Being told that you have cancer is a terrible thing to hear. Each year, more than 1.7 million Americans will receive the diagnosis, and nearly 610,000 will die from it. And nearly 40 percent of Americans will be diagnosed with some type of cancer in their lifetime.

When I was in medical school in the late 1980s, we were taught that screening for cancer should be a priority because it led to better outcomes through interventions such as surgery, chemotherapy, and radiation.

But since then my thinking has changed, and over the years I have written repeatedly that many common cancer screening tests — such as mammograms and prostate-specific antigen (PSA) blood testing — are overhyped.

Yes, the tests can detect a cancer at an early stage. But early detection does not always result in a longer life span.

Furthermore, many of the medical therapies that are used to treat cancer — including chemotherapy, radiation, and surgery — are very expensive and associated with serious adverse effects.

For a screening test to be useful, it should not only be able to diagnose a disease at an early stage, it should be accompanied by a therapy that positively alters the course of the illness.

In the case of cancer, the early diagnosis and therapy should result in a significantly longer life span.