Can a cancer diagnosis ever be wrong?

The article was professionally consulted by a Doctor of Oncology Center, Vinmec Central Park International General Hospital.

Cancer is emerging as one of the most common and feared diseases because there are many types of cancer for which medicine has not yet found a cure. For many people, being told cancer is like being sentenced to death. Most of them are healthy and show no signs of illness; so they always feel it's not right. A good question to ask doctors in these situations is, “Is the cancer diagnosis wrong?”

In fact, people who have just received the news that they have cancer - have a right to hope because medical events or anything else in the world will never be true with 100% probability. Therefore, the diagnosis of cancer can also be wrong, even if this happens very rarely.
It is estimated that more than 1.3 million people are newly diagnosed with cancer every year. Diagnosis of cancer before informing the patient always requires a pathological examination. The treating doctor will take a small sample of tissue from a suspected tumor and send it to pathology testing.
A pathologist who specializes in examining the nature of the tumor under the microscope will answer the results based on very strict criteria. Pathology is the decisive factor, also known as the "gold standard" in cancer diagnosis. However, it is necessary to have coordination from the treating doctor to supplement information from disease progression, examination, ultrasound, CT, MRI, and blood tests... to make a final conclusion.

A study at Johns Hopkins Hospital in the US found that 1 in 71 cancer diagnoses was misdiagnosed. This can happen at the stage of pathology - when the pathologist only examines the image of the tumor sample without the patient's medical information.
In addition, this result may also be wrong in cases where the cancer is located deep in the body (eg liver cancer, lung cancer...), it is difficult to get a small sample for testing. These tumors also make it difficult for treating doctors to examine; At that time, the diagnosis was mainly based on the test results. Usually, based on scans and tests alone, the likelihood of a cancer misdiagnosis is higher than it is on pathology. In some situations, the atypical presentation of the cancer also makes the diagnosis difficult.
However, as mentioned above, cancer diagnosis is always a combination of many steps, many doctors to come to a final conclusion for the patient. A misdiagnosis of “not sick to sick” can expose a healthy person to some unnecessary treatment. After that, though, the diagnosis will be revised and updated throughout the course of treatment.

Misdiagnosis of cancer with the word “failure to have disease” is the most common mistake. There are also cases where the disease is diagnosed as benign or simply undetected. This often happens with early cancer cases, there are no symptoms and patients often go for regular health check-ups or undergo cancer screening. In this situation, the diagnosis of cancer is mainly based on test results, which are never 100% correct. Medical researchers are constantly trying to improve this because missed cases will delay treatment, affecting the ability to cure.
Another common misdiagnosis of cancer is to misjudge the spread of the disease (stage of the disease), thereby affecting treatment. The study at the Johns Hopskin Hospital mentioned above has shown that 20% of patients with cancer fall into this category.
Indeed, diagnosing the stage of cancer is not easy. This is a meticulous and detailed process that requires a lot of information from the patient's medical condition, from the tumor, from the lymph nodes, from the liver, lungs, bones, brain, and other organs. This process often requires tests, which can sometimes lead to mistakes.
The stage of the disease greatly affects the way of treatment, so it is necessary to have a multi-specialty board (Tumor board) to review the diagnosis, the stage before treating the patient. The multidisciplinary panel usually includes an oncologist, surgeon, radiologist, pathologist, and other relevant professionals who sit together. To have such a committee requires a lot of effort and solidarity among doctors as well as time and work arrangement. A cancer center only needs to have more than 15% of the patients approved by the board each year to meet one of the strict COC (Commission on Cancer) standards of the United States. That said, not all patients are approved by the panel, unless there is some difficulty in diagnosis or treatment.
Misdiagnosis in cancer in particular or medicine in general is always a concern of doctors because it affects not only patients but also themselves. Doctors always try to improve their professional knowledge, improve their ability to cooperate with each other as well as update medical knowledge to try to improve the accuracy rate of tests with the aim of reducing the rate. this rate to the lowest possible level.
If you or a loved one have concerns about your diagnosis, stage of disease, or treatment plan, you can contact us for further advice. In some complicated cases, you can go through the Tumor board of Vinmec to make recommendations from experts in the field of oncology.