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Diagnosis Amp Staging Of Lung Cancer

Lung Cancer Staging

1. Staging Process

A. Histology
- small cell vs.. non-small cell
B. Sputum
1) 20- 70% sensitive, but tumor location plays a significant role
2) histology is predictive of yield, i.e. squamous is more often positive followed by adenocarcinoma, and finally small cell
3) when cytology is positive it predicts the cell type with 85% accuracy
C. Bronchoscopy
1) direct visualization or positive biopsy in 25-50% of patients with lung cancer
D. Fine needle aspiration
1) percutaneous or transbronchial
2) 84-95% accurate with peripheral lesions
F. Thoracotomy

2. Staging Classification

A. International Staging System for Non- Small Cell Carcinoma
1) T Primary Tumor
a) Tx - positive cytology only
b) To - no evidence of tumor
c) Tis - carcinoma in situ
d) T1 - size < 3 cm
(1) no pleural invasion
(2) distal to lobar bronchus
e) T2 - size > 3 cm
(1) any size invading the visceral pleura
(2) associated atelectesis or pneumonitis to the hilum
(3) >2 cm from the carina
f) T3 - any size with chest wall, diaphragm, mediastinal pleura, or pericardium, (i.e. locally metastatic to resectable ipsilateral hemithorax)
(1) < 2 cm from the carina
g) T4 - invasion of the mediastinum, heart, great vessels, vertebral body, esophagus, or carina
2) N Nodal Involvement
a) N0 - no nodes
b) N1 - peribronchial or ipsilateral hilar
c) N2 - ipsilateral mediastinum or subcarinal
d) N3 - any contralateral node
e) ipsilateral supraclavicular or scalene nodes
3) M Distant Metastasis
a) Mo - no mets
b) M1 - distant mets
B. Small Cell Carcinoma
1) localized - disease of the ipsilateral hemithorax including the supraclavicular nodes and a positive pleural effusion
2) extensive - disease beyond the ipsilateral hemithorax

3. Clinical Presentation

A. Symptoms
1) bronchopulmonary
2) extrapulmonary intrathoracic
3) extrapulmonary metastatic
4) extra pulmonary nonmetastatic ( i.e. paraneoplastic)
a) carcinomatous neuromyopathy is the most common paraneoplastic syndrome with 15% of patients with lung cancer affected
(1) mysthenia gravis - like syndrome
(2) polymyositis
b) Cushing's - small cell
c) SIADH - small cell
d) hypercalcemia - squamous
e) gynecomastia - small cell
f) Gonadotropin - undifferentiated large cell
B. Signs
1) clubbing is the most common
2) Hypertrophic pulmonary osteoarthropathy
a) periosteal elevation at the ends of long bones
b) 2-12% of all lung cancer patients
c) not seen in small cell
C. Tumor Makers/ Oncogenes
1) generally not help for diagnosing lung cancer

5. Diagnostic Evaluation

1) CXR findings proceed symptoms by 7 months
2) sensitive to 1 cm
3) nodule most common finding
a) squamous
(1) obstructive pneumonitis
(2) collapse
(3) consolidation
(4) 1/3 are peripheral
(5) 20% have cavitation
b) adenocarcinoma
(1) peripheral
(2) < 3 cm
(3) bronchoalveolar have parenchymal changes
c) Large cell (undifferentiated)
(1) 60% are peripheral
(2) 2/3 > 4 cm
d) small cell
(1) 80% hilar abnormalities
(2) 2/5 associated parenchymal changes
B. Other Studies
1) CT
a) best for evaluating the mediastinal adenopathy and adrenals
b) chest wall invasion is poorly seen
c) paraesophageal and inferior pulmonary nodes not well seen
d) nodes < 1 cm have a 7% chance of being malignant
e) nodes > 1 cm have a 55-65% chance of being malignant
2) MRI
a) better than CT at evaluating vascular invasion and chest wall invasion esp. superior sulcus
3) Ultrasound
a) ? TEE for evaluating mediastinal adenopathy
4) PET
a) may help determine malignant vs. benign peripheral nodules
5) Bone Scan
a) helpful in stage IIIA and IIIB disease

6. Lymph Nodes

A. Biopsy
1) biopsy palpable neck nodes
2) mediastinoscopy is controversial
1) 85-95% sensitive
1) good for evaluating aortopulmonary window

7. Completion of Staging

A. -25% of patients worked up will be resectible
B. -25% will have stage IIIB
C. -50% will have stage IV

8. Posthoracotomy provides the definitive stage and should be the basis of treatment plans

9. Functional Status

A. Associated with prohibitive operative risk
1) FEV1 < 40%
2) Predicted postop FEV1 < 30%
3) MVV < 45-50%
4) DLCO < 40%
5) PCO2 > 45 mmHg
6) peak VO2 < 10 ml/kg