Ask a doctor how often they misdiagnose cancer and most will tell you 0% to 10% of the time; however, multiple studies estimate general instances of cancer misdiagnosis to be as high as 28%.1

This observation is an important takeaway from a new survey titled “Exploring Diagnostic Accuracy in Cancer: A Nationwide Survey of 400 Leading Cancer Specialists”. The survey was conducted by the National Coalition on Health Care (NCHC) and Best Doctors, Inc., and reveals that oncologists significantly underestimate how often they incorrectly diagnose cancer in patients, said Larry McNeely, Policy Director for the NCHC in Washington, D.C.

“It’s really startling to see doctors underestimate the frequency of their misdiagnoses,” said McNeely. “Any misdiagnosis, even just one time, is too frequent. So cancer misdiagnosis is a bigger problem than most recognize.”

Related: Doctors’ Confidence About Diagnosis Unrelated to Diagnostic Accuracy

Over 60% of physicians participating in the survey placed themselves in the 0%-to-10% range for instances of cancer misdiagnosis or incomplete characterization of the disease. A third of the participants estimated they misdiagnosed cancer between 10% and 20% of the time, while 4.8% estimated their error rate to be 20% to 30%. No physician taking part in the survey estimated making cancer diagnostic errors more than 40% of the time.1

Top 5 Misdiagnosed Cancer Conditions1

Physicians taking part in the NCHC/Best Doctors survey named 21 cancers most often misdiagnosed or mischaracterized. Five led the list by a considerable margin:

  1. Lymphoma
  2. Breast Cancer
  3. Sarcomas
  4. Melanoma
  5. Cancer of Unknown Primary Site

Studies of specific forms of cancer have reported even higher rates of misdiagnosis. Radiologists who determined their patients needed a biopsy for breast cancer reported mammography errors as high as 75%.2  

Oncologists screening for lung cancer reported missing cancerous lesions in chest x-rays as much as 71% of the time, with the patient’s clavicle getting in the way of a clear x-ray 22% of the time.2 

In fact, there are instances when diseases are just plain missed, evidenced by the finding that one in 10 autopsies reveals a condition of full blown-disease that would have affected the patient’s care when they were alive.3

Physicians participating in the survey were asked to rate factors they felt would help reduce error when diagnosing cancer. These factors included:

  • Less fragmented or missing patient information (38.5%)
  • New or improved pathology tools or resources (36%)
  • New or more readily accessible resources for genetic testing of tumors (17.8%)
  • New or improved radiology tools and resources (15%)
  • Nationally integrated electronic medical records (EMRs; 14%)
  • Increased availability of remote consultations (11%)
  • Computerized decision support tools (6.3%)

A Case in Point

A large number of physicians surveyed said improved pathology interpretation would decrease instances of cancer misdiagnosis.1 Earlier studies have concluded that errors in reading pathology samples can be as high as 51%.1 Errors in misreading pathology reports can cause substantial issues, as noted in the case of Eva Grayzel.

In 1996, Eva Grayzel, a 48-year-old woman from Allentown, PA, had an oral surgeon remove a sore from the left side of her tongue, which came up negative for cancer after being sent to pathology. Two years later the sore returned in the exact same place. Grayzel’s dentist diagnosed hyperkeratosis and shaved down Grayzel’s molars in hopes of easing friction against her tongue, but this did not solve the problem of the painful sore. Soon, Grayzel was suffering ear aches that her general practitioner diagnosed as being caused by water in the ear, while a second oral surgeon simultaneously had Grayzel fit with a dental night guard to prevent her from biting her tongue as she slept. 

“At this point I began to feel like doctors were just guessing about what was wrong with me,” Grayzel recalls. “I was too worried about my health to go back and try and question my dentists and doctors, and I felt like I was being a nuisance.”

Grayzel sought other options and waited a month to be seen at Mt. Sinai Medical Center in New York, NY. “As soon as Mt. Sinai doctors saw my tongue and the bulge coming from my neck they ordered a biopsy,” Grayzel recalled. Within hours after showing up to her first appointment at Mt. Sinai, Grayzel was told she had stage 4 cancer, and was immediately scheduled for surgery and chemotherapy.

Surgeons removed part of Grayzel’s tongue and upper lymph nodes, reconstructed her tongue using tissue from her right arm and leg, and took a portion of an artery from Grayzel’s left arm to feed blood to the reconstructed tongue. Subsequently, Grayzel sued the dentist who diagnosed hyperkeratosis and won because the dentist had altered his notes.

The oral surgeon who misdiagnosed Grayzel’s early pathology results settled with Grayzel out of court because the biopsy sample was over 2 years old. Grayzel’s pathologist defended herself saying that any dysplasia discovered in Grayzel’s mouth was not serious enough to be reported in medical records, but then she backed off and settled the case out of court as well.

“I was angry,” said Grayzel. “None of my early doctors ever seemed to communicate with each other in a way that addressed one single problem. Every time it was ‘OK, we wonder what this is this time’.”