V.6 AJCC TNM Staging

As the AJCC Cancer Staging Manual explains, the TNM system "is based on the premise that cancers of similar histology or site of origin share similar patterns of growth and extension. The size of the untreated cancer or tumor (T) increases progressively and at some point in time regional lymph node involvement (N) and finally, distant metastases (M) occur."

Coding Guidelines:

• TNM Stage is to be directly coded for cases with a date of diagnosis January 1, 2016 and forward.

• The TNM coding criteria are different for each primary site. Refer to the current AJCC Cancer Staging Manual to review specifics for the cancer site being abstracted in order to code TNM/Stage Group per AJCC criteria/rules.

• When a provider has assigned the stage, use the information as a guide for coding the stage, especially when information in the medical record is ambiguous or incomplete regarding the extent to which the tumor has spread.

• Sometimes the stage is stated incorrectly in the medical record due to a typographical, transcription, or similar error. If the stage recorded in one report is clearly contraindicated in another, query the provider or the registry’s medical consultant if possible. Do not code stage based on information that appears inaccurate.

• If the managing provider has not recorded the stage, registrars will code this item based on the best available information.

• If AJCC staging is used for a pediatric case, code the case using the appropriate AJCC values and site specific chapter rule.

• If a special pediatric staging system other than AJCC is used, code 88 to complete the AJCC TNM fields for the clinical and pathologic T, N, M and Stage Group.

• If a site/histology combination is not defined in the AJCC Manual, code 88 for clinical and pathologic T, N, and M as well as Stage Group.

TNM Categories:

• T* = Extent of the primary tumor (tumor size or extent of invasion)

• T0 , Tis, T1, T2, T3, T4

• N* = Regional lymph node involvement (absence or presence)

• N0, N1, N2, N3

• M* = Distant metastasis (absence or presence)

• M0, M1

*Note: Increasing number values indicate greater extent of disease

TNM Indicators/Prefixes:

• New indicators/prefixes of “c” and “p” were added to existing T, N & M categories.  Implementation and use in cancer registry software is effective in 2016 regardless of date of diagnosis.

• The addition of “c” and “p” prefixes allows assignment of T, N & M categories based on clinical and pathologic timeframes

• Necessary “p” values can be assigned in clinical stage classification to calculate clinical stage

Example: pTIS can be coded in clinical T data field

• Necessary “c” values can be assigned in pathologic stage classification to calculate pathologic stage

Example: cM0 can be coded in pathologic M data field

• Refer to each specific category section to review the tables of allowable values:

• Clinical T

• Clinical N

• Clinical M

• Pathologic T

• Pathologic N

• Pathologic M

 

 

 

<< Prev.       Next >>