Gle < 7

 

 

 

If PSA or Gleason is missing, use whatever is available

IIB     T2c        N0      Any PSA     Any Gle

           T 1-2     N0      PSA >20     Any Gle

           T 1-2     N0      Any PSA    Gle > 8

 

III      T3a-c     N0      Any PSA    Any Gle

IV      T4          N0     Any PSA    Any Gle

          Any T    N1     Any PSA    Any Gle

          Any T   Any N M1 Any PSA Any Gle

 

If both missing, no prognostic grouping is possible


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References

  1. Sobin Lh, Wikkekind C. TNM Classification of Malignant Tumours.Sixth edition. UICC International Union Against Cancer. New York: Wiley-Liss 2002 Jan 1;184-187.
  2. Sobin LH, Gospodarowicz M, Wittekind C. TNM classification of Malignant Tumours. Seventh Edition. UICC International Union Against Cancer. New York: Wiley-Blackwell 2009 Jan 1.