What is an example of overdiagnosis risk in preventive screening?

• A. Detecting a cancer that would not progress, leading to unnecessary treatment and harm
• B. Missing a cancer that would progress
• C. Finding a disease with no treatment options
• D. Screening causing immediate cure

Answer: (A)

Overdiagnosis happens when screening finds a condition that would never cause symptoms or harm in a person’s lifetime, leading to unnecessary treatment and its harms. In cancer screening, some tumors are slow-growing or would not progress, so identifying them prompts surgery, radiation, or chemotherapy that the person didn’t actually need. Those interventions carry risks and side effects without real benefit, along with psychological and financial costs. This is why detecting a cancer that would not progress is the quintessential example of overdiagnosis. It’s different from missing a cancer that would progress, which is underdiagnosis, and from finding a disease with no treatment options or from expecting an immediate cure from screening, which aren’t about overdiagnosis in the same sense.