In preparation for the 8th edition of the TNM
classification for lung cancer the IASLC and their statistical partners at
Cancer Research And Biostatistics (CRAB) established a new data base (5). This
collected data on another 94,708 cases of lung cancer diagnosed between 1999
and 2010, treated by all modalities of care, donated by 35 institutions in 16
countries around the globe. After exclusions 77,156 remained for analysis,
70,967 cases of non-small cell lung cancer (NSCLC) and 6,189 cases of
small-cell lung cancer (SCLC).
Analysis of the cases of NSCLC has allowed proposals to be formulated for revisions to the T, N and M descriptors and categories, and the resultant TNM Stage groupings.
The proposals the T descriptors have been published . Size continues to be an important determinant and will become a descriptor for all of the T categories from T1 to T4 inclusive. The T size cut points of the 7th edition will be retained, vis 2, 3, 5 and 7 cms, and new cut points at 1 and 4 cms have been proposed. As a result new T categories have been created and others have been reassigned. In addition tumours invading the diaphragm have been reclassified as T4 and tumours extending within 2 cms of the carina, but without invasion of the carina itself, or those tumours associated with collapse or consolidation of the whole lung have been down-staged to T2. The resultant T categories are shown in Table along with the proposals for N and M categories.
It is recommended that the N categories of the 7th edition be retained. Exploratory analysis of surgically resected, pathologically classified cases has suggested that the prognostic significance of the anatomic location of involved nodes can be augmented if combined with the number of involved nodes in N1 and N2 locations and the use of this sub-classification has been proposed for testing in the 8th edition .
The proposals for the M classification retain the existing category of M1a . The category of M1b has been re-assigned to describe a form of extremely limited "oligometastatic" cases in which there is a single metastatic deposit in one distant organ. A new category of M1c has therefore emerged to describe the commoner situation in which there are multiple metastases in one or more distant sites.
The resultant T N M Stage groupings, derived from recursive partitioning and amalgamation analyses were refined by the committee by study of their statistical features and clinical relevance and are shown in Table. As in the 7th edition the IASLC Staging and Prognostic Factors Committee have attempted to resolve some issues in which data is limited by review of the literature and by consensus. These include how one should assess tumour size in the small tumours of mixed density increasing common when evaluation CT screen detected cancers. The committee's recommendation is that it should be the solid element on imaging, or the invasive component on pathological examination which should be measured to determine T size . In a series of articles the committee has given advice as to how one should classify the various scenarios in which multiple tumours are discovered in the lung(s) .
The IASLC has submitted all of these proposals to the Union for International Cancer Control (UICC) and the American Joint Committee on Cancer (AJCC), the 2 bodies that regulate the TNM classification for all tumour sites globally. The 8th edition is due to be published this Autumn. The IASLC will have extensive educational products available to attendees at the 17th World Conference on Lung Cancer, to be held in Vienna from the 4th to the 7th of December 2016.
Analysis of the cases of NSCLC has allowed proposals to be formulated for revisions to the T, N and M descriptors and categories, and the resultant TNM Stage groupings.
The proposals the T descriptors have been published . Size continues to be an important determinant and will become a descriptor for all of the T categories from T1 to T4 inclusive. The T size cut points of the 7th edition will be retained, vis 2, 3, 5 and 7 cms, and new cut points at 1 and 4 cms have been proposed. As a result new T categories have been created and others have been reassigned. In addition tumours invading the diaphragm have been reclassified as T4 and tumours extending within 2 cms of the carina, but without invasion of the carina itself, or those tumours associated with collapse or consolidation of the whole lung have been down-staged to T2. The resultant T categories are shown in Table along with the proposals for N and M categories.
It is recommended that the N categories of the 7th edition be retained. Exploratory analysis of surgically resected, pathologically classified cases has suggested that the prognostic significance of the anatomic location of involved nodes can be augmented if combined with the number of involved nodes in N1 and N2 locations and the use of this sub-classification has been proposed for testing in the 8th edition .
The proposals for the M classification retain the existing category of M1a . The category of M1b has been re-assigned to describe a form of extremely limited "oligometastatic" cases in which there is a single metastatic deposit in one distant organ. A new category of M1c has therefore emerged to describe the commoner situation in which there are multiple metastases in one or more distant sites.
