Journal Thoracic Oncology

Abstracts Journal of Thoracic Oncology • Volume 12 Issue S1 January 2017
INTERACTIVE SESSIONS
SESSION IA01: MULTIDISCIPLINARY DIAGNOSIS OF LUNG
CANCER IN THE ERA OF MOLECULAR MEDICINE
MONDAY, DECEMBER 5, 2016 - 11:00-12:30
IA01.04 DOES CYTOLOGICAL MATERIAL FIT ALL - LESSONS FROM
EBUS/BRONCHOSCOPY
Wlodzimierz Olszewski
Pathology, Institute of Oncology, Warsaw/Poland
In the diagnosis of lung cancer the primary diagnostic approach is microscopic
evaluation of tissue biopsy. However, in many cases the only material for
microscopic evaluation is cytological one. There are numerous types of
cytological material in evaluation of lung tumors including sputum, bronchial
brush, bronchial washing, transthoracic and transbronchial fine needle
aspirates. Historically sputum was the most common diagnostic material
but at present the most common types of cytological specimen are bronchial
brush, and transthoracic or transbronchial FNAB. Nowadays worked out and
recognized cytological criteria allows not only to diagnose carcinoma but
in majority of cases to specify the histologic type of a tumor. This approach
to microscopic diagnosis of lung carcinoma was incorporated to the latest
WHO classification of lung tumors (ref). The key reason that cytodiagnosic
criteria and terminology were included into WHO classification was that
in about 30% cases of lung tumors the cytological specimen is the only
material for microscopic evaluation. Similarly to evaluation of small tissue
biopsies in cytopathology, in doubtful cases, immunocytochemistry may be
implemented to determine histologic type of tumor. Most useful in evaluation
of cytological specimen are IHC antibodies with nuclear presentation. (e.g.
p40 for squamous cell carcinoma and TTF1 for adenocarcinoma). Cytological
material may be utilized in evaluation and in differential diagnosis between
primary and metastatic lung tumor. The panel of the antibodies (e.g. CDX2,
PSA, Melan A ) may be used to indicate location of primary tumors mainly
adenocarcinomas. Since cytological smears are of limited diagnostic
value for immunocytochemistry, the so-called cell blocs technique is
recommended. This technique allows to use larger panel of antibodies for
immunohistochemical evaluation. Cytology become very useful for clinical
staging of lung carcinoma routinely utilizing EBUS and EUS technique for
obtaining material from parahilar and mediastinal lymph nodes. Cytological
criteria are similar to that used for specimens obtained by transthoracic
FNAB. In our center practice cooperation with adequately trained thorax
surgeons provides adequate material for microscopic evaluation from EBUS
and EUS obtained specimens in 94% cases. Currently one of the important
task for pathologist in evaluating material from lung carcinoma is adequate
selection of the material for molecular test. In case of lung carcinoma or to be
specific lung adenocarcinoma â material is selected for evaluation of EGFR
and K-RAS mutation. In our experience cytological material particularly
fine needle aspirates - fulfill such demands. Percentages of tumors cells in
the sample is often even higher than in tissue sections especially in fine
needles of peripherally location lesions. Cytological material may be useful
in evaluation of EGFR and K-RAS mutation as well as in determination of
presence of translocations of ALK and ROS1 using FISH technique. Evaluation
of ALK and ROS1 translocation remained in the hands of cytopathologists
since the crucial point is the location of translocation in nuclei of tumors
cells. Latest challenge for pathologists evaluating lung carcinoma specimen
is to determine predictive criteria for immunotherapy in those tumors. At
the moment it seems that cytological material may be not satisfactory for
adequate evaluation of immunocytochemical expression of PD-L1 and PD-1.
In summary cytological material from lung carcinoma is useful in establishing
the firm microscopic diagnosis of malignancy, to determine histologic type
and to be used for molecular tests. It also allows to differentiated between
primary and metastatic lung malignancies as well as determined primary
location of metastatic lung carcinoma. Cytological specimens obtained
by EBUS and EBUS techniques are very useful in clinical staging of lung
carcinoma. Reference Travis WD, Brambilla E, Burke AP, Marx A, Nicholson AG
eds. WHO Classification of Tumours of the Lung, Pleura, Thymus and Heart.
4 th ed. Lyon, France: IARC Press; 2015
Keywords: cytology, lung carcinoma, molecular testing
SESSION IA05: THE PRACTICAL USE OF THE TNM CLASSIFI-
CATIONS FOR THORACIC CANCERS
TUESDAY, DECEMBER 6, 2016 - 11:00-12:30
IA05.01 LUNG CANCER CASES
Gustavo Lyons
Thoracic Surgery, Buenos Aires British Hospital, Ciudad de Buenos Aires/Argentina
The definition of staging in Lung Cancer is the determination of the anatomic
extent of three tumor components: the primary tumor (T), the lymph nodes
(N), and the metastases (M). Their accurate evaluation allows grouping
patients in stages that is one, and perhaps the single most important, of
several prognostic factors that guide the appropriate treatment option(s) to
offer the patient. The clinical classification cTNM (Pre-treatment clinical
classification), is based on evidence acquired before treatment The
pathological classification pTNM (Post-surgical histopathological
classification), is based on the evidence acquired before treatment,
supplemented or modified by the additional evidence acquired from surgery
and from pathological examination. A minimum number of tests is not
required to define the extent of the disease, but it’s very clear that as more
exhaustive the explorations more accurate and precise the staging will be.
