Wk 6 Lung Cancer Flashcards
What % of lung cancers occurs in smokers?
85%
What are 2 primary mutagenic components of cigarette smoke?
- polycyclic aromatic hydrocarbons
- arsenic (increases risk of squamous cell carcinoma in lung)
Major cause of mesothelioma
asbestos
2 major types of lung cancer
- small cell carcinoma (SCLC)
- non-small cell lung cancer (NSCLC) - 85%
3 types of NSCLC
- adenocarcinoma - most common
- squamous cell carcinoma
- large cell carcinoma (less common)
What is the most common lung cancer of non-smokers?
adenocarcinoma 40-50% of lung cancers
-most common lung cancer in women (women>men)
-still associated w/ smoking
-peripheral
What mutations are seen in adenocarcinomas?
EGFR
KRAS
ALK
What are the 4 C’s for squamous cell carcinoma?
Centrally located
Cigarettes
Cavitary
Calcium abnormalities
Must have:
1. “squamous/keratin pearls”
-best prognosis
2. intercellular bridges (desmosomes)
-may produce PTHrP
What lung cancer has the worst prognosis?
Small cell carcinoma
S’s of small cell carcinoma
“Sentrally” located
Smoking
Suck - worst px
Syndromes (paraneoplastic like Lambert-Eaton syndrome, Cushing, SIADH)
Simple Staging
-often presents w/ something different - quickly invades lymphatics, BVs
-metastatic to brain, bone, liver
Clinic presentation for SCC
pulm symptoms
incidental finding on imaging
metastatic lesion complications - nausea, weakness
-paraneoplastic syndromes
acronym for SCC
SPHERE:
SVC syndrome
Pancoast tumor
Horner’s syndrome
Endocrine abnormalities
Recurrent laryngeal nerve dysfxn -> hoarseness
Effusions
Endocrine abnormalities and associated lung cancers
Most common adenocarcinoma mutation
EGFR
Genetic mutations in lung cancer
Dominant oncogenes: Ras, HER2/neu, C-myc, C-fos
Tumor Suppressor genes: p53, Rb, p16
What are 3 risks of lung cancer screening?
- false positives
- potential overdx for findings that may not have caused problems
- radiation exposure from repeated LDCT tests
What are the 5 main types of lung cancer?
- small cell carcinoma
- adenocarcinoma (NSCLC)
- squamous cell carcinoma (NSCLC)
- large cell carcinoma (NSCLC)
- Carcinoid tumor (NSCLC)
What is a pro-carcinogen?
Must be metabolized to become a carcinogen
What is a ferrugenous body?
Asbestos fiber w/ macrophages on it
seen in mesothelioma
What cancer is associated w/ asbestos?
Lung cancer first, mesothelioma second
What is needed for dx of lung cancer?
biopsy
What are 2 benign lung lesions?
- granuloma - can present as a coin lesion, often due to TB or fungus
- bronchial hamartoma (tissue that belongs in that area but is disorganized) - contains lung tissue and cartilage, often calcified on imaging
Distinguishing differences b/w tx of small cell carcinoma and NSCC
- small cell - surgical resection does not work, but does for NSCC
- small cell tx w/ chemotherapy, NSCC usually does not respond well to chemo
What are 2 key histological indicators of adenocarcinoma?
- glands
- mucin production
2 key histological findings for squamous cell carcinoma
- keratin pearls
- intercellular bridges
Characteristics of large cell carcinoma
Smoking
-poorly differentiated large cells
-central or peripheral
-poor px
Characteristics of bronchioalveolar carcinoma
-columnar cells that grow along preexisting bronchioles and alveoli
-arise from Clara cells
- not related to smoking
- peripheral
- can present like pneumonia-like consolidation
- excellent px
Characteristics of carcinoid tumor
Well differentiated neuroendocrine cells (compare to SCC, which is poorly differentiated neuroendocrine tumor)
-chromogranin positive
-not related to smoking
-often polyp-like mass in bronchus, central or peripheral
-low-grade malignancy
-rarely, but can cause carcinoid syndrome
Describe histology of carcinoid tumor
What does chromogranin + look like w/ carcinoid tumor?
Stains positive b/c it’s a neuroendocrine type tumor
What are the most common types of metastasis to the lung?
breast and colon carcinoma
What does metastasis to the lungs look like?
multiple cannonball nodules on imaging
-more common than primary tumor
How is lung staging done?
TNM:
T: size and local extension of tumor
N: spread ot regional lymph nodes (hilar or mediastinal)
M: unique site of distant spread is the adrenal gland
-overall, 15% 5 yr survival
What are 4 local complications w/ lung cancer?
- pleural involvement
- SVC obstruction (SVC syndrome)
- involvement of laryngeal (hoarseness) or phrenic nerve (diaphragmatic paralysis)
- compression of sympathetic chain (ptosis, meiosis, anhidrosis - Horner’s Syndrome) - esp w/ Pancos tumor (at the apex of the lung)
What cells line the visceral and parietal pleura?
mesothelial cells - produce fluid in pleural space
Characteristics of mesothelioma
=malignant neoplasm of mesothelial cells in pleural space
-assoc w/ asbestos exposure
-presents w/ recurrent pleural effusions, dyspnea, and chest pain
-tumor encases the lung
Label the cancers
A. carcinoid tumor
B. squamous cell carcinoma
C. small cell carcinoma
D. adenocarcinoma
