Mammograms’ Reliability Under Question: Should This Be A Cause For Alarm?

Medical Malpractice Law & Strategy, Volume XVII, Number 3 January 1, 2000

By Robert A. Clifford

Recent research has cast doubts on the reliability of mammograms as a method of diagnosing breast cancer, giving the rise to concern among many women.

A mammogram is a low-dose X-ray that examines breast tissue, which helps the doctor diagnose various disorders of the breast. Each year, more than 20 million women in the United States receive mammography exams. One out of every eight women in the United States will develop breast cancer in her lifetime. That translates into breast cancer striking about 180,000 American women yearly, killing about 44,000, according to the American Cancer Society. It is second only to lung cancer in cancer-related deaths among women.

The smaller and more localized the cancer is at the time of diagnosis and treatment, the greater the likelihood of cure. The mammogram allows the detection of some types of breast cancer one to two years before a doctor or patient could feel it during an exam. Mammograms, however, are not 100 percent accurate, experiencing as high as a 20 percent error rate.

This error rate is due, in part, to equipment that is improperly maintained or personnel who are inadequately trained. Congress passed the Mammography Quality Standards Reauthorization Act (MQSA) in 1992 after realizing that poor-quality mammograms posed a serious health risk for women. The act’s primary objective is to ensure that mammography is safe and reliable and that breast cancer is detected in its most treatable stages. Prior to these federal regulations, quality standards varied from state to state.

The Food and Drug Administration has the responsibility for implementing and enforcing MQSA, which requires that all mammography facilities in the United States meet certain stringent quality standards; receive accreditation from an FDA-approved accreditation body, such as the American College of Radiology; and undergo inspection annually.

Despite the regulations, women who get regular mammograms to check for breast cancer still face an almost 50-50 chance of receiving one false alarm for every 10 tests, according to researchers. The New England Journal of Medicine published this new finding on April 16, 1998, which revealed the frequency of false-positive results to be twice the rate previously believed. Such false-positive results can lead to unnecessary surgeries, not to mention the psychological impact it can have on a woman.

Another quite controversial study, published in the Jan 7 issue of The Lancet medical journal, concluded, “There is no reliable evidence that screening decreases breast-cancer mortality.” It found fault with past clinical trials’ match-up of study groups and control groups. Others in the medical profession have denounced this study as itself unreliable.

A recent article in another top medical journal, though, reported that women have unrealistic expectations of the accuracy of breast cancer screening. In research published in the November 1999 Journal of Epidemiology and Community Health, a sample of 115 women, randomly selected from almost 3,000, took part in the National Breast Health Survey. A third of those sampled thought that screening should be realistically detect all breast cancers.

Conversely, though, just under half the women thought that financial compensation should be allowed for cancers missed by screening, even if this was a consequence of the small built-in failure rate. But if the cancer was missed as a result of medical negligence during the screening process, the figure jumped to 93 percent. The survey also demonstrated that younger, more urban women and those with more realistic expectations of breast cancer screening were more likely to favor financial compensation.

Failure to Diagnosis

A top radiologist in Chicago, Dr. Leonard Berlin, chairman of radiology at Rush-Presbyterian St. Luke’s Medical Center, opined in the January issue of the American Journal of Roentgenology that “the number of medical malpractice lawsuits alleging injury due to missing or delaying the diagnosis of breast cancer has increased so rapidly that such lawsuits have now reached epidemic proportions.” But how many of the lawsuits are the result of the radiologist’s negligence? Dr. Berlin is not willing to speculate on the legitimacy of the allegations in any lawsuit. And failure-to-diagnosis cases generally are very difficult, for they involve highly specialized experts who are judging what was reasonable based on “20-20 hindsight.” In mammogram cases, it boils down many times as to whether the tumor was palpable at the time of the exam.

