Misdiagnosed Cancer Not Uncommon

May 8 -- For Frank Barerra, the memory is haunting. He was 48 years old when he was diagnosed with prostate cancer. He was about to have his prostate removed. The surgery was just minutes away: The IV drip had begun, the operating room was set.

And then the call came in from the pathology department. A check of his biopsy slides showed there had been a mistake. There was no cancer.

"You can imagine it was like waking up from a bad dream," Barerra recalls.

And these mistakes happen more often than many people might realize.

Study Found Many Mistakes

Some 1.3 million people are diagnosed with cancer every year. The person making the diagnosis is usually a pathologist who has analyzed the patient's tissue in a lab, but has never met the patient in person.

When researchers at The Johns Hopkins Hospital in Baltimore reviewed tissue samples from 6,000 cancer patients across the country, they found one out of every 71 cases was misdiagnosed; for example, a biopsy was labeled cancerous when it was not. And up to one out of five cancer cases was misclassified.

Misjudging how fast or how far the cancer had spread could dramatically affect a patient's care.

"That can change whether a patient gets no treatment, vs. surgery, vs. radiation," says Dr. Jonathan Epstein of The Johns Hopkins Hospital. "If they get surgery or radiation, which type?"

Get a Second Opinion From an Expert Pathologist

Mistakes can occur on any biopsy, but especially tissue from the skin, prostate, breast and female reproductive tract.

"We really still make the diagnosis pretty much the way we did for the last 50 years," says Dr. Leonard Zwelling of the MD Anderson Cancer Center. "It has to come down to looking at a piece of the tumor on a slide by a pathologist."

But what type of pathologist? Many are not specialists in the type of cancer they're trying to diagnose.

It becomes a problem when trying to decipher a biopsy slide. When one pathologist took a look at a slide, he saw prostate cancer. It had many of the classic features, including a small cluster of cells crowded together. But other pathologists — experts in prostate cancer — looked more closely at the individual cells and discovered they were harmless.