The resultant T N M Stage groupings, derived from recursive partitioning and amalgamation analyses were refined by the committee by study of their statistical features and clinical relevance and are shown in Table. As in the 7th edition the IASLC Staging and Prognostic Factors Committee have attempted to resolve some issues in which data is limited by review of the literature and by consensus. These include how one should assess tumour size in the small tumours of mixed density increasing common when evaluation CT screen detected cancers. The committee's recommendation is that it should be the solid element on imaging, or the invasive component on pathological examination which should be measured to determine T size . In a series of articles the committee has given advice as to how one should classify the various scenarios in which multiple tumours are discovered in the lung(s) .
The IASLC has submitted all of these proposals to the Union for International Cancer Control (UICC) and the American Joint Committee on Cancer (AJCC), the 2 bodies that regulate the TNM classification for all tumour sites globally. The 8th edition is due to be published this Autumn. The IASLC will have extensive educational products available to attendees at the 17th World Conference on Lung Cancer, to be held in Vienna from the 4th to the 7th of December 2016.
Proposed T, N and M descriptors for the 8th edition
of TNM for Lung Cancer (changes to the 7th edition are highlighted in BOLD and
RED
T
|
Primary
Tumour
|
Tx
|
Primary
tumour cannot be assessed, or tumour proven by the presence of malignant
cells in sputum or bronchial washings but not visualized by imaging or
bronchoscopy
|
T0
|
No
evidence of primary tumour
|
Tis
|
Carcinoma
in situ
|
T1
|
Tumour
3 cm or less in greatest dimension, surrounded by lung or visceral pleura,
without bronchoscopic evidence of invasion more proximal than the lobar
bronchus (i.e. not in the main bronchus)
|
T1(mi)
|
Minimally invasive
adenocarcinoma
|
T1a
|
Tumour 1 cm or less in
greatest dimension
|
T1b
|
Tumour more than 1 cm
but not more than 2 cm in greatest dimension
|
T1c
|
Tumour more than 2 cm
but not more than 3 cm in greatest dimension
|
T2
|
Tumour
more than 3cm but
not more than 5 cm; or tumour with any of the following features : -
Involves main bronchus
regardless of distance from the carina, but without involvement of the
carina.
Invades
visceral pleura.
Associated with
atelectasis or obstructive pneumonitis that extends to the hilar region,
involving part or all of the lung
|
T2a
|
Tumour more than 3 cm
but not more than 4 cm in greatest dimension.
|
T2b
|
Tumour more than 4 cm
but not more than 5 cm in greatest dimension.
|
T3
|
Tumour more than 5 cm
but not more than 7 cm in greatest dimension,
or directly invades any of the
following structures: chest wall (including parietal pleura and superior
sulcus tumours), phrenic nerve, parietal pericardium; or associated with
separate tumour nodule(s) in the same lobe as the primary.
|
T4
|
Tumour more than 7 cm
in greatest dimension, or invades any of the following
structures: diaphragm,
mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve,
oesophagus, vertebral body, carina; or associated with separate tumour
nodule(s) in a different ipsilateral lobe to that of the primary.
|
N
|
Regional
Lymph Node Involvement
|
Nx
|
Regional
lymph nodes cannot be assessed
|
N0
|
No
regional lymph node metastasis.
|
N1
|
Metastasis
in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and
intrapulmonary nodes, including involvement by direct extension
|
N2
|
Metastasis
in ipsilateral mediastinal and/or subcarinal lymph node(s)
|
N3
|
Metastasis
in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral
scalene, or supraclavicular lymph node(s).
|
M
|
Distant
Metastasis
|
M0
|
No
distant metastasis
|
M1
|
Distant
metastasis present
|
M1a
|
Separate
tumour nodule(s) in a contralateral lobe; tumour with pleural or pericardial
nodule(s) or malignant pleural or pericardial effusion
|
M1b
|
Single extrathoracic metastasis
|
M1c
|
Multiple extrathoracic
metastases in one or several organs.
|
Proposed
Stage Groupings for 8th edition of TNM for Lung Cancer (changes to the 7th
edition are highlighted in yellow, bold and underlined).
