B2.062 Lung Cancer

Question 1

when is the peak incidence for lung cancer?

Answer 1

40-70 years

Question 2

what are the 3 primary types of bronchogenic carcinoma?

Answer 2

small cell carcinoma (10-15%)
adenocarcinoma (40%)
squamous cell carcinoma (25-30%)

Question 3

what constitutes a bronchogenic carcinoma?

Answer 3

cancers of epithelial elements of the lung itself

Question 4

what cells form lung adenocarcinomas?

Answer 4

gland forming epithelium

columnar epithelium in respiratory tract/lungs

Question 5

what cells form lung squamous cell carcinomas?

Answer 5

squamous epithelium
normally no squamous cells in the respiratory tract
arise from pathologic metaplasia bc squamous are more resilient

Question 6

what factors other than smoking could induce patches of squamous cell metaplasia?

Answer 6

harsh environmental exposures

Question 7

what % of lung cancers occur in smokers?

Answer 7

80%

Question 8

what % of heavy smokers get lung cancers?

Answer 8

11%

Question 9

how do cytochrome p-450 polymorphisms relate to lung cancer?

Answer 9

cytochrome p-450 is responsible for the metabolism of procarcinogens into carcinogens

Question 10

how do DNA repair gene mutations affect lung cancer?

Answer 10

toxic damage more likely to cause cancer in cells with mutated repair mechanisms

Question 11

what is the latent period of asbestos?

Answer 11

> > 10 years

very long

Question 12

what is the most common malignancy associated with asbestos exposure?

Answer 12

lung cancer

FAR more common than mesothelioma, mesothelioma just easier to prove a direct correlation (lawsuits)

Question 13

how is asbestos exposure affected by smoking?

Answer 13

incidence of lung cancer due to asbestos exposure is increased 10 fold when coupled with smoking

Question 14

what oncogenes are linked to lung cancer?

Answer 14

receptor tyrosine kinases (EGFR, ALK, ROS, MET, RET)
KRAS (G protein)
MYC (transcription factor)

Question 15

what is the goal of lung cancer screening?

Answer 15

detect small cancers

too hard to detect abnormalities before they occur

Question 16

what methods can be used to screen high risk individuals?

Answer 16

CT

Question 17

what are some clinical features of lung cancer?

Answer 17

cough
weight loss
chest pain
dyspnea

Question 18

what are 3 general effects of local invasion and their reason for arising?

Answer 18

hemoptysis- destruction of blood vessels in lungs
pneumonia- tumor can obstruct and cause poor perfusion in a portion of the lung
pleural effusion- inflammatory mediators or tumor can move into pleural space

Question 19

what is horner syndrome?

Answer 19

invasion of cervical sympathetic nerve plexus by apical tumors
pain in ulnar nerve, ptosis, miosis (pupillary constriction), anhidrosis (inability to sweat) on same side as lesion

Question 20

what is superior vena cava syndrome?

Answer 20

pressure on SVC causing obstruction

facial edema, distention of neck veins, compressive symptoms

Question 21

what are common symptoms of lung cancer metastasis?

Answer 21

bone pain
headache
seizures
other CNS findings

Question 22

what are common sites of lung cancer metastasis?

Answer 22

lymph nodes, liver, adrenal gland, bone, brain

Question 23

what is the etiology behind paraneoplastic syndrome?

Answer 23

inappropriate secretion of hormone or hormone like substance by tumor cells
autoantibodies

Question 24

what are some examples of paraneoplastic syndromes associated w lung cancers?

Answer 24

cushing syndrome- ACTH (small cell carcinoma)
syndrome of inappropriate ADH secretion- ADH (small cell carcinoma)
hypercalcemia- PTH, PTH-RP (squamous cell carcinoma)
myasthenia gravis/ Lambert-Eaton syndrome- autoantibodies
clubbing- hypertrophic pulmonary osteoarthropathy

Question 25

characterize adenocarcinoma lung cancers

Answer 25

most common subtype, especially in women
peripheral location (smaller airways)
acinar, papillary, lepidic types
most common lung cancer in never smokers

Question 26

what are common characteristic in lung cancer of never smokers?

Answer 26

most adenocarcinomas
more common in women
most have EGFR or other receptor tyrosine kinase mutations
NOT typically KRAS mutations
more responsive to targeted molecular therapy

Question 27

why should you test for KRAS mutations in adenocarcinomas?

Answer 27

if you want to treat with a tyrosine kinase inhibitor, this WILL NOT work if there is also a KRAS mutation downstream in the signaling pathway

Question 28

why is a RAS mutation hard to target in therapy?

Answer 28

common G-protein for many life functions

Question 29

characterize squamous cell carcinoma lung cancer

Answer 29

highly associated with smoking
more common in males
usually central in location
usually due to deletion of tumor suppressor genes (more resistant to chemo and radiation)

Question 30

what is a histologic marker of a squamous cell?

Answer 30

keratin production

Question 31

characterize small cell carcinoma lung cancer

Answer 31

highly associated with smoking
most aggressive course 
frequently metastatic at presentation
arise from neuroendocrine cells
very poor survival

Question 32

what is a histologic marker of small cell carcinoma?

Answer 32

high nucleus to cytoplasm ratio

Question 33

characterize mesothelioma

Answer 33

arise from mesothelium (pleura, other serosal membranes)
strongly associated with asbestos
pleural effusion common
poor prognosis

Question 34

what is the most common site of metastasis?

Answer 34

the lung!!!!!!!!!

Question 35

what is the typical pattern of involvement in lung metastasis?

Answer 35

multiple nodules (cannonball lesions)

Question 36

classify small cell carcinoma

Answer 36

morphology

neuroendocrine differentiation by IHC

Question 37

classify squamous cell carcinoma

Answer 37

morphology
keratin production
squamous differentiation by IHC

Question 38

classify adenocarcinoma

Answer 38

morphology
mucin production
glandular differentiation by IHC