Lung tumors Flashcards
Tumors of the lung
Bronchogenic carcinoma: 90-95% originate in the brochial (or bronchiolar) epithelium
Carcinoids- 5%
Other tumors: 2-5%
Bronchogenic carcinoma, epidemiology
Most common cancer in the world, incidence is decreasing in men and increasing in women, 1/3 of cancer deaths in males >females, dramatic increase in women due to cigarette smoking
Lung cancer has surpaassed breast cancer as a cause of death in women
most frequent fatal malignancy in men and women
A disease of the middle life, <2% in people below 40
Tobacco smoking, industrial hazards, air pollution, molecular genetics, scarring
Bronchogenic carcinoma etiology and pathogenesis
Tobacco smoking,
Amount of daily smoking: smokers at 10x risk, heavy smoker at 20x greater risk, done smoke for 10 yrs back down to normal
Tendency to inhale, duration of smoking habit, duration of smoking habit. Pack year: a way to measure the amount a person has smoked over a long period of time, Multiply the number of packs per day by the mumber of years they smoke, 97% of smokers have atypical bronchial epithelium
Carcinogens: initiatiors and promotersm radioactive elements, contqminants, mice had skin tumors
Industrial hazards: radiation, uranium miners, asbestos without smoking 5x risk, asbestos w/ smoking 90x risk
Air pollution (radan)
Molecular genetics: C-myc (small cell carcinoma), K ras, EGFR, EML4 ALK- adenocarcinoma
Tumor suppressor genes: p53, RB, p16
Benzopyrene causes DNA damage at the same codons of the p53 gene, familial clustering and variable risk among heavy smokers
Scarring in bronchogeninc carcinoma
scar cancers- cancers occurring in the vicinity of pulmonary scars, usually adenocarcinomas, in most cases, the scar is a response to the tumor, sometimes scar precedes cancer
bronchogenic carcinoma clinical course and fearures
Usually present in their 50s, average duration of symptoms 7 months, major presenting complaints (cough, wt loss chest pain, dyspnea, increased sputum production (CYTOLOGY), may be diagnosed upon secondary spreas
pancoast tumor
tumor at the extreme apex of the lung, involvement of superior cervical sympathetic ganglion, Horners syndrome, ipsilateral lid lag, miosis, anhydrosis, (ptosis miosis and anhydrosis)
Bronchogenic carcinoma classification
Small cell carcinoma: oat cell (lymphocyte like), intermediate cell (polygonal), combined (usually with squamous)
Non small cell carcinoma: Squamous cell carcinoma, adenocarcinoma (glandular- acinar, with mucin), papillary, solid, lepidic bronchioloalveolar, Adenosquamous carcinoma
Large cell carcinoma: neuroendocrine, undifferentiated, giant cell, clear cell
Bronchogenic carcinoma classification based on chemotherapy response
Small cell carcinoma: senstitive to chemotherapy, surgery ineffective
Non small cell carcinoma: NSCLC subclassification used to not be important because of similar treatment strategy
Broncogenic carcinoma subtyping
Epidermal growth factor receptor (EGFR), KRAS, and ELM4-ALK mutations: confined to ADENOCARCINOMA, predictive of response (EGFR) and resistance (KRAAS), - erlotinib and gefitinib, ALK inhibitor (Crizotinib)
Bevacuzimab: Ab to VEGF, toxicity in SqCC (hemorrhage)
Pemetrexed: activity in non sqCc
Pembrolizumab: activity in non small cell carcinoma that express PDL1
Bronchogenic carcinoma: squamous cell carcinoma
the most common type in males, cigarette smoker, central cavitry necrosis, usually arise centrally (main or lobar bronchi) usually endobronchial, polypoid growth
Histology: Keratin formation, intercellular bridges, cellular atypia, invasion, differentiated subtypes
Adenocarcinoma- bronchogenic carcinoma
Most common type in women and non smokers (most patients with adenocarcinoma are smokers)
Most common form of lung cancer in USA
usually peripheral with pleural retraction or puckering, has scarring, grows slow and mets more frequently, often asymptomatic
Malignant epithelial tumor with glandular differentiation or mucin production
Histologic pattern: glandular (acinar with mucin), papillary, solid, lepidic (bronchioloalveolar
bronchioloalveolar carcinoma
a subset of adenocarcinoma
1-9% of all lung carcinomas
gross- single peripheral nodule, multiple nodules (several lobes/bilateral)- multifocal/aerogenous spread, diffuse pneumonia-like infiltrate
Histology: lepidic spread (tumor cells spread along alveolar septa), nonmucinous (clara cells, type 2 pneumocytes- 2/3 cases), mucinous tall columnar mucinous cells worse prognosis
Bronchogenic carcinoma: small cell carcinoma
20-25%, predominantly in males, high association with smokers, central location, highly malignant, median survival (4months)
Submucosal/cirumferential infiltration; rare endobronchial polypod growth
Subclassification: oat cell, intermediate cel, mixed (small/large cell) combined (small cell/adeno or awuamous)
Extensive necrosis, crush artifact, secretory granules of neuroendocrine type, IHC neuroendocrine markers (synaptophysin, chromogranin, CD56
Mets by the time of diagnosis; 70% pts seen at advanced stage
Ectoopic hormone production (paraneoplastic syndrome)
Responds to chemoradiation therapy
Bronchogenic carcinoma: large cell and giant cell
Large cell carcinoma, undifferentiated: pleomorphic, large cells without differentiation, may show ultrastructural evidenct of glandular or quamous differentiation, 5 yr survival 6%
Giant cell carcinoma: highly malignant, mostly peripheral, <10 month survival
Adenosquamous carcinoma
1-3% of lung carcinomas, definite evidence of squamous and adeno in the same neoplasm
Peripheral tumor, associated with scar,
Clinical presentation and behavior simlar to adenocarcinoma, majority of pts smokers
