Thoracic Surgery
Lec 7
Lung Cancer:-
Is one of the Major Killer Cancers World
Wide.
Etiology :-
1. Smoking accounts for 75% of all lung cancers
especially Squamus and Small cell type.
2. Exposure to industrial compounds e.g. Asbestos, Zn , Cr
3.previous Hx of T.B with scar formation.
4. Cooking Oil Vapors and Indoor coal and wood burning.
Histopathology:-
It can be divided to 2 stages
A- Preinvasive lesions :they are Subclassified to 3 categories
1. Squamous dysplsia and Carcinoma In Situ (CIS ): which will
progress to squamous cell carcinoma
2. Atypical adenomatus Hyperplasia: which will progress to
adenocarcinoma
3. Diffuse idiopathic Pulmonary Neuroendocrine (NEC )
Hyperplasia: which will progress to NEC tumors
B- Invasive or Malignant lesions : also subclassified to 2 Major
kinds
Subclassified to 4
–
Small cell Lung Cancer ( NSCLC )
-
1. Non
Kinds Which are Similar in Their Clinical behavior and Rx
Options.
a.Squamous cell Carcinoma / 30 – 40% of Ca Lung , M > F ,
associate with Smoking , involve Major Bronchi i.e located
centrally , sometimes found peripherally in previous T.B Scar or in
the wall of Bronchiactatic cavity , may present as Cavitory Lesion
with Air –Fluid Level
b.Adeno Carcinoma / 25 - 40% of Ca Lung , F > M, mostly found
Peripherally and mostly Dx incidentally on CXR
c. Broncho-alveolar Carcinoma / Is asubgroup of adenocarcinoma
d. Large Cell Carcinoma / 10 -20 % of Lung Ca May be Central or
Peripheral
2. NEC Tumors. /are the major leading cause of para neoplastic
syndrome they are classified to 3 kind
Grade 1 NEC (Classical or Typical Carcinoid ) /Low Grade ,
involve central airways , found in young Pts
Grade 2 NEC ( Atypical Carcinoid ) / have more aggressive
clinical behavior , associate with smoking , occur peripherally , 30
-50% have L.N metastasis at time of Dx
Grade 3 NEC ( Small Cell Type ) /is most malignant, represent
25% of all lung cancers , located centrally
CLINICAL FEATURES:-
CA.lung presents with diverse
presentations according to:
The anatomical site of origin of tumour in the lung
1.
2. Biological features of tumour
3. presence of metastatic disease
4. Tumour Histolog.
1
.Tumor Location and Histology
Squamous c.ca.- arise in main, lober , first segmental bronchi
which known as Central Airways and produce signs and
symtoms of Airways irritation or obstruction e.g cough,
haemoptysis, wheeze, S.O.B, Pneumonia.
Peripheral Tumours e.g adeno Ca. remain_Asymtomatic and
they are either diagnosed Incidentally on CXR. or symtoms may
occur due to invasion of the Primary tumor directly into
contagious structures e.g
1. chest wall invasion leads to Local chest wall pain
2.Intercostal Nerve involvement leads to Radicular chest pain
3.Irritation or invasion of Parietal pleura Leads to Pleuritic chest
pain
4.Invasion to Satallate ganglion , Brachial Plexus can produce
Pancoast Syndrome
5.Recurrent Laryngeal N involvement produce Hoarseness of
Voice 6.SVC involvement leads to swelling of head and
neck
2
.Tumor Biology
The Majority of symptoms are due to Small cell ca. which
produce paraneoplstic features which may present even before
the appearance of symptoms produced by primary tumor leading
to early Dx , more common symptoms are –
1.Skeletal e.g Hypertrophic pulmonary osteoarthropathy /
clubbing :- Pt. present with tender swelling of Ankle, Feet,
Forearm, Hand X-ray shows Periosteal elevation of the affected
area.
2. Endocrine e.g a. Hypercalcemia dueto PTH-Like secretion
leads to depressed conciousness , vomiting , Dehydration
b.Cushing Syndrome dueto increaseACTH Like Secretion
leads to hypokalemia , autonomus increase in ACTH Secretion
which cannot be suppressed By External Dexamethasone ,
increase cortisol level with loss of diurenal variation
c. Carcinoid Syndrome.
3.Neurogenic symtoms e.g Peripheral and Central Neuropathy /
they are Immune mediated i.e Ag normally expressed by N.S are
expressed aberrantly by Ca Cells generating Ab which may
interfere with N.S function or neurologic destruction.
4.Heamatologic / Anemia, increase or decrease in platelets ,
DIC .
3.
