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September was Prostate and Thyroid Cancer Awareness Month, October was Breast Cancer Awareness Month, and November was Lung Cancer Awareness Month. We should designate December as Cancer Overdiagnosis Awareness month, because a lot of cancers diagnosed by screening tests will never kill you.

Through decades of advocacy by patients, family members, and doctors, the public has never been more aware of the dangers of slow-growing, yet sometimes deadly cancers like thyroid, breast, and prostate cancer. Newer, more sensitive tests are promoted to encourage early detection and treatment. These interventions, it is said, “save lives.”

Undoubtedly some lives have been saved by the increased early detection and treatment of symptomless cancers. Yet there is another side: the problem of overdiagnosis. That’s when doctors diagnose a disease that won’t cause the death of a patient during the patient’s lifetime. And it is a complicated problem: Many diagnoses and treatments doctors provide today simultaneously have the ability to be either life-saving or unnecessary but nonetheless life-altering.

Overdiagnosis is something physicians are increasingly concerned about. It’s time for a frank public discussion because we, as doctors, will never be able to address overdiagnosis without the input of the patients we serve.


One recent example is actor Ben Stiller’s announcement that a PSA blood test had resulted in his being diagnosed and treated for symptomless prostate cancer. The actor made a clear-cut declaration the test had saved his life. In truth, the situation is more nuanced. Prostate cancer is included among cancers frequently overdiagnosed since most people with symptomless prostate cancer will never be harmed by it. But the unnecessary diagnosis and treatment will produce unwanted symptoms, as well as psychological and social consequences. The experience will be life-altering but not life-saving for all patients and their loved ones.


How can something as terrible as cancer occur without causing symptoms or death? The final definitive diagnosis of cancer is rendered by pathologists, like us, after a doctor takes a tissue sample, a biopsy. We examine the tissue under a microscope and may detect certain features that lead us to believe these cells are malignant. We often perform additional tests to confirm malignancy.

What pathologists do is high-tech and scientific but not clairvoyant. When we make a diagnosis of cancer, we are suggesting the cells we are seeing have the possibility to grow, spread, and hurt the patient, even take a life. But a possibility is not a certainty. We are still imperfect fortune-tellers.

Even when a pathologist correctly diagnoses cancer, doctors know cancers can behave with varying degrees of aggressiveness. The degree of a cancer’s aggressiveness cannot be perfectly predicted for each patient, so doctors will typically treat most cancers. Better safe than sorry, goes the reasoning.

However, through advancements in technology, we have come to know that what pathologists call “cancer” is far more prevalent than we could have imagined. A large number of people are living with cancers inside their body that will never harm them because they will grow very slowly and may not spread.

For example, the number of people diagnosed with thyroid cancer has more than tripled since 1975, yet the number of people dying of it hasn’t changed at all. How is this possible? The simple answer is many healthy people have small harmless cancers within their thyroids that we have gotten very good at spotting with newer high-resolution imaging technology. And since we practice better-safe-than-sorry medicine, we treat them all.


But healthy people’s thyroids contained these small symptomless cancers before CT scans and ultrasounds were invented. Even when we couldn’t spot and treat these cancers, most people never suffered from any problems related to these tumors. This has led doctors and patients to face a hard reality: Treating small thyroid cancers doesn’t often save lives because they aren’t life-threatening to begin with. To be sure, treatment is helpful in some patients, but all must risk complications such as injury to nerves and salivary glands, and many must take thyroid hormones for life.

Doctors are struggling with what to do. When should we treat these small cancers? When do the risks of treatment outweigh the benefits? Is safe always better than sorry?

The American Thyroid Association has recently published guidelines against overdiagnosing and overtreating small, symptomless cancers. But this is not a decision for physicians alone; patients must participate, too. Yet, it is hard to have an honest, nuanced discussion take place when myriad awareness months instill the fear of death in patients. Shouldn’t people also hear about the cancers that will never hurt them?

Pathologist Elliott Foucar notes that there are many “diagnosis survivors who are mistakenly regarded as cancer survivors.” They are survivors of ultra-sensitive screening techniques that diagnosed small cancers that were not lethal. We believe these survivors need their own public awareness campaign to foster a conversation about unnecessary diagnosis. Some diagnosis survivors may feel relief. Others may feel anger because they received potentially unnecessary treatments. But through the regular, public conversation that awareness brings, doctors and patients can better participate in a shared decision-making process.


Benjamin Mazer is a resident physician at Yale-New Haven Hospital. Manju Prasad is a professor of pathology at the Yale School of Medicine and a Public Voices Fellow.