Breast Biopsy Mistakes Common
With the high rates of breast cancer in the United States, many women are aware that they are being told to see their gynecologist regularly and go for annual mammograms. And to reinforce that idea, they are told how wonderful mammography is and how it finds the majority of tumors and helps catch cancer at an earlier stage. But as we have explored before, the reality is somewhat less impressive. Studies have shown that yearly mammograms do not demonstrate a major impact on the reduction in breast cancer mortality. And now, to add fuel to the fire, new research has shown that the pathologists who specialize in analyzing biopsies often misdiagnose breast tissue.
The study, which took place at the University of Washington in Seattle, found that pathologists make mistakes in diagnosing abnormal, precancerous cells approximately half the time, which can result in overly aggressive treatment or lack of necessary treatment.1 The subjects were 115 American pathologists, who are medical doctors with specialty training that involves learning to analyze and diagnose biopsy samples. They assessed 240 specimens of breast tissue and made their diagnoses. The same samples were then evaluated by three expert diagnosticians and the results compared.
The pathologists were generally quite skilled at identifying the presence of invasive cancer in breast tissue, but had considerable trouble when the tissue sample was normal or showed signs of less obvious irregularities. Frighteningly, precancerous cells--which are abnormal cells that have a higher risk of becoming malignant--were only correctly identified in around 50 percent of the cases--equivalent to a coin toss. Approximately one-third of these tissue samples were incorrectly determined to be normal. This means the additional monitoring that generally enables cancerous changes to be found soon after they occur would not be recommended. The other 17 percent of the half of the precancerous samples that were mistakenly diagnosed were labeled as suspicious or malignant. That diagnosis could lead to an unnecessary treatment regimen including surgical removal of breast tissue and radiation.
Another condition the pathologists tended to misidentify was ductal carcinoma in situ (DCIS), which is a growth of abnormal cells within a milk duct. The results showed that 13 percent of the cases were deemed less serious, and another three percent were determined to be invasive cancer instead. This is not the first time this particular condition has been found to be difficult to diagnose, and in fact Jon Barron reported in 2010 about estimates that 17 percent of DCIS cases are misdiagnosed. And in the current study, the pathologists even found normal breast tissue to be suspicious in 13 percent of the specimens.
This is highly troubling since biopsies of breast tissue are extremely common, with an estimated 1.6 million taking place each year. These findings suggest that thousands of women may be undergoing surgery, having prophylactic mastectomies, or being subjected to physically harmful radiation for absolutely no reason at all. And at the same time, thousands of other women falsely believe they are healthy and and thus taking action when in reality they have abnormal cells or cancerous tissue multiplying inside them.
We do need to keep in mind that the research is not without flaws though. No follow-up was conducted to provide evidence that the findings of the expert panel were correct, so it is entirely possible that some mistakes were made by the "experts" as well. In addition, the participating pathologists had to make their diagnoses individually. In most laboratory settings, if a tissue sample is questionable and a pathologist is not completely certain of a diagnosis, he or she will typically confer with colleagues to establish a consensus.
But even if the reality is not quite as bad as the results of this study portray, it still serves as a scary reminder that mistakes are made often in healthcare and our lives can be at stake. And it should be remembered that it's not just one study, but a number of studies over the last few years that have called into question the reliability of breast exams. That's why it's essential to get a second opinion before undergoing any kind of potentially serious treatment or procedure. And it is also vital to pay attention to the signals your body is sending. If you don't feel right or something is hurting, don't ignore it because the doctor gave you a clean bill of health. Go to another physician and get retested so if there is a problem, you will catch it before it's too late.
- 1. Tanner, Lindsay. "Another reason for second opinion: Breast biopsies often misdiagnosed." Today. 17 March 2015. Accessed 25 March 2015. http://www.today.com/health/breast-biopsies-often-misdiagnosed-leading-wrong-treatment-some-2D80552849