Mastectomy Rates Have Risen Recently, as Has Breast MRI

Zosia Chustecka

May 21, 2008

May 21, 2008 — More women with early breast cancer are now opting for mastectomies than they were a few years ago and, at the same, the use of breast magnetic resonance imaging (MRI) has increased. Mayo Clinic researchers reporting the 2 trends speculate that they are related.

These findings were released during a presscast last week, ahead of formal presentation, scheduled for May 31, at the American Society of Clinical Oncology (ASCO) 2008 Annual Meeting.

The researchers, headed by Rajini Katipamula, MD, senior clinical fellow in hematology/oncology at the Mayo Clinic, in Rochester, Minnesota, analyzed data on 5464 women who had surgery for early-stage breast cancer at the Mayo Clinic between 1997 and 2006. They report that the rates of mastectomies fell from 45% in 1997 to 30% in 2003, but then rose to 43% in 2006.

Coauthor Matthew Goetz, MD, assistant professor of oncology at the Mayo Clinic, who presented the findings, commented that the fall in mastectomy rates in the late 1990s has been attributed to a report from the National Institutes of Health Consensus Panel, which said that lumpectomy with radiation was as effective as mastectomy for breast cancer in stages 1 and 2.

But what has prompted the recent rise in mastