Download Cancer Staging - Cancer Care Nova Scotia

Many Hearts • Many Minds • One Goal
Volume 2 Number 3
May 2005
Cancer Staging
bt Maureen MacIntyre, Director, Surveillance and Epidemiology Unit, Cancer Care Nova Scotia and
Dr. Eva Grunfeld, Clinician Scientist and Director, Health Services and Outcomes Research, Cancer Care Nova Scotia
Understanding the extent of a cancer
at the time of diagnosis is perhaps
the single most important
determinant of the future care plan
and ultimately the patient’s
outcome. Commonly referred to as
‘staging’ the cancer, this concept of
determining disease extent
incorporates various clinical
parameters and applies a
standardized approach to assign a
stage value. Clinicians use this
knowledge to select the most
appropriate treatment plan for the
patient. It is important for all health
professionals involved in the care of
the cancer patient to understand
stage information, the important
role it plays in organizing patient
care, assessing treatment outcomes
and supporting cancer surveillance
and research.
This issue of In Practice is devoted to
cancer staging; the concept, its
application and a detailed outline of
the TNM stage system, which is
widely used across North America.
TNM examples are provided for the
most common cancers: breast, lung,
prostate and colorectal cancer. These
account for approximately 60% of
all new cancer diagnoses each year in
Nova Scotia (Saint Jacques et al,
2002). This information
complements an article in the
February 2005 issue of the Cancer
Care Nova Scotia (CCNS) newsletter
that provided an introduction to
staging intended to educate the
general public.
Survival of Female Breast Cancer Patients 1995-2002
by stage of disease at diagnosis followed to end of 2003
100
90
80
70
60
50
40
30
Local (early stage)
% Survival
Introduction
20
Regional (lymph node involvement)
10
Distant (metastatic spread)
0
1
2
3
4
5
Years Since Diagnosis
Overview
Staging describes the extent of a cancer at diagnosis based on: the tumour
size (T); the degree to which it has spread to the regional lymph nodes (N);
or metastasized to other parts of the body (M). In addition to this anatomic
approach, staging systems may also take into account other prognostic
factors such as histology, grade or serum tumour markers. Staging systems
must also have flexibility to adapt over time as new knowledge on prognostic
factors is ascertained (Hutchinson et al, 1997).
Stage systems provide a common language that physicians and other health
professionals can use to communicate prognosis and decide on treatment
options for a specific case. Long-term use and collection of stage data is
valuable for epidemiological and research purposes as similar types of cancer
can be grouped for analysis or selected for special studies. Recent breast
cancer survival for Nova Scotia is shown in the graph above where analysis
has included stage information to group cases.
Staging Systems
A variety of staging systems have been developed since
the early 1920’s, with many focused on a specific type of
cancer. The Dukes system for colorectal disease and Ann
Arbor classification for lymphomas may be familiar to
many cancer care providers. Perhaps the most widely
used stage system in the world is the TNM (i.e. Tumour,
Node, Metastases). The TNM system is now in its 6th
edition and applies to the majority of solid tumours.
TNM originated in France in the 1940’s and has been
supported and published since that time by the
International Union Against Cancer (UICC). The
United States based American Joint Committee on
Cancer (AJCC) has published TNM-based staging
material for 45 years (see AJCC Cancer Staging Manual
6th ed. 2002). Both the UICC and AJCC TNM
versions are now synchronized for both release date and
content.
Features of TNM
Anatomically based, the TNM system utilizes three main
elements when considering stage assessment. The use of
numerical subsets for each component indicates the
progressive extent of the cancer (AJCC Cancer Staging
Manual 6th ed. 2002). The following table outlines the
overall framework by element.
cancers that may have a different prognosis, an
additional letter may be used with the number to
subgroup (e.g. T2a versus T2b). Letter assignment is also
used in a progressive fashion. A final overall rule related
to use of TNM is that for it to be properly applied, cases
should be histologically confirmed.
Timing of TNM Assignment
TNM further allows the case to be staged at different
points in time relative to diagnosis.
