L24 - Bronchogenic Carcinoma

Question 1

The problem with lung cancer is that most who get it die from it. Why?

Answer 1

Common - high incidence (2nd most common cancer in M and F)
Early stages asymptomatic
lousy treatments in advanced disease (50% present as advanced)
High mortality (#1 cause of mortality in M and F)

Question 2

Which is false regarding lung cancer being preventable? A. SMOKING 50% attributable risk with no clear safe threshold
B. Environmental, Occupational, Avocational Exposures such as biomass, coal burning, asbestos, heavy metals, radiation, Radon
C. Genetic – first degree relative increases risk 1.5 fold independent of smoking
D. Pulmonary fibrotic disease – prior injury, idiopathic, prior XRT, pneumoconiosis

Answer 2

A. SMOKING > 90% attributable risk with no clear safe threshold

Question 3

Small cell (SCLC) or Non-Small Cell (NSCLC)?

1. Neuroendocrine tumor spectrum
2. Large central mass with bulky nodes
3. Assumed metastatic at time of diagnosis – staging different than the other type of lung cancer
4. Limited vs. extensive; one hemi thorax vs. not; 30% vs. 70%
5. Chemoradiation is treatment of choice – little role for surgery
6. High prevalence of paraneoplastic syndromes

Answer 3

Small cell - 15-20% of all lung cancers

Question 4

SCLC can secrete the following hormones resulting in what paraneoplastic syndromes?

1. ACTH
2. Vasopressin
3. NMJ x-reactive ag (anti-VGCC)
4. Purkinje cell X-reactive ag (anti-yo Ab)

Answer 4

1. Cushings
2. Syndrome of Inappropriate Antidiuretic Hormone - hyponatremia
3. Lambert-Eaton Myesthenic syndrome (LEMS)
4. Cerebellar degeneration

Question 5

Small cell (SCLC) or Non-Small Cell (NSCLC) ?

1. Adenocarcinoma – 40%+ and increasing
2. Squamous Cell Carcinoma – 30% and decreasing - smoking related
3. Large Cell Carcinoma -

Answer 5

Non-small Cell - 80-85% of lung cancers

Adeno most common, but there are various histological types

Question 6

T/F Staging paradigm may not fully reflect biology

Answer 6

True due to the following assumptions
• Tumors start as small, single focus, and grow to threshold size before spreading.
• Initial spread via regional lymphatics is progressive to more central stations.
• Hematogenous spread occurs late and is proportional to tumor burden.

Question 7

TNM based system stages lung cancer. Define each letter

Answer 7

1. T factor = Tumor size
   (bigger = worse outcome)
2. N factor = nodal station involved
   (inc nodes, dec survival)
3. M factor = presence of extra-nodal metastases
   (metastasis related to dec survival)
   • Early stage disease defined by tumor size (T factor)
   • Nodal involvement classified by zones of regional drainage - N1 nodes resectable
   • Metastatic disease defines Stage 4 - malignant effusion (pleural or pericardial) M1a

Question 8

Why is staging important?

Answer 8

Stage implies therapy options and prognosis
Lower stages more resectable. No cure for stage IV (palliative care)
○ Stage I - surgery
○ Stage II - surgery + adjuvant chemo
○ Stage IIIA - neoadjuvant chemoXRT +/- surgery
○ Stage IIIB/IV - palliative chemotherapy, palliative XRT, Hospice care
○ Evolving roles of targeted therapy altering landscape for Dx and Rx

Question 9

1. T/F lung cancer screening is never done by accident
2. Effective screening involves what 2 things?
3. T/F screening studies using CXR showed survival benefit and more cancers found

Answer 9

1. False. May get CT for different problem and find lung cancer.
2. Ability to detect disease prior to clinical symptoms and
   Early detection should lead to improved outcome
3. False. NO survival benefit

Question 10

National Lung Screening Trial compared 3 annual CTs vs 3 annual CXR.

