Prostate Cancer Grading & Staging Systems

 The clinical staging of prostate cancer uses pretreatment parameters to predict the extent of disease, for assessment of prognosis and to assist in decisions regarding appropriate treatment.  Pretreatment information used to predict disease extent in men with prostate cancer include DRE (T stage), PSA and its derivatives, prostate cancer features on needle biopsy, and in recurrent disease radiologic imaging.  

  • Pathologic stage is determined after prostate removal and involves histologic analysis of the prostate, seminal vesicles, and pelvic lymph nodes if lymphadenectomy is performed.
  • Pathologic staging more accurately estimates disease burden and is more useful than clinical staging for outcome prediction.  The most important pathologic criteria that predict prognosis after radical prostatectomy are tumor grade, surgical margin status, extracapsular disease, seminal vesicle invasion, and pelvic lymph node involvement.
  • Biochemical recurrence-free survival and cancer-specific survival are both inversely related to the pathologic stage of disease.

GLEASON GRADE

  • This is a system based on the degree of glandular differentiation and growth pattern. Five patterns have been described.
  • A Gleason "score" is given for each tumor, representing the sum of the two most common patterns displayed. The scores range from 2 to 10 and have some prognostic predictive value at the very low or very high ranges.
  • This is the most commonly used grading system for prostate adenocarcinoma

DEFINITIONS:

 
Anatomic Stage / Prognostic Groups
 Group  T  N M PSA  Gleason
I


 T1a-c  NO  MO  PSA < 10  Gleason ≤ 6
 T2a  NO  MO  PSA < 10  Gleason ≤ 6
 T1-2a  NO  MO  PSA X  Gleason X
IIA



 
 T1a-c  NO  MO  PSA<20  Gleason 7
 T1a-c  NO  MO  PSA≥10<20  Gleason ≤ 6
 T2a  NO  MO  PSA≥10<20  Gleason ≤6
 T2a  NO  MO  PSA<20  Gleason 7
 T2b  NO  MO  PSA<20  Gleason ≤7
 T2b  NO  MO  PSA X  Gleason X
IIB


 T2c  NO  MO  Any PSA  Any Gleason
 T1-2  NO  MO  PSA ≥ 20  Any Gleason
 T1-2  NO  MO  Any PSA  Gleason ≥8
III  T3a-b  NO  MO  Any PSA  Any Gleason
IV

 T4  NO  MO  Any PSA  Any Gleason
 Any T  N1  MO  Any PSA  Any Gleason
 Any T  Any N  M1  Any PSA  Any Gleason
 
Prostate Cancer Primary Tumor [T] TNM Clinical Staging System AJCC 2010
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
T1 Clinically inapparent tumor neither palpable nor visible by imaging
T1a Normal DRE; incidental tumor ≤ 5% of total surgical specimen in histological finding
T1b Normal DRE: incidental tumor > 5% of specimen, any grade, or < 5% of resected specimen 
T1c Normal DRE; tumor identified by prostate needle biopsy (e.g. elevated PSA)
T2 Tumor confined to the prostate [1]
T2a Organ-confined limited to one half of one lobe of the prostate or less
T2b Organ-confined; more than one half of a lobe but not both lobes
T2c Tumor involves both lobes
T3 Tumor extends through the prostate capsule [2]
T3a Extracapsular extension (unilateral or bilateral)
T3b Tumor invades seminal vesicle(s)
T4 Tumor is fixed or invades adjacent structures other than seminal vesicles (e.g., bladder, rectum)

Notes:
[1]  Tumor found in one or both lobes by needle biopsy, but not palpable or reliably visiblle by imaging, is classified as T1c.
[2]  Invasion into the prostatic apex or into (but not beyond) the prostatic capsule is classified not as T3, but as T2.

Regional Lymph Nodes (N) Clinical 
NX Regional lymph nodes were not assessed
N0 No regional lymph node metastasis
N1 Metastasis in regional lymph node(s)
          
  Regional Lymph Node (N) Pathologic
 pNX  Regional nodes not sampled
 pN0  No positive regional nodes
 pN1  Metastases in regional node(s)

 

Distant Metastasis (M) [5]
M0 No distant metastasis
M1 Distant metastasis 
M1a Nonregional lymph node(s) metastasis 
M1b Bone(s) metastasis 
M1c Other metastatic site(s) with or without bone disease

Notes:

[5] When more than one site of metastasis is present, the most advanced category is used. pM1c is most advanced.

          
Grade
G1 Well differentiated (Gleason score 2 -4)
G2 Moderately differentiated (Gleason score 5-6)
G3-4 Poorly differentiated or undifferentiated (marked anaplasia) (Gleason score 7-10)

 

Clinical Stage Grouping
G1 G2-4 Any Grade
T1a T1bc T2 T3 T4
N0 I II II II III IV
N1 IV IV IV IV IV IV
M1 IV IV IV IV IV IV
t4prostate
          
Pathologic Stage [3]
pT2 Tumor confined to the prostate
T2a Unilateral, involving one half of one lobe or less
T2b Unilateral, more than one half of a lobe but not both
T2c Tumor involves both lobes
T3 Extraprostatic extension [4]
T3a Extracapsular extension (unilateral or bilateral)
T3b Seminal vesicle invasion
T4 Invasion of bladder or rectum

Notes;

[3] There is no pathologic T1 description
[4] Positive margin of resection denoted by an R1 descriptor (residual microscopic disease).

 

MOLECULAR STAGING OF PROSTATE CANCER

The recent regulatory approval of the semiautomated CellSearch system (Veridex, Raritan, NJ) for monitoring prostate cancer, has led to investigation to determine whether circulating tumor cells have a role in the staging of early disease.  

 


REFERENCES

  • American Joint Committee on Cancer (2010). Prostate. In AJCC Cancer Staging Manual, 7th ed.  (Part IX. Genitourinary Sites - Prostate) Edge, S.B.; Byrd, D.R.; Compton, C.C.; Fritz, A.G.; Greene, F.L.; Trotti, A. (Eds.)

  • Davis et al, 2008. Davis JW, Nakanishi H, Kumar VS, et al: Circulating tumor cells in peripheral blood samples from patients with increased serum prostate specific antigen: initial results in early prostate cancer. J Urol  2008; 179(6):2187-2191.

  • Helo et al, 2009. Helo P, Cronin AM, Danila DC, et al: Circulating prostate tumor cells detected by reverse transcription-pcr in men with localized or castration-refractory prostate cancer: concordance with CellSearch assay and association with bone metastases and with survival. Clin Chem  2009; 55(4):765-773.

  • Lin EH, Lozano R and Karp DD. Color-Matrix Cancer Staging and Treatment Handbook, 3rd edition. The University of Texas MD Anderson Cancer Center, 2004, p. 28.

  • Pound et al, 1997. Pound CR, Partin AW, Epstein JI, et al: Prostate-specific antigen after anatomic radical retropubic prostatectomy. Patterns of recurrence and cancer control. Urol Clin North Am  1997; 24(2):395-406.