9/17- Clinical Presentations of Lung Cancer Flashcards
What are some primary tumors of the lung?
Other lung malignancies (non-lung parenchyma cells)?
- Squamous cell
- Adenocarcinoma
- Large cell
- Small cell
- Other
Other lung malignancies:
- Mesothelioma
- Sarcoma
- Lymphoma
- Lung cancer is the __ most diagnosed cancer in men and __ in women.
- In terms of mortality, lung cancer is the __ most fatal cancer in men and __ in women
- Lung cancer is the 2nd most diagnosed cancer in men and 2nd in women.
- In terms of mortality, lung cancer is the #1 most fatal cancer in men and #1 in women
T/F: Lung cancer kills more people than breast, colorectal, and prostate cancer combined
True
- Smokers are __x more likely to develop lung cancer
- Passive exposure?
- Over __% of lung cancer is related to smoking
- Smokers are 13x more likely to develop lung cancer
- Passive exposure: 1.5x greater
- Over 90% of lung cancer is related to smoking
- Risk is decreased when you stop smoking, but takes about 20 years to come near the same level as non-smoker
The risk of cancer is proportional to what smoking factors?
- Number of pack years
- Age at starting
- Depth of inhalation
- Amount of tar
- Less risk with cigars/pipes
- Quitting decreases your risk (20 years to come near non-smoker, but never equal)
T/F: Smoking rates have stabilized in the US (no more increases)
False
- Smoking is decreasing in the US
T/F: There are more male smokers than female
False
- About 24% of women and 23% of men (currently)
What population has the greatest percentage of smokers?
Adolescents
- Minorities and youth
- Increasing problem in 3rd world countries
What are non-smoking risk factors for cancer (occupational carcinogens)?
What proportion of lung cancers are due to these occupational exposures?
9-15% of lung cancers are due to occupational exposures
- Asbestos
- Arsenic
- Bis(cholormethyl)ether
- Chromium
- Coke oven emissions
- Iron and steel founding
- Mustard gas
- Nickel compounds
- Radiation
- Vinyl chloride
Suspected (not proven):
- Be
- Cd
- Crystalline silica
- Fibrous glass
- Formaldehyde
- Welding fumes
When is the peak incidence for asbestos-related cancer?
Peak 30-35 years after initial exposure
T/F: The risks of smoking and asbestos exposure is additive
False; multiplicative (not just independent)
What are other environmental risk factors for lung cancer?
Air pollution
- Indoor air pollution (developing world with cooking fuels): as bad as smoking!
- Atmospheric air pollution: urban effect (weak association)
Radiation
- Radiation that is a risk for lung cancer is the high-dose stuff involved in atomic bomb… not really x-rays and whatnot
What diets may effect lung cancer development?
Diet high in antioxidant nutrients may protect against oxidative DNA damage and protect against cancer
- Weak evidence showing protection with high fruit intake; better with increased veggies
- Dietary retinol may reduce risk
- Better evidence for carotenoids and vitamin C (Need to take them in naturally, not supplements)
Why do a minority of exposed persons with the mentioned environmental agents not get lung cancer?
Host factors
- Familial aggregation seen in case-control studies after being controlled for smoking
- Genetic factors may play a role in many stages of the multi-stage model of lung cancer development
- Previous acquired lung diseases: COPD and fibrotic lung disease (asbestosis)
Explain how lung cancer is a “multi-hit” problem
Body has many natural protective factors; tumor development requires:
- Persistence/miscoding
- Activation of dominant oncogenes
- Inactivation of tumor suppressors
What are the big (2) divisions of lung cancer types?
Subtypes? Percentages?
Non-small cell carcinomas ~ 70% (other lecture said 80%)
- Squamous
- Adenocarcinoma
- Large cell
Small cell carcinoma ~25% (other lecture said 20%): aka “oat-cell”
When is lung cancer commonly discovered? Peak?
- Majority between 35-75 years
- Peak = 60 yo
- 5-15% asymptomatic at diagnosis (detected through screening or incidentally by imaging done for other reasons)
T/F: Lung cancer normally presents like other diseases (non-specifically) with things like dyspnea, cough…
False; commonly asymptomatic
What is a solitary pulmonary nodule?
- Solitary pulmonary nodule = “coin lesion”
- Spherical mass surrounded by lung parenchyma
What is the differential for a solitary pulmonary nodule (SPN)?
- Malignant
- Benign
Large differential (benign -> malignant)
Malignant:
- Bronchogenic cancer
- Metastasis: breast, head/neck, colon, kidney, germ cell
- Bronchial carcinoid
- Other
Benign:
- Infectious granuloma: TB, Histo, Cocci
- Hamartoma
- Wegener’s
- Rheumatoid nodule
- A-V malformation
- Pulmonary infarction
What are certain features of solitary pulmonary nodules that help distinguish between benign and malignant?
More commonly malignant if:
- Very large
- Irregular margin
- Intermediate doubling time (30-490 days)
Less commonly malignant if:
- More calcified
- Fat present (hamartoma)
- Doubling time under 30 or > 490 days
What is seen here?
Benign nodule (probably… can’t depend only on appearance)
- Smooth boundary
- Calcification
What should be the next step for a mass found in a high risk patient?
Removal!
- Get diagnosis at the same time… but don’t waste time getting biopsy
What should be the next step for mass in intermediately-risky patient?
- Wait and watch
- Can do a PET scan (lights up metabolically active cells)
What are signs and symptoms of lung cancer (assuming pt isn’t asymptomatic)- broadly?
Constitutional symptoms: important prognostic implications regardless of “stage” of disease
- Weight loss (may be 1st seen)
- Fatigue
- Anorexia
- Weakness
What are some symptoms/signs related to primary tumor?
- Cough: most common
- Dyspnea: 60% of pts (so not too common; think, 2 cm tumor not affecting lung function too much)
- Hemoptysis: rarely severe (esp if peripheral tumor- not gonna happen)
- Wheeze and stridor (if obstructing airway)
- Post-obstructive pneumonia symptoms (pneumonia distal to tumor and cant clear, so pneumonia symptoms that persist)
- Chest discomfort: common, up to 50%, ill-defined
What are some signs/symptoms related to intrathoracic spread?
- Tracheal obstruction
- Dysphagia due to esophageal compression
- Hoarseness due to recurrent laryngeal nerve palsy; more on left side
- Phrenic nerve paralysis (elevated hemi-diaphragm and dyspnea)
- Sympathetic nerve paralysis (Horner syndrome)
- Pancoast syndrome
- Superior vena cava syndrome
What is Horner’s syndrome?
Symptoms/what causes it
- Involvement of sympathetic chain at the thoracic inlet at the apex of the lung
Syndrome:
- Enophthalmos
- Ipsilateral anhydrosis (no sympathetic innervation of sweat glands)
- Ptosis (droopy eyelid b/c sympathetics innervate superior tarsal muscle that elevate eyelid?)
- Miosis (constricted pupils; sympathetics normally work on dilator muscle to dilate eye)
What is Superior Vena Cava Syndrome? - Common cause - Mechanism - Signs/symptoms
Most common cause: lung cancer
Mechanism: compression of the thin walled vessel -> obstructed drainage of the upper thorax, head, and neck
Signs and symptoms:
- Swelling and plethora of the head and neck
- Distended venous collaterals
- Epistaxis
- Headache
- Confusion, and even coma
What is Pulmonary Hypertrophic Osteoarthropathy (PHO)?
Skeletal paraneoplastic syndrome
- Sub-periosteal new bone formation in distal joints/bones with edema and pain
What is seen here?
Mass way up in apex; Pancoast
What is seen here?
Looks like pneumonia
What is seen here?
- Pleural effusion
- Tumor encroaching into heart, mediastinum…
What is seen here?
PET scan
- Bright = high metabolic activity
- PET scan looks at entire body