This may be strongly affected by the availability of physical and human
resources, multidisciplinary work and adherence to clinical practice
guidelines. After the changes proposed by the new IASLC-ATS-ERS lung
adenocarcinoma classification and the IASLC proposals for revision of the T, N
and M descriptors and stage groupings in the forthcoming (Eighth) edition of
the TNM Classification for Lung Cancer, we must incorporate this new
information into our clinical practice. (1, 2) The changes that The IASLC
Staging Committee recommends for the T, N and M components and the
resulting new stage grouping and their survival are summarized in table 1 and
figure 1. The main changes in T components are the relevance of the size of the
tumor for each cm, grouping of the involvement of the main bronchus or
partial and total atelectasis or pneumonitis as a T2 descriptor and the
reclassification of diaphragm invasion as T4. (3) N component remains
without changes. (4) In M component a new M1b category includes patients
with a single metastatic lesion in a single organ site and a new M1c category
was introduce for patients with multiple lesions in a single organ or multiple
lesions in multiple organs. (5) Some new stage groupings are proposed. The
new size cut points of T1-N0-M0 tumors has been assigned to stage IA1, IA2,
and IA3. The new stage IIIC (T3 and T4-N3-M0) reflects their worse outcome.
Finally, stage IV disease has been divided into IVA (M1a, M1b) and IVB (M1c).
The new IVA stage grouping should be used in trials analyzing patients with
oligo-metastasis or pleural or pericardial disease. (2) For the newly described
types of adenocarcinoma of the lung, The IASLC recommends incorporating
the coding of AIS as Tis (AIS) and of MIA as T1mi into the traditional TNM
classification. For part-solid tumors, the size of the invasive component
should be used to assign a T category, but the whole tumor size should also be
recorded. However, the measurements will be influenced by a number of
observer-dependent and technical factors. It is important to perform the
measurements for clinical staging on contiguous thin CT sections
reconstructed with a high-resolution algorithm with multiplanar
reconstruction. (6) For pathologic staging, attention should be given to the
assessment of invasive and lepidic components. It can be helpful to correlate
microscopic findings with measurements made on gross examination,
particularly in inflated specimens or with CT findings. Patients who present
with more than one pulmonary site of lung cancer may represent different
patterns of disease as synchronous primary lung cancers, those with a
separate solid tumor nodule(s) (intrapulmonary metastases), multifocal lung
cancer presenting as multiple nodules with ground glass/lepidic features, and
diffuse pneumonic-type adenocarcinoma. It is proposed that the T category of
patients presenting ground glass/lepidic (GG/L) tumors be classified using the
T category of the highest T lesion and in parentheses either the number of
GG/L tumors or simply m for multiple (#/m). A single N and M category is
assigned for all GG/L tumors combined. (7) Both clinical information (the
presence of additional lesions identified by imaging) and the pathologic
information (from resected lesions) should be used to determine the TNM
classification. Lesions smaller than 5 mm or AAH are not counted. The
pneumonic type of adenocarcinoma should be classified according to the size
of the area of lung involved, or as T4 or M1a in the case of involvement of more
than one lobe (i.e., either ipsilateral or contralateral). A single N and M
category is assigned. In patients with separate tumor nodules
(intrapulmonary metastases), it is proposed that the seventh edition
classification of same-lobe nodules as T3, same side (different lobe) nodules
as T4, and other-side nodules as M1a be carried forward. (8) It is easier to
establish that two pulmonary foci of cancer are separate primary tumors than
that they are metastatic from one another. Few features are sufficiently
reliable by themselves, such as different histologic type and differences by a
comprehensive histologic assessment of resected specimens or by matching
breakpoints by DNA sequencing. Most criteria can be suggestive, but are
associated with potential misclassification. These include biomarker
patterns, imaging characteristics, and the presence or absence of nodal
involvement. The fact that generally only biopsy specimens are available at
the time of clinical decision making further adds to the uncertainty and
difficulty of the assessment. A constellation of factors is better than any
single factor; it is best to make a determination of separate primary versus
metastatic lesions through a collective judgment of a multidisciplinary tumor
board after taking into account all of the available information. (9)
Synchronous primary cancers are classified with a T, N, and M category for
each tumor; separate tumor nodules result in a T3, T4, or M1a category
depending on the separate nodule’s location relative to the primary tumor.
S98 Journal of Thoracic Oncology • Volume 12 Issue S1 January 2017