Metastatic Symtoms
1. 10% have CNS metastasis at time of Dx leading to head ache ,
fits , hemiplegia , Speech disturbance .
2. Spinal Cord Compression / due to local extension of tumor
near to vertebral body OR from vertebral body metastasis
3. Liver metastasis found incidentally on CT Scan
4. SupraClavicular and Cervical L.N Metastasis.
Diagnostic Evaluation :-
Assessment of Pt. with Lung Ca
consist of 2 Stages:-
1.assessment of Primary Tu.
1. careful History taking regarding any pulmonary ,
nonpulmonary , thoracic , paraneoplastic symtoms
2. CT Scan with I.V Contrast to assess primary Tu. And its
relation to contagious structures
3. MRI used when Pt. has allergy to contrast material OR with
suspected Mediastinal , Vertebral , Vascular invasion since
MRI has excellent imaging of vascular structures
4.Tissue Dx May be obtained by:A-Bronchoscopy: Useful for
Central Tumors to get Endobronchial Dx, also to visualize entire
trachea-bronchial tree, Dxic Speciman May be Obtained by
direct Forceps Biopsy of lesions seen followed by Bronchial
Wash and Brush for cytological analysis, this will help to
improve the Yield of Biopsy by picking up additional cells after
disruption of lesion by biopsy forceps
B– TransthoracicFNAC is suitable for peripheral lesions not
accessible by Bronchoscopy under fluoroscopy or CT guide.
C– Thoracoscopy is used to assess relation of primary tumor to
other intrathoracic structures , also help to take biopsy from
lesions not accessible by previous methods and Surgeon can
proceed to Lobectomy after Frozen Section Dx.
D- Open Dxic Thoracotomy may be done when 1. there is deep
seated lesion that yielded indeterminate biopsy results Or
Lesions which could not be biopsied due to Technical reasons
2. inability to determine invasion of Mediastinal structures by
any method other than palpation, in this situation all preparations
must be carried out to proceed for complete Tumor resection if it
is proved to be malignant in the same operation, therefore; this
option is reserved only for resectable tumors.
2. Assessment of Distant Metastasis:-
40% of Pt.s with newly Dxed Ca Lung have distant metastasis
which may be assessed by
1. asking about any Bone pain and Neurological symtoms and
look for Cervical and Supraclavicular LN.s
2. CT scan can assess Mediastinal LN Metastasis
3. PET ( Pesitron Emission Tomography ) allows whole body
scan after single injection of Fluorine Labelled D- glucose
(FDG) which allows simultaneous evaluation of primary tumor,
Mediastinal LNs and Distant Metastasis
4. Cervical , Mediastinal , paratracheal LN. biopsy may be
required to settle Dx and possibility of LN involvement
5. The presence of pleural effusion with Ca Lung is mostly
Malignant but this must be proved cytologically
6. Thoracoscopy may be indicated to exclude pleural metastasis.
Preparation of Pt. for surgery:-
Regarding Hx: 1. if Pt. can walk on flat surface indefinitely
with no need to take rest usually can tolerate Lobectomy
2. if Pt. can walk up 2 flights of stairs with out rest usually can
tolerate Pneumonectomy
3. Smoking increase post operative pulmonary complications
e.g pneumonia , atelactasis , Respiratory failure especially when
patient smoks > 60 pack / Yr. , Pt. must stop smoking totally at
least 2 Wks before surgery + Chest physiotherapy + Antibiotics
+ Bronchodilators and Expecturants must be given pre-
operatively.
4. Pulmonary Function Tests ( PFT) must be done , we concern
on value of FEV1 , if FEV1 > 2Liters Pt. can tolerate
Pneumonectoy , When FEV1 > 1.5 Liters Pt. can tolerate
Lobectomy , FEV1 < 50% of predicted value increase risk of
post-operative complications
Post operative Remained Predictive FEV1 Value can be
calculated by Equation (20 - No. of resected segments / 20 ) ×
100 = % Remained from original lung capacity.
Lung Ca. Staging systems / The international Tumor – Node –
Metastasis ( TNM ) on Ca. staging system for Ca Lung.
Primary Tumor (T)
1. Tx Tumor proven by presence of malignant cells and
bronchial secretions but not visualized by radiography or
bronchoscopy.
2. T0 No evidence of primary tumor.
3. TIS Carcinoma insitu.
4. T1 A tumor that is 3 cm or less in greatest dimension,
surrounded by lung or visceral pleura and without evidence of
invasion proximal to a lober bronchus at bronchoscopy.
