Women with breast cancer who undergo partial-breast removal are just as likely to survive for at least 20 years as are women who have their entire breast removed, scientists in Italy and the United States report.
While many physicians have already accepted partial-breast removal as a safe approach for small tumors confined to the breast and nearby lymph nodes, so-called early-stage breast cancers, some still recommend mastectomy, removal of the entire breast. The new findings, from the longest follow-up studies of such patients to date, could put to rest any lingering doubts that doctors and patients have regarding breast-conserving surgery. The studies appear in the Oct. 17 New England Journal of Medicine.
Between 1973 and 1980, surgeon Umberto Veronesi of the European Institute of Oncology in Milan and his colleagues randomly assigned 352 women with early-stage breast cancer to undergo surgery that preserved most of the breast and 349 others to have a full mastectomy that also removed some chest muscle. All women in both groups received radiation treatments afterward.
Twenty years after their surgery, roughly two-fifths of patients in each group had died, the researchers report.
In the same journal issue, surgeon Bernard Fisher of the University of Pittsburgh and his colleagues report similar results from a study of women diagnosed with early-stage breast cancer between 1976 and 1984. The researchers randomly assigned 589 women to get a mastectomy, 634 to undergo a type of partial-breast removal known as lumpectomy, and 628 to have a lumpectomy plus radiation treatment. In lumpectomy, a surgeon removes the tumor and a minimal amount of surrounding breast tissue.
After an average of 20 years, slightly more than half of the women in all three groups had died, regardless of treatment. Those receiving radiation treatment after their lumpectomy had fewer recurrences of breast cancer, compared with women who didn’t get radiation.
“These [research] papers are of monumental importance,” says Melvin J. Silverstein, a surgeon at the University of Southern California Keck School of Medicine in Los Angeles. While doctors generally present breast-conserving surgery as an option, he says, some doctors–mainly those in rural areas–don’t. As a result, many women undergo mastectomies for cancers that could be treated just as well with a lumpectomy and radiation, he says.
The two studies aren’t identical. The European surgeons removed more tissue. Also, the tumors of U.S. patients tended to be larger and their cancer had more frequently spread to lymph nodes. These traits could explain the slightly greater survival of the European women, Fisher says. It might also account for another difference: The cancer-recurrence rate in women getting partial breast removal plus radiation was 9 percent in the European trial and 14 percent in the U.S. study.
These rates, he says, reflect the standard of care 2 decades ago. Since then, the recurrence rate in lumpectomy patients has declined.
Mastectomy remains a worthwhile option for women who are genetically predisposed to breast cancer or those whose cancer has spread or recurred, says Jeffrey S. Abrams, a medical oncologist at the National Cancer Institute in Rockville, Md.
But for most women with early-stage breast cancers, “it’s time to declare the case against breast-conserving therapy closed,” says Monica Morrow of Northwestern University’s Feinberg School of Medicine in Chicago in the same journal issue.
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