How Good Can Mammograms Be? Suits Seek to Set a Standard
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By JANE E. BRODY
ecently, a jury in Hawaii awarded $1.32 million to a 57-year-old woman who said her breast cancer diagnosis had been delayed for 17 months because a radiologist had not found it on a mammogram. In New York, a 37-year-old woman won a $2.5 million malpractice suit against a radiologist who she said had failed to find her breast cancer on a mammogram done seven months earlier. In Florida, a jury awarded $3.35 million to a 56-year-old woman who claimed that her breast cancer diagnosis was delayed for six months because her cancer had been missed on a mammogram.
These are just some of a growing number of lawsuits asserting that a diagnosis of breast cancer was missed because a radiologist failed to find it on a mammogram.
Yet experts in the field say such lawsuits mainly stem from serious misconceptions about the ability of mammograms to detect cancers and from an assumption that the radiologists who read mammograms should be able to see things that may be discernible only in hindsight.
In the current American Journal of Roentgenology, Dr. Leonard Berlin, chairman of radiology at Rush-Presbyterian-St. Luke's Medical Center in Chicago, wrote 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." Radiologists who read mammograms are the main targets of these lawsuits, which often result in multimillion-dollar jury awards, even when no medical error has been committed by the doctors involved.
Robert A. Clifford, a plaintiff's lawyer in Chicago and vice chairman of the section on litigation of the American Bar Association, said: "Radiologists do miss these things. I've seen top-drawer radiologists miss it. I believe it's a volume issue where the doctor has too much business on his plate. He's rushed, harried and doesn't give it the time and attention it needs."
Dr. Berlin said in an interview: "Some lawsuits could have been due to errors made by radiologists. I'm not passing judgment as to the legitimacy of the allegations."
But Dr. Berlin believes that well-meaning efforts to encourage women to get regular mammograms have led to a highly inflated view of the accuracy of the technique. For example, in promoting mammography in the 1980's, the American Cancer Society stated, "Now, breast cancer has virtually nowhere to hide," even though 10 percent of known breast cancers in older women and up to 25 percent of cancers in young women cannot be seen on a mammogram.
Dr. Marc Homer, a professor of radiology at the Tufts University School of Medicine, said in an interview, "Mammography is the best tool we have for finding small, potentially curable breast cancers, but it's not 100 percent perfect." A cancer can be seen on a mammogram only if it looks different from the surrounding normal breast tissue, he explained, and some cancers are indistinguishable from normal tissue.
"Breast cancers like invasive lobular carcinomas can masquerade as normal, even if you can feel them," Dr. Homer said. In younger women, he added, the density of the breast tissue makes it difficult to recognize subtle early signs of cancer on a mammogram, even when more than one radiologist looks at the films.
"The public perception is that the mammogram is a test that is 100 percent accurate," Dr. Homer said. "A woman thinks, 'If I have cancer, it must be on the mammogram, and if the mammogram was read as normal, my cancer must have been missed.' " He added that he had seen advertisements by malpractice lawyers seeking clients whose cancers were initially undetected by mammography.
Dr. Daniel Kopans, a radiologist and mammography expert at the Massachusetts General Hospital in Boston, said in an interview: "I think we've elevated the expectations of women above reality. The legal system is holding us to a standard that's impossible to meet." He said there was no radiologist, no matter how competent and experienced, who "has not failed to see a significant abnormality on a mammogram," and added: "It's like looking for your keys in the morning and not being able to see them when they are right in front of you. Finding cancers on a mammogram can be much more difficult than finding the Ninas in a Hirschfeld drawing. No one tells us how many, if any, are in the picture. And they may not all be Ninas; some may be Janes or Dans."
The rapid rise in lawsuits involving mammography represents the flip side of arguments that have long raged over this technique. Many critics claim that its widespread use and doctors' fear of litigation has resulted in large numbers of unnecessary biopsies and operations for cancers that are unlikely ever to threaten a woman's life.
And while studies have indicated death rates from breast cancer are reduced by 30 percent when women over 50 have annual mammographic screening, the benefits to younger women are less clear because it is harder to see cancers in dense breast tissue.
Mammography can often find tiny cancers before they can be felt by a woman or her doctor and when they are presumed to be most curable. But the diagnosis and treatment of a tiny cancer is not a guarantee of cure. As Dr. Homer explained, "Some breast cancers are very aggressive even at a small size" and may have spread beyond the breast even before they can be felt. Others are slow-growing "and may only be recognizable on a mammogram when they grow larger," he said.
When used annually as a screening tool, mammography is most valuable when it finds hidden tumors before they have spread beyond the breast and while they are still potentially curable. But tumors that grow rapidly may become apparent as a discernible lump months after a routine mammogram has found no trace of it.
And when a woman or her doctor can feel a lump, "a negative mammogram is essentially meaningless," Dr. Kopans said, adding: "It does not tell someone she does not have breast cancer. Once something can be felt, it must be checked out further," for example, by ultrasound or biopsy. In some cases, a lump that an expert considers unlikely to be cancer may be watched for a few months to see if it will go away on its own. "But it cannot be ignored just because the mammogram is negative," Dr. Kopans said.
Efforts to improve the accuracy of mammograms have taken several paths. One is to have two experienced radiologists look at them independently, but not under the pressure of a woman who is waiting in the office for the results, Dr. Kopans said. Unrushed double readings can increase the accuracy of mammography by about 7 percent, his studies have shown. Another approach is the use of a computer-assisted second reading, a technique that has not yet been proved helpful but that has the potential to result in more accurate readings.
The American Cancer Society has also been urging women to seek out high-quality mammography. In its newest brochure and advertisements, the society tells women to ask questions about the office or center where they are getting their mammograms. They should seek out a place that specializes in mammography or does many mammograms each day; those that meet high professional standards of safety and quality should display a Food and Drug Administration certificate.
And if a woman changes medical sites, she is advised to bring copies of her previous mammograms so they can be compared to the current ones, which can make it easier for a radiologist to detect a change that may be medically significant.
nytimes.com |
