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1. TNM staging applies only to cases that have been microscopically
confirmed to be malignant.
2. The American College of Surgeons Commission on Cancer
has required that the TNM components and stage grouping be
recorded on the cancer registry abstract since 1991 for cancer
program approval. Effective with 1995 cases, the Commission
on Cancer will require that the physician stage the case.
3. In text, the components and descriptors (T,N,M,R,L,V,G)
should be shown as capital letters. The categories following
these should be shown as Arabic numerals, not as subscripts
(for example T1 N0 M0 rather than T1 N0 M0). Stage groupings
are represented as Roman numerals (I, II, III, IV) and subcategories
of stage groupings are represented as capital letters (IIB,
IIC, and so forth).
4. The preferred terminology to describe the values of T,
N, and M is "category." The phrase "T stage" or "N stage"
should not be used to avoid confusion with stage groupings,
which should be referred to as stages.
5. Standard TNM staging (clinical and pathological) is completed
only at initial diagnosis. (Other classifications, such as
retreatment or autopsy staging should be clearly identified
as such.) Information for clinical and pathologic staging
is gathered during the period prior to first course of therapy.
6. Clinical staging is based on information gained up to
the initial definitive treatment. Pathologic staging includes
clinical information and information obtained from pathologic
examination of resected primary and regional lymph nodes.
Always indicate the staging basis (chronology or time period)
of the staging.
7. Carcinomas are the only type of cancer that can be classified
as in situ (Tis). Only carcinomas have a basement membrane.
Sarcomas are never described as in situ.
8. Tis (in situ) cases determined either clinically or pathologically
are always classified as Stage 0, even when lymph nodes (N)
and distant metastases (M) are not assessed. According to
the definition of in situ, there can be no metastases.
9. If there is any evidence of invasion, nodal involvement,
or metastatic spread, the case is not in situ (Stage 0) even
if the pathology report so states. This is a common error
in staging cervical cancer where the pathology report so states
that the cancer is "in situ with microinvasion" such a case
would be considered invasive (at least T1).
10. Do not change the TNM classification and stage grouping
after they have been determined. The subsequent course of
the disease does not affect the initial extent of the disease.
Furthermore, information learned later did not affect the
treatment decision for the case. Therefore, it should not
be included in the TNM staging determination.
11. If there are lymph nodes involved by tumor, the N component
is at least N1.
12. If nodes, organs or adjacent tissues described in the
medical record are not specifically mentioned in the definitions
of the various categories, attempt to cross-reference the
term you have with those defined. If there is no match, assume
the site in question represents distant disease.
13. Do not mix staging classifications when analyzing survival.
Having additional information about some cases but not all
will skew the results.
14. Use the lowest common denominator appropriate to all
cases in a study. If all of the cases did not undergo surgical
resection, use the clinical staging to compare results.
15. As medical science progresses, classifications are revised.
It is important to know which revision of a staging system
is being used. Maintain a record in the registry procedure
manual stating when a staging system was revised or changed.
16. Each component may be individually defined as clinical
or pathological, such as pT3 cN0 cM0. When components with
mixed staging bases are stage grouped, the general clinical
and pathologic rules for classification apply. For example,
clinical M categories may be used for pathologic stage grouping,
but pathologic T categories should not be stage grouped with
clinically stage grouped cases.
17. The category X is used in each element to indicate that
there has been no assessment of that characteristic of the
tumor. It is important to differentiate the fact that no attempt
was made to assess the element from the fact that nothing
was found. For example, NX means that no diagnostic tools
were used to evaluate the status of lymph nodes, and N0 means
that no lymph node involvement was found by radiography or
other methods.
18. If a stage grouping contains the term "any," such as
Any T or Any N, the stage grouping is based on other elements
and it does not matter what that T or N is. Consequently,
even missing information including the X (not assessed) category
is acceptable for that element in that stage group. For example,
the chest CT scan for a lung cancer patient documents that
there is a large mass on the right side and contralateral
mediastinal lymph nodes involved. This case would be staged
as N3. Assuming that distant metastases are ruled out (M0),
it would not matter the size or location of the primary tumor,
because the N3 M0 combination is a stage group IIIB. If distant
metastases were present (M1), neither the size of the primary
nor the lymph node involvement would matter, because the case
is automatically stage group IV.
19. When stage grouping, if the combination of TNM elements
is not in the stage grouping table, the case should be considered
unstageable, or stage group 99.
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