• A clinical or cTNM is based on evidence before
primary treatment which may be gleaned from
physical examination, imaging, and in some cases,
even surgical exploration.
• A pathological or pTNM is again based on evidence
before treatment but including details gathered from
the surgery and subsequent pathological examination.
• It is also possible to stage a case at recurrence after a
disease-free interval at which time an ‘r’ precedes the
TNM designation. This may not be seen on a frequent
basis.
• Should the tumour only be found after death, the
TNM assignment would be preceded by an ‘a’,
signifying autopsy.
Stage Grouping
Tumour (T)
extent of the primary tumour
TX
Primary tumour cannot be evaluated
T0
No evidence of primary tumour
Tis
Carcinoma in situ (early cancer that has not
spread to neighbouring tissue)
T1, T2, T3, T4 Size and/or extent of the primary tumour
NX
N0
N1, N2, N3
MX
M0
M1
Regional Lymph Nodes (N)
Absence or presence and extent of regional
lymph node involvement
Regional lymph nodes cannot be evaluated
No regional lymph node involvement
(no cancer found in the lymph nodes)
Involvement of regional lymph nodes
(number and/or extent of spread)
Distant Metastasis (M)
Absence or presence of distant metastasis
Distant metastasis cannot be evaluated
No distant metastasis
(cancer has not spread to other parts
of the body)
Distant metastasis (cancer has spread to
distant parts of the body)
In cases where the numerical progression or assignment
is not sufficient to adequately differentiate a subset of
Considering the various numerical assignments that are
possible within the TNM framework, multiple
combinations of T, N and M are possible for any specific
disease. To simplify use of the TNM system and increase
its value as a communication tool, these combinations
have been arranged into a smaller number of stage
groupings, usually zero through four (i.e. 0, I, II, III,
IV). If justified, TNM may divide a group using a letter
(e.g. ‘a’ or ‘b’).
In many situations stage group may be the piece of
information that is most easily communicated to and
retained by the patient. Family physicians and other
health care professionals may see the full TNM stage or
just the stage group in documentation that is received
from the cancer specialist.
TNM Examples for Major Cancer Types
The following tables are specific to each of the major
cancer sites and provide the overall stage groupings along
with the applicable T, N and M combinations possible
within the disease. All tables are reproduced from the
AJCC Cancer Staging Manual, Sixth Edition, 2002.
Breast
Colorectal
Note – The comparable match between TNM, Dukes and
the Modified Astler Coller colorectal classification has been
added since these systems are still in use by some
practitioners.
Stage T Value
Group
N Value M Value Dukes Modified
AstlerColler
Stage Group
T Value
N Value
M Value
0
Tis
N0
M0
-
-
Stage 0
Tis
N0
M0
I
T1
N0
M0
A
A
Stage I
T1 or T1mic
N0
M0
T2
N0
M0
A
B1
Stage II A
T0
N1
M0
IIA
T3
N0
M0
B
B2
T1 or T1mic
N1
M0
IIB
T4
N0
M0
B
B3
T2
N0
M0
IIIA
T1-T2
N1
M0
C
C1
T2
N1
M0
IIIB
T3-T4
N1
M0
C
C2/C3
T3
N0
M0
IIIC
Any T
N2
M0
C
C1/C2/C3
T0
N2
M0
IV
Any T
Any N
M1
-
D
T1 or T1mic
N2
M0
T2
N2
M0
T3
N1
M0
T3
N2
M0
T4
N0
M0
T4
N1
M0
T4
N2
M0
Stage III C
Any T
N3
M0
Stage IV
Any T
Any N
M1
Stage II B
Stage III A
Stage III B
Prostate
TNM groupings for prostate also include Gleason score
(assigned by the pathologist) directly in the grouping
assignment. The AJCC uses this table for adenocarcinomas
and squamous carcinomas. Sarcomas and transitional cell
tumours are classified using other genito-urinary tables.
