• Staging is the clinical or pathological assessment of the extent of tumour spread
• Clinical staging is a preoperative assessment
• It is based on clinical, radiological and operative information
• Used to determine treatment offered to the patient
• Pathological staging is a postoperative assessment
• Provides useful prognostic information
• Allows decisions to be made regarding adjuvant therapy
• Allows comparison of treatment outcomes between different centres

Staging systems

• The ideal staging system should be:
  • Easy to use and remember
  • Reproducible - not subject to inter or intra-observer variation
  • Based on prognostically important pathological factors

TNM system

• Based on anatomical extent of spread
  • T refers to the extent of primary tumour
  • N refers to the extent of nodal metastases
  • M refers to the presence or absence of distant metastases
• Two classifications are described for each site
  • Clinical classification (TNM)
  • Pathological classification (pTNM)

• The TNM system is generally accepted
• Does not recorded all factors (e.g. grade, contiguous organ involvement) that is prognostically important

Dukes staging of colorectal cancer

• First published in 1932 for rectal cancers
• Now used for all rectal and colonic cancers

• Duke's A - spread into submucosa but not through muscle
• Duke's B - spread through muscle but nodes negative
• Duke's C - lymph node metastases present
• Often divided into C1 and C2 dependent on the involvement of the highest lymph node
• Advantages of the Dukes classification are that it
• Is simple and reproducible
• Accurately reflects prognosis
• Accepted nationally and internationally

Bibliography

Sobin L H.  TNM:  principles, history and relation to other prognostic factors.  Cancer 2001;  91 (Suppl 8):  S1589-1592.

Yarbro J W,  Page D L,  Fielding L P,  Partridge E E,  Murphy G P.  American Joint Committee on Cancer prognostic factors consensus conference.  Cancer 1999;  86:  2436-2446.