1. Which group had 40% positive findings vs 15% and what did this indicate?
2. T/F >95% of the positive findings in the CT group only proved to be benign
3. 3 annual low dose CT screens in high-risk smokers reduced lung cancer death by 20%

Answer 10

1. CT had 40% positive findings indicating CT is better at detecting lung nodules than CXR.
2. F - in BOTH groups
3. True

Low Dose Chest CT screening can reduce Lung Cancer mortality in high risk subjects
• Ages 55 to 75, Smokers with > 30 pack years, exsmokers quit

Question 11

1. T/F radiographic observation is a type of screening
2. Why is it done?
3. What is done?

Answer 11

1. False - it is surveillance
2. After CT since many patients are found with nodules (40%) but so few are cancers (95% benign)
3. Interval imaging 3-6 mo; stability after 2 years is reassuring (not cancer)
   Look for growth, shape, density, location, size

Question 12

Which is false regarding metabolic screening (FDG PET CT)?
A. Sensitive – though some well differentiated adeno are negative
B. Not specific – granulomas, infection also FDG-avid
C. Good for small nodules

Answer 12

C. Not good for small nodules - Resolution drops off at diameters of

Question 13

Lung Cancer may be more like breast cancer: disease may be systemic even at “early stage.”
This may be due to:
• Circulating tumor stem cells
• Multifocal field effect
T/F this means our staging paradigm is good

Answer 13

False = Tumor biology may trump staging.

Question 14

density that may obscure the diaphragm and RH border on CXR of a patient with lung cancer?

Answer 14

silhouette sign

Question 15

curvilinear margin where density contacts the chest on CXR - sign of pleural effusion

Answer 15

Meniscus

If the fluid is drained and a tumor is found in the lung, this would be stage IV due to the malignant pleural effusion

Question 16

Which is false regarding stage IV lung cancer?

A. Terminal disease with median survival

Answer 16

F. No role for surgery: occasional solitary brain met resection, spinal cord compression, stabilize pathologic fracture, etc.

Question 17

Lung cancer targeted therapies:

1. T/F: Effective tumor-specific targets only now being recognized
2. T/F: Cellular genetic expression patterns likely less important than histology
3. T/F: 65 to 80% of NSCLC have abnormal regulation so Growth Factor Receptors and downstream paths are targeted for therapy
4. Growth factor therapy involves exposing tumors to native tumor surveillance

Answer 17

1. True
2. False - more important
3. True
4. False - Immunotherapy

Question 18

Pleural Space is complex - negative pressure and “dry” normally - “breathing sucks”. Which is true?
A. Pleural Effusion is air in pleural space
B. Fluid accumulates: due to changes in hydrostatic/oncotic forces OR altered capillary or mesothelial permeability
C. Exudate = total protein fluid/serum 0.5 OR LDH fluid/serum > 0.67
E. If fluid is a EXUDATE, problem not in the pleural space!

Answer 18

B
A. Pleural Effusion is FLUID in pleural space
B. Fluid accumulates: a) changes in hydrostatic/oncotic forces, b) altered capillary or mesothelial permeability
C. Transudate = total protein fluid/serum 0.5 OR LDH fluid/serum > 0.67
E. If fluid is a TRANSUDATE, problem not in the pleural space!

Question 19

What is the ddx of Small Cell Carcinoma with SIADH and Cerebellar Ataxia (3)?

Answer 19

• 1) CNS effects of hyponatremia
○ Usually at much lower sodium or rapidly acquired hyponatremia.
○ More commonly causes altered mental status or seizures.
• 2) Paraneoplastic Cerebellar Ataxia
○ Autoimmune, anti-YO antibodies destroy cerebellar Purkinje Cells.
○ May not remit with treatment of cancer.
• 3) Cerebellar Metastases

Question 20

1. T/F: Extensive Small Carcinoma - chemotherapy and stereotactic radiation to brain mets.
2. T/F: Limited Small Carcinoma - chemotherapy and prophylactic radiation to brain.

Answer 20

1. True

2. True