New Method May Offer Alternative to Breast Biopsies : Health: Radioactive tracer correctly identifies 90% of tumors in study. Two other reports support value of mammograms for women in their 40s.
A UCLA researcher has developed a new technique for detecting breast cancer that could eliminate many, if not most, of the unnecessary biopsies now performed when mammography shows suspicious lumps.
Dr. Iraj Khalkhali discovered that a radioactive tracer used for diagnosing heart disease migrates to the site of a breast tumor, where a suspicious accumulation can then be detected with a scintillation camera. The process is painless and harmless and costs a fraction of the price of a biopsy.
Tests on 147 women at Harbor-UCLA Medical Center showed that the technique correctly identified 90% of tumors, Khalkhali said Monday at a meeting of the Radiological Society of North America in Chicago.
Khalkhali is “a pioneer” in his development of the technique, said Dr. Stephen Larson of Memorial Sloan-Kettering Cancer Institute in New York City. “It sounds very good,” he said, “but it remains to be seen whether others will have a similar experience. . . . We probably will try it soon.”
In two separate studies presented at the same meeting, results strongly supported the value of mammography screenings in women between the ages of 40 and 49.
Guidelines from the National Cancer Institute--revised a year ago amid heavy debate--now recommend against screening in that age group on the grounds that it has not been proved effective.
But the American Cancer Society and at least 17 other groups have continued to recommend mammograms for women in their 40s, and the new studies buttress their position.
“Our study of more than 250,000 mammographic examinations predicts a survival advantage for women who are having regular mammograms either before or after age 50,” said Dr. Linda Warren Burhenne of the University of British Columbia in Vancouver, director of one study.
“The women we screened under the age of 50, however, had fewer invasive cancers and less involvement of lymph nodes in the armpits . . . and were eligible for conservative therapy.”
The second study, at Thomas Jefferson University Hospital in Philadelphia, found that women who had annual mammograms had the best chance of recovery and the most treatment options, regardless of age.
“Although our findings are consistent and significant across all age groups, they especially underscore the need for mammography in women under 50,” said Dr. Stephen A. Feig of Thomas Jefferson, co-director of the study.
But Dr. Barry Kramer of the National Cancer Institute noted that neither study was able to report that early detection of the breast tumors actually prolonged the women’s lives. Both studies, he said, only observed the progress of the patients without having a control group, as would be the case in a randomized clinical trial.
“Observational data cannot go beyond suggestion,” he said. “It is not proof.”
The need to screen women in their 40s has been a subject of controversy for several years, but the dispute reached a peak in December when the institute issued new guidelines indicating that physicians do not agree on the effectiveness of mammography for women in this age group--implicitly arguing against such screening.
An investigation of that decision by the House Committee on Government Operations, issued in October, concluded that the institute had stacked the deck against mammography in forming the panel that issued the guidelines. The House report concluded that, contrary to National Institutes of Health rules that require an impartial panel, all members of the committee opposed such screening.
One factor that has argued against the use of mammography in younger women is the large number of “false positives” obtained in mammography. “Only one out of every four or five suspicious lesions seen on a mammogram turns out to be a cancer,” Khalkhali said.
To check out suspected tumors, physicians now perform biopsies to remove tissue from the suspected tumor and determine if it is malignant. Biopsies can be painful and, occasionally, disfiguring. They are also relatively expensive, averaging $3,000 to $4,000 throughout the country and as much as $5,000 in Los Angeles.
The new test announced Monday, in contrast, costs about $600. “If we could eliminate 50% of unnecessary biopsies, we could save $150 million per year,” Khalkhali said.
Although the technique has been used on more than 600 women at Harbor-UCLA, follow-up results were available for only 147 women, who had 153 suspicious masses. The technique identified 90% of the tumors correctly. There were 11 false positives and only four false negatives, in which a tumor was missed.
Based on these results, Khalkhali has begun a study that will enroll 600 women at 60 medical centers throughout the country. Results from that study are expected in about six months, he said, and the technique could be widely available in two years.
The Vancouver mammography study involved all women in the province of British Columbia who had mammograms--about 40% of women over 40. About 34% of the 150,147 women studied were under age 50, and they accounted for 15% of the tumors detected, Burhenne said. Nearly 87% of the tumors found in these women were identified at an early, curable stage, before the cancer had spread to a lymph node.
She noted that British Columbia has the highest incidence of breast cancer in Canada, yet mortality from the disease is second-lowest and continues to decline. “Their cancers are being caught and treated early,” she said, and that is saving lives.
Feig reported similar results with 3,159 women who had breast biopsies at Thomas Jefferson Hospital. He argued that frequent mammograms are more important in younger than in older women because tumors in the younger women grow faster.
He agreed with the cancer institute’s Kramer that neither study provides proof that screening of young women saves lives, “but they do offer very strong evidence. They should convince any reasonable person that screening does work under age 50.”
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