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Overdiagnosis and Preventative Screening: A Q&A With Ilana Richman

November 14, 2023

Ilana Richman, MD, MHS, assistant professor of medicine (general internal medicine), is a general internist and health services researcher. She investigates the use, effectiveness, and value of preventive services. She has a specific interest in cancer screening, and her current research focuses on evaluating new breast cancer screening technologies as well as the use and implementation of lung cancer screening.

In a Q&A, Richman discusses why overdiagnosis is a concern, the challenges of assessing the benefit of new screening technologies, and the risks and benefits people should weigh when considering preventative screening.

How did you first become interested in studying the use, effectiveness, and value of preventative services?

When I was a medical resident, a paper came out about breast cancer overdiagnosis after screening. At the time, the idea that screening could be both helpful and harmful struck me as surprising and counterintuitive. It was an idea that I hadn’t been taught in medical school.

We’re used to thinking of screening as being important and something that everyone should do. There is a benefit and value to screening, but there are also trade-offs.

What is overdiagnosis, and why should we be concerned about it?

Overdiagnosis refers to the situation in which we find a disease that wouldn’t have been clinically apparent if we hadn’t gone looking for it. In other words, the person diagnosed never would have developed symptoms or died from the condition.

Overdiagnosis is a concern because we end up treating some fraction of people for something that never would have impacted their health. And some treatments—such as surgery, radiation, and chemotherapy—are intense.

How does new technology impact overdiagnosis? Can you give a specific example?

Mammography, for example, has a long history. It became popular in the 1980s when we were using film mammography. And then in the late 90s, we transitioned to digital. In the last seven years or so, we’ve switched to a newer technology called 3D mammography, sometimes called digital breast tomosynthesis. We’ve also started using ultrasound, MRI, and computer-aided detection with new AI algorithms.

When new technologies are introduced, it’s challenging to figure out whether they’re helping, they’re neutral, or they’re producing harm. It’s difficult to draw strong conclusions because we need a long period of follow-up, which we don’t yet have with new technologies.

What are the risks and benefits people should weigh when considering preventative screening?

For several types of cancer screening—like breast, colorectal, cervical, lung, and to some extent, prostate—we have clear guidance about who’s likely to benefit and what the magnitude of those benefits are. Those tests are generally supported by evidence, meaning that people are more likely to benefit than be harmed. But every individual is different, and making a decision about screening depends on risk factors for not only cancer but also other health conditions that might affect a person’s likelihood of benefiting.

Different screening tests have different trade-offs. For example, one of the most common downsides to breast cancer screening is being called back for abnormal mammograms that turn out to be nothing to worry about. Whether that matters to someone depends on who they are, what that experience is like to them, and how they perceive the benefit of the screening.

In addition, the risk of overdiagnosis changes with age, health, and life expectancy, becoming more relevant for older people. The shorter a person’s life expectancy is, the more likely that any cancer found wouldn’t be clinically apparent in that person’s lifetime.

I would advise that people talk with their primary care doctor about which screenings they might be eligible for and what the trade-offs of those screenings are.

General Internal Medicine is committed to the core missions of patient care, research, education, and community health from the “generalist” perspective and is one of the 11 sections within Yale School of Medicine’s Department of Internal Medicine. To learn more about their mission and work, visit General Internal Medicine.

Submitted by Serena Crawford on November 13, 2023