Lung Cancer
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Introduction
leading cause of cancer mortality
incidence: 60/100,000 in males; 40/100,000 in females
female lung cancer has increased 400%.
male lung cancer rates are decreasing.
The Case of...
a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.
Causes and Risk Factors
Smoking causes 85% of cases.
Remaining cancers are caused by
- second hand smoke
- radon
- radioactive mining
- asbestos
- aluminum
- coke ovens
- nickel
- vinyl something...
Pathophysiology
Non-small cell carcinoma
80%
squamous cell carcinoma
- central, bronchus
adenocarcinoma
- peripheral; now more common, potentially due to changes in cigarettes
- early brain metastases
- more common in females
bronchoalveolar
- more slowly growing
- more amenable to surgery
large cell anaplastic
Small cell carcinoma
- central
- neuroendocrine cells
- early lymph node spread; lymph nodes are often larger than primary tumour
- very aggressive
Peripheral nodules: no symptoms until it touches chest wall
central airway tumours:
airway obstruction, segmental lung collapse, infection, ventilation-perfusion mismatch, hemoptysis
metastatic disease: bone, brain, adrenals, liver
stage IIIa: mediastinal nodes; locally advanced tumour; small chance of cure
stage IV: metastatic
paraneoplastic syndromes
- perhaps 50-75
- not due to physical spread.
- hypertrophic pulmonary osteoarthopathy (HPO) - pain at the ends of distal long bones.
- syndrome of inappropriate ADH - low [sodium]
- ACTH, other hormonal abnormalities
- CNS
- hematological abnormalities - anemia, thrombocytopenia
Signs and Symptoms
- history
- physical exam
History
cough: change in pattern: increasing
hemoptysis
shortness of breath: though not normally an initial symptom
- smoking history
- old X rays
- TB, pneumonia, trauma, medical procedure history
pneumonia - persistent or recurrent, especially in same area
nonpulmonary thoracic symptoms
- chest wall infiltration and pain
- pancoast tumour: at apex of chest; pain in elbow or wrist due to brachial plexus involvement
- recurrent laryngeal nerve paralysis, especially on left
- SVC syndrome: obstruction
- phrenic nerve paralysis
Physical Exam
physical examination: feel for supraclavicular nodes
sympathetic innervation of face and eye leave cervical cord, around lung, synapses in sup cervical gangion, etc
ptosis, small pupil (myosis), anydrosis (decreased sweating)
cocaine (4%) drops will dilate a constircted pupil unless Horner's syndrome is present
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
blood work: alkaline phosphatase
selective mediastinoscopy
needle biopsy usually for patients with inoperable tumours
Diagnostic Imaging
chest X ray
CT scan
PET scans in the future
Differential Diagnosis
- hamartoma
- collagen - vascular disease
- infective - Wagner's granuloma, fungi (histoplasmosis): ask about travel history
Treatments
Decisions
high suspicion: surgery
uncertain: serial CT scans or surgery
low suspicion: serial CT scans
cell type, stage, patient
cure:
non small cell, stage 1: surgery: 65-80%
stage II surgery/chemo: 40-55%
small cell limited stage: xxxx 20%
lobectomy, pulmonectomy, chemotherapy, all have risk of mortality
palliation:
- radiotherapy
- chemotherapy
- endobronchial treatment: laser, stenting, brachytherapy
- general supportive care: pain control
- antiobiotics, psychosocial/spiritual
Consequences and Course
cure:
- males: 15%
- females: 18%
stage I: 60-80%
stage II: 40-55%
stage III: 10-15%
stage IV: 1-2%
Resources and References
Topic Development
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