5. T2 A tumor of more than 3cm in greatest dimension or tu. Of
any size that either invades the visceral pleura or has associated
Atelactasis or obstructive pneumonitis which extends to
hilar region , but doesnot involve the entire lung . at
bronchoscopy the
Proximal extent of demonstrable Tu.must be with in a
lober bronchus or at least 2 cm distal to carina.
6. T3 A tumor of any size with direct extension into the chest
wall (including superior sulcus tumor), diaphragm, mediastinal
pleura
Or pericardium, without involving the heart, great vessels,
esophagus, treachea, vertebral body, Or Tu. In the main
bronchus
Within 2 cm from the carina but without involving the
carina.
7. T4 A tumor of any size with invasion of the mediastinum, the
heart, great vessels, trachea, esophagus, vertebral body, carina
Or
The presence of malignant pleural effusion.
Nodal involvement (N)
1. N0 No demonstrable metastasis or regional lymph node.
2. N1 Metastasis to L.N in the peribronchial and/or ipsilateral
hilar region including direct extension.
3. N2 Metastasis to ipsilateral mediastinal or sub carinal L.Ns.
4. N3 Metastasis to the contralateral mediastinal L.Ns. ,
contralateral hilar L.Ns , supraclavicular or scalenus L.Ns.
Distant metastasis (m)
1. M0 No known distant metastasis.
2. M1 Presence of distant metastasis.
Summary of staging :-
Stage TNM
1A T1N0M0
1B T2N0 M0
2A T1N1M0
2B T2N1M0 or
T3N0M0
3A T3N1M0 or T1-
3N2M0
3B T4 any N M0 or any
T N3 M0
4 any T any N M1
Treatment :-
1. Early stage / stageΙ and П diseases Rxed
by Surgical
resection according to site of tumor mostly by Lobectomy
Pneumonectomy may be required for large central tumor
involve distal main stem bronchus with inability to resect hilar
L.Ns and is usually followed by post opt. chemotherapy (CRx)
2.stage Шa
tumors like Pancoast tumor which arise at the apex
of chest , shoulder pain , Horner syndrome which involve
parietal pleura and deep layers of chest wall Or Superior Sulcus
Tumor Rxed by Pre-opt. CRx followed by Surgery
(Thoracotomy +Resection of involved chest wall and vascular
structures and lower Trunks of Brachial Plexus +Lobectomy.
Defect in the chest wall require reconstruction by Poly Tetra
Floro Ethylene (PTFE) or by Gortex material
T3 Tumors Rxed by Enbloc Resectionwith adjacent structures
i.e chest wall , diaphragm , pericardium which must be replaced
by Gore-Tex memberane to prevent Cardiac Herniation and
venous obstruction followed by postopt.CRx.
Pt. with limited pulmonary reserve we do limited surgical
resection( segmental Or wedge resection) followed by Radio
therapy (RRx) , this suitable for peripheral Tumors but associate
with increased risk of local reccurence while for central tumors
we use definitive RRx with advanced method which include
1.Tomotherapy
2.Robotic Radiosurgery (Cyber Knife ) Rx. Which deliver high
dose radiation in several sesscions directly to tumor cells but not
to normal lung tissue this will decrease toxicity
3.stage Шb tu.
treated by CRx + RRx, for poor risk Pt.s this
may be given either as full dose CRx followed by RRx OR as
concurrent CRx and RRx at same time this will help to sensitize
tumor cells to radiation effect leading to improved control of
Primary tumor and involve LNs and lack of delay to take RRx.
4.Stage ΙV diseases Rxed by CRx.
Pre-opt.(induction)CRx For NSCLC :-
1.Advantages
a. The Tu. Blood supply is still intact this allows better CRx
delivery and avoid Tu. Cell hypoxia( in any residual microscopic
tumor remaining postopt.)which would increase Radioresistance
b. The Primary Tu. May be downstaged with enhanced
respectability
c. Pt are more able to tolerate Pre-opt. CRx than after surgery.
d. Systemic micrometastasis are Rxed
e. Non-responder Pt.s are identified and spared pulmonary
resection.
2.Disadvantage :- While the Pt. is receiving CRx , curative
resection is delayed; if the Pt. doesnot respond, this delay could
result in Tu. Spread.
Small Cell Lung Cancer :-
generally not Rxed Surgically since they are aggressive and
have early wide spread metastasis, they are classified to
1. Local or Limited disease:- present with bulky Primary Tu.
With mediastinal LAP which may lead to SVC obstruction
2. Disseminated disease:- present with metastatic disease
through out the body
Rx :- is by combination of CRx and RRx regardless of the stage
of presentation.
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