PATH: Pulmonary Neoplasia Flashcards
What types of neoplasms RARELY originate in the lung, and are not included in the definition of lung cancer?
Lymphomas and sarcomas
True or False: lung cancer is the most common cause o f cancer death and the US world-wide.
TRUE!
What is the major risk factor for lung cancer?
SMOKING (80% in active or former smokers)
What occupational hazard increases the risk of lung cancer 5 fold?
asbestos workers
What are KRAS, BRAF and PIK3CA ?
cytoplasmic signal transducer oncogenes that can be mutated in lung cancers
What are NKX2-1 (which codes for TTF1) and MYC?
nuclear DNA transcription oncogenes that are amplified in some lung cancers
What are CDKN2A (which codes for p16(INK4A), RB, TP53 and LKB1?
tumor suppressor genes mutated or deleted in some lung cancers
What is TTF1?
Thyroid transcription factor 1 (controls the expression of surfactant proteins and part of embryonic lung morphogenesis)–but has anti-oncogenic AND pro-oncoenic effects
What are the 3 major types of lung cancers?
1) Adenocarcinoma (40%)
2) Squamous cell carcinoma (20%)
3) Small cell lung cancer (15%)
In what epidemiological groups are adenocarcinomas becoming more comon?
Women, Young Patients (under 40), Asians, and never smokers
Where are adenocarcinomas most commonly found?
peripherally
What type of lung cancer is becoming less common?
squamous cell carcinomas
What are features of squamous cell carcinoma in the lung?
Central
commonly cavitate
commonly metastatic to local lymph nodes at presentation
cause post-obstructive pneumonia and hypercalcemia
True or false: small cell lung cancer is more commonly benign at presentation.
FALSE: >67% metastatic at presentation
What are some features of small cell lung cancer?
central
parabronchial
associated with paraneoplastic syndrome of inappropriate antidiuretic hormone, Cushing syndrome, or Eaton-Lambert syndrome
What is the average age for lung cancer symptoms to present?
65-74
What are the most common symptoms of lung neoplasms?
Cough (less common with adenocarcinoma because it is peripheral) Dyspnea Weight loss Hemoptysis Chest pain
How do you diagnose lung cancer?
STEP 1: Discovery via radiology (should screen 55-80 year olds with 30+ pack years of smoking with low dose CT)
STEP2: Actionable diagnosis with biopsy
What is the treatment for lung cancer?
NSCC:
- Surgery if low stage
- Adjuvant 2-agent chemo (1 plat based) if higher stage, large, or if lymph nodes involved
SCC:
Chemotherapy
If lung cancer is limited to chest and mediastinal lymph nodes, what is the treatment?
chemo and radiation
What is erlotinib?
targeted drug therapy for mutated EGFR
What is crizotinib?
targeted therapy for translocated ALK
What is the prognosis for lung cancer?
BAD: 5 year survival is 17%
What is a lung primary adenocarcinoma?
malignant epithelial tumor of lung with glandular features such as making glands or mucin
Why has the incidence of filter cigarettes increased the amount of adenocarcinomas?
filter removes large particles but forces smoker to inhale deeper, so small particles get deposited in small airways
Which type of adenocarcinoma has an EFGR-dependent pathway?
adenocarcinoma in never-smokers
Which type of adenocarcinoma has an KRAS-dependent signaling pathway?
adenocarcinoma in smokers
this is way less common than the EFGR mutation!
True or false: the only way to become resistant to erlotinib is to have a mutation to EGRF?
FALSE: if KRAS is mutated (downstream), you will also get resistance (KRAS mutation is slightly more common than EGFR mutation)
What is the consequence of an EML4-ALK translocation fusion oncogene?
has potent oncogenic activity and confers resistance to crizotinib
Which tumor suppressor gene is mutated in 60-70% of adenocarcinomas?
p53
True or false: adenocarcinomas are the most likely lung cancer to respond to targeted therapy.
TRUE
Describe the gross pathology of adenocarcinomas.
Peripheral Subpleural < 4 cm Solitary and solid may have demoplastic reaction (scar)
What are the 5 microscopic patterns of adenocarcinoma?
Acinar Papillary Micropapillary Solid Lepidic
Which is the most common microscopic pattern of adenocarcinoma? What are its features?
acinar (makes glands and has demoplastic rxn)
Which microscopic pattern of adenocarcinoma has a good prognosis?
lepidic- spreads within alveoli (commonly a single cellular layer) without invading (adenocarcinoma in situ)
What two patterns of adenocarcinoma have bad prognoses?
Micropapillary
Solid
What are the most common symptoms of adenocarcnoma?
cough (50%), weight loss (40%), hemoptysis (25%), dyspnea (25%), chest pain (20%, usually dull and persistent)
Which pulmonary neoplasms are typically Napsin A, CK7, and TTF1 positive, but RARELY CK5/6 or p40 positive?
adenocarcinoma
Which pulmonary neoplasms are typically p40, p63, and CK5/6 positive but rarely TTF1 or Napsin A positive?
squamous cell carcinoma
What is the treatment for adenocarcinoma?
surgical resection (option only for low stage)
erlotinib (if have EGFR mutation)
crizotinib (if have ALK translocation)
IF INOPERABLE: radiation and double-agent cytotoxic chemotherapy
What is the first agent used in chemotherapy of adenocarcinomas?
DNA-cross-linking platinum salt (cisplatin or carboplatin)