Stage Group
T Value
N Value
M Value
Gleason
Score
Stage I
T1a
N0
M0
G1
Stage II
T1a
N0
M0
G2, 3-4
T1b
N0
M0
Any G
T1c
N0
M0
Any G
T1
N0
M0
Any G
T2
N0
M0
Any G
Stage III
T3
N0
M0
Any G
Stage IV
T4
N0
M0
Any G
Any T
N1
M0
Any G
Any T
Any N
M1
Any G
Lung
Stage Group T Value N Value
M Value
Occult
TX
N0
MO
Stage 0
Tis
N0
MO
Stage IA
T1
N0
MO
Stage IB
T2
N0
MO
Stage IIA
T1
N1
MO
Stage IIB
T2
N1
MO
T3
N0
MO
T1
N2
MO
T2
N2
MO
T3
N1
MO
T3
N2
MO
Any T
N3
MO
T4
NX, N0, N1, N2 MO
Any T
Any N
Carcinoma
Stage IIIA
Stage IIIB
Stage IV
M1
What Lies Ahead
More information
Staging is critical to understanding an individual
patient’s cancer. It provides important insight
into prognosis and guides treatment decisions.
In addition, it offers tools for studying the
disease on a population level which, in turn,
assists with enhancing and improving treatment
and understanding of the disease.
The following websites may be helpful in
providing you with more information about
cancer staging or they may be useful for patients
and families who have questions.
As we learn more about cancer and the
prognosis of the disease, staging systems are
becoming more refined and, by necessity, more
complex. The AJCC has already started
preparations for the 7th Edition of TNM with
an expected release date of 2009. To improve
how health professionals in Nova Scotia can
benefit from the use of stage information, the
Nova Scotia Cancer Registry has begun work to
capture stage information on all newly
diagnosed cancers.
Canadian Cancer Society
www.cancer.ca
American Joint Committee on Cancer
www.cancerstaging.org
National Cancer Institute
www.nci.nih.gov
Surveillance Epidemiology End Results
Program
www.training.seer.cancer.gov/module_staging_cancer
In addition, Cancer Care Nova Scotia has
introduced the Oncology Interactive Education
Series (OIES), which is available at various
health facilities across the province. The
computer-based program includes information
for patients, families and health professionals. It
is available in CD format, is disease-specific and
includes explanations using TNM staging. For
more information about OIES, contact Sandra
Cook, project manager, by email at
[email protected]. or by phone at
902-473-3675.
CCNS also has a limited supply of an AJCC
five-card, quick reference pocket set of TNM
staging information for Breast, Lung, Prostate,
Colorectal and Cervix diagnoses. If you
would like a copy, please contact us by email
at [email protected] or by phone at
1-866-599-2267.
Cancer Care Nova Scotia is a
program of the Department of
Health. Its mandate is to
evaluate, coordinate and
strengthen the cancer system
in Nova Scotia.
Cancer Care Nova
Scotia works with and
supports professionals and
stakeholders in the health
care system to bring about
patient-centred change. Its
ultimate goal is to reduce the
burden of cancer on
individuals, families,
communities and the health
care system.
In Practice is a
supplement to Cancer Care
Nova Scotia’s newsletter. It is
written specifically for primary
care practitioners with
information that we hope will
make a difference in your
cancer practice.
Please contact Christine
Smith, Communications
Coordinator, Cancer Care
Nova Scotia, by phone at
902-473-2932 or by email at
[email protected]
with comments or
suggestions for future topics.
1278 Tower Road
5th Floor Bethune Building
Halifax, NS B3H 2Y9
Department of Health
References
1. Saint-Jacques N, MacIntyre M, Dewar R, Johnston G, Cancer Statistics in Nova
Scotia: A Focus on 1995-1999. Surveillance and Epidemiology Unit, Cancer Care Nova
Scotia; 2002
2. Hutchinson C, Roffers S, Fritz A, Cancer Registry Management Principles & Practice.
National Cancer Registrars Association, Iowa, Kendall/Hunt Publishing Co.; 1997
3. Greene F, Page D, Fleming I, Fritz A, Balch C, Haller D, Morrow M, AJCC Cancer
Staging Manual Sixth Edition. New York, Springer-Verlag; 2002