Take, for instance, Kennedy v. U.S., 750 F.Supp. 206 (W.D. La.1990). In that case, Air Force hospital personnel were found negligent in failing to timely diagnose plaintiff’s breast cancer. After a lump was discovered, the patient was referred to a private hospital, where a mammogram proved inconclusive. Four months later, when the lump grew larger, the plaintiff was told not to worry. Instead of ordering a biopsy at that time, a repeat mammogram was ordered, the results of which were negative, and she was told to return in six months. When she returned 14 months later, a biopsy revealed malignancy and a radical mastectomy was performed, but the cancer already had metastasized to her sternum and lung, which required chemotherapy and radiation therapy.

Statute-of-Limitations Issues

A number of mammogram cases deal with statute-of-limitations question. Courts have been grappling with the notion of when a patient knew or should have known of an injury and the negligence that allegedly occurred in the failure to detect the cancer or in the improper reading of a mammogram.

Often, the courts use the standard that a cause of action for medical malpractice accrues upon discovery of metastasis or recurrence. as in Wolf v. Bueser, 279 Ill.App. 3d 217, 664 N.E.2d 197 (1st Dist. 1996). Other courts, however, have been harsh and toll the statute “when the treatment rendered after and relating to the allegedly wrongful act or omission is completed,” as the court held in Kocsis v. W.L. Harrison, 543 N.W.2d 164, 169 (Nev. 1996).

As in all medical negligence cases, a physician or radiologist will be judged by the recognized standard of medical care in the same speciality under similar circumstances in the general area in which the medical personnel practices. Therefore, although a doctor does not ensure the correctness of a diagnosis, he or she has the responsibility to use ordinary skill and diligence and to apply the means and methods generally used by similar medical personnel of ordinary skill and learning in the practice of the profession. When a doctor departs from this standard, he or she may be held liable for negligence. Take, for instance, Flowers v. Southampton Hospital, 627 N.Y.S.2d 81 (2d Dept. 1995), where the court found that sufficient evidence existed for a jury to conclude that the doctor’s misreading of the mammogram resulted in plaintiff’s cancer progressing from a stage-one lesion, which would have required radiation therapy, to stage-two, which forced her to undergo a modified radical mastectomy. Similarly, in Borgren v. U.S., 716 F.Supp. 1378 (D. Kan. 1989), the court held that Army physicians were negligent in failing to diagnose plaintiff’s breast cancer, which was indicated in mammograms taken one and three years prior to the discovery of a lump.

Performing Additional Tests

Furthermore, ordering a mammogram may be a recognized part of the diagnostic process, and failure to use such a test may constitute a deviation from the requisite standard of skill and diligence. However, even in the face of testing such as mammograms, and given their rate of error, a radiologist or physician may be held to order additional testing such as a biopsy, as the Kennedy decision points out, if the medical circumstances dictate. Total reliance on mammograms may not be reasonable under certain factual scenarios.

Technology developments in the new millennium will surely have an impact on this area of law. For instance, researchers at the University of North Carolina at Chapel Hill School of Medicine announced, about a year ago, the results of their study that found that images of the female breast created digitally could lead to more accurate breast cancer screening and diagnoses than traditional X-ray films. With X-rays, the only way to improve an image’s display is to look at it with a hot light or magnifying glass or expose a patient to more radiation in getting more images with greater magnification or focal compress. Digital systems, on the other hand, directly processed by a computer and displayed in different ways, thus producing multiple versions of the same image. Radiologists can manipulate the resulting pictures by changing the brightness, contrast and other characteristics, similar to altering the picture quality on a television set.

Ultimately, digital mammography is expected to replace film screen mammography in the effort to detect and treat tumors earlier.

This is surely the sign of even more sophisticated technology to come in the new millennium, which will, it is hoped, improve the quality of health care in the United States.


*Reprinted with permission from the January 2000 edition of The Journal Newsletters. © 2000 ALM Properties, Inc. All rights reserved.  Further duplication without permission is prohibited.

Facebook Twitter Email