ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Wednesday, July 3, 1996 TAG: 9607030056
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
SOURCE: The Boston Globe
NOTE: below
THE STUDY'S findings now have doctors debating whether women under 50 should get mammograms yearly to protect breasts.
Adding a disturbing twist to understanding breast cancer, researchers have a new explanation for the ineffectiveness of mammograms in detecting many tumors in women under 50: Tumors in younger women grow much more rapidly.
The new study, published in the Journal of the American Medical Association, tracked 28,000 women who received mammograms over a seven-year period to see what kind of tumors they developed and when.
They found that mammograms, or breast X-rays, detected 75 percent of cancers in women in their 40s but 93 percent in women over 50. They also observed that the tumors in the under-50 women grew much faster than those in older women.
Until now, most physicians believed that the main reason mammograms missed more cancers in younger women was that the women's denser breast tissue hid small tumors.
But the new findings suggest the primary reason is that younger women's tumors ``can go from undetectably small to large between screening exams,'' said Dr. Karla Kerlikowske, lead author of the study and an assistant professor of medicine, epidemiology and biostatistics at the University of California, San Francisco.
Some specialists seized on these findings to support their contention that all women in their 40s should receive annual breast exams, rather than an exam every two years or none at all until they're 50. Most major groups, such as the American Cancer Society, recommend that women receive mammograms at least every other year starting at age 40.
``Many of us have argued for years that we should be screening women in their 40s every year, and this paper corroborates that,'' said Dr. Daniel Kopans, director of the breast imaging division at Massachusetts General Hospital. ``If you screen every two years, you'd be finding tumors about the time the doctor or woman was going to feel it anyway.''
Kopans also points to a new Swedish study of 150,000 women that found a 24 percent lower death rate among women who got mammograms beginning in their 40s. ``For years, randomized trials did not show a benefit from screening women in their 40s,'' Kopans said. ``But the Swedish study and other trials now show a statistically significant benefit.''
However, Kerlikowske says her findings do not support mammography screening for all women in their 40s. Breast cancer is much less common among women in that age group than older women, Kerlikowske notes, arguing that the benefit of detecting the occasional malignancy is outweighed for most women by the risk of going through unnecessary biopsies and surgeries when abnormal results are found through mammograms.
``Over half of all lesions found in younger women are not invasive cancers,'' said Kerlikowske, who is also associate director of the San Francisco VA Medical Center's Women Veterans Comprehensive Health Center. ``So if the mammogram picks something up, you are faced with what are you going do about it. By screening younger women, you are generating a lot of unnecessary false positive results and anxiety.''
As an example, Kerlikowski cited the case of a 36-year-old woman who is at very low risk of breast cancer, primarily because of her age and the fact that she has five children, no family history of breast cancer and is not overweight. But a recent mammogram found some calcifications in her breasts and she must now have them biopsied.
The woman is also considering having two lumpectomies to remove the lesions, even though the chance of her having cancer is 1 in 2,500, Kerlikowski said.
``The problem is once people find these lumps, they can't not act on them,'' she noted. ``Sometimes ignorance is bliss.''
But Kopans and other radiologists disagree. In an editorial accompanying the San Francisco study, Dr. Stephen A. Feig, of Thomas Jefferson University Hospital, said the new results indicate that women in their 40s should receive annual exams.
And while Kerlikowske is opposed to routine exams for women under 50, she notes that if younger women want a mammogram and are prepared to take the risk of unnecessary intervention, they should have one every year rather than every two years.
LENGTH: Medium: 81 linesby CNB