MKSAP 19 "Quiz Me!" Question: Answer and Critique

Answer

B: Annual low-dose CT of the chest

Educational Objective

Screen for lung cancer in at-risk patients.

Critique

The most appropriate lung cancer screening strategy for this patient is annual low-dose CT of the chest (Option B). Smoking is the most important risk factor for the development of lung cancer, and risk increases with additional years of tobacco exposure and age. Lung cancer has a poor prognosis, and nearly 90% of persons with lung cancer die of the disease. However, early-stage non–small cell lung cancer has a better prognosis and can be treated with surgical resection. The U.S. Preventive Services Task Force guidelines recommend lung cancer screening with an annual low-dose CT scan for persons aged 50 years to 80 years with at least a 20-pack-year smoking history and who are still smoking or who quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery. Shared decision making, including providing patients with information about radiation exposure with CT, risk for false-positive diagnoses, and anxiety related to surveillance of slow-growing lung nodules, is a crucial element in making the decision to screen. Screening alone cannot prevent most lung cancer–related deaths, and smoking cessation is essential. This patient has a significant smoking history within the past 15 years and should be offered screening.

Chest radiography (Option A) is not an effective means of screening for lung cancer. Multiple studies have investigated chest radiography screening in patients at risk for lung cancer, and none has demonstrated a mortality benefit.

One-time screening with low-dose CT (Option C) is not the optimal strategy because continued annual screening is associated with the discovery of cancers that were not detected on the initial screen. Most guidelines recommend annual screening until at least the age of 74 years or until at least 15 years has passed since the patient quit smoking.

Not screening this patient for lung cancer is not the best strategy (Option D). Annual screening with low-dose CT in patients with a significant past or current smoking history results in a 20% to 24% reduction in lung cancer mortality.

Key Points

The U.S. Preventive Services Task Force recommends lung cancer screening with an annual low-dose CT of the chest for persons aged 50 years to 80 years with at least a 20-pack-year smoking history who are still smoking or who quit within the past 15 years.

Screening alone cannot prevent most lung cancer–related deaths, and smoking cessation is essential.

Bibliography

Krist AH, Davidson KW, Mangione CM, et al; US Preventive Services Task Force. Screening for lung cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325:962-70. PMID: 33687470 doi:10.1001/jama.2021.1117

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