Smoking

Question 1

Pathophysiologic Effects of Smoking

Answer 1

Carcinogens (polycyclic aromatic hydrocarbons, nitrosamines) → DNA damage
• Chronic inflammation → oxidative stress, impaired mucociliary clearance
• Vasoconstriction + endothelial damage → ↑ atherosclerosis

Question 2

High-Yield Diseases Associated with Smoking

Answer 2

Cancers

Cancer
Clue in Vignette

Lung cancer
Most common cause overall; especially squamous cell & small cell

Bladder cancer
Painless hematuria

Pancreatic cancer
Weight loss + abdominal pain + smoking history

Head and neck cancers
Hoarseness, mass in neck/throat

Esophageal cancer
Especially squamous cell with alcohol

Tip: Smoking + hematuria = bladder cancer until proven otherwise.

Question 3

Respiratory Diseases

Answer 3

• Chronic bronchitis (productive cough >3 months/year for 2 years)
• Emphysema (centriacinar – affects upper lobes)
• COPD (chronic bronchitis + emphysema)
• Bronchogenic carcinoma (especially squamous cell and small cell types)

Tip: Smoking = most important risk factor for both COPD and lung cancer. Centriacinar emphysema = smoking; panacinar = A1AT deficiency.

Question 4

Cardiovascular Diseases

Answer 4

• Coronary artery disease (CAD)
• Peripheral artery disease (PAD)
• Aortic aneurysm (especially abdominal)
• Stroke

Tip: Smoking + claudication = PAD; look for “decreased pulses and bruits”.

Question 5

Obstetric Risks

Answer 5

• Intrauterine growth restriction (IUGR)
• Placental abruption
• Preterm labor
• Low birth weight
• Sudden infant death syndrome (SIDS)

Tip: Smoking = vasoconstriction of placental vessels → impaired fetal oxygenation.

Question 6

GI & Hepatic Risks

Answer 6

• Peptic ulcer disease (↑ H. pylori virulence, ↓ mucosal protection)
• Pancreatitis and pancreatic cancer
• Hepatic steatosis (indirect effect via metabolic syndrome)

Question 7

Specific Lung Cancer Associations

Answer 7

Histology
Smoking Link
Key Features

Squamous cell
Strong
Central, cavitation, hypercalcemia (PTHrP)

Small cell
Strong
Central, neuroendocrine, paraneoplastic syndromes (ACTH, SIADH)

Adenocarcinoma
Weak
Peripheral, most common in non-smokers and females

Large cell
Moderate
Peripheral, anaplastic, poor prognosis

Tip: “Central lung mass + paraneoplastic syndrome” = small cell carcinoma.

Question 8

Immunologic & Other Effects

Answer 8

↓ Macrophage function
• ↓ Ciliary action
• ↑ Risk of infections (especially pneumonia, influenza)

Tip: Smokers with COPD often get H. influenzae, Moraxella, and Strep pneumo infections.

Question 9

Smoking + Alcohol = Synergistic Cancer Risk

Answer 9

Increases risk of esophageal squamous cell carcinoma and head/neck cancers

Question 10

USMLE Step 1 Tips

Answer 10

• When you see “smoker” in the vignette, immediately think:
• Lung or bladder cancer
• COPD/emphysema
• PAD, CAD, stroke
• Pancreatic cancer
• SIDS, low birth weight (if pregnant)
• Know which lung cancers are strongly linked to smoking and which are not
• Recognize that smoking is the most preventable cause of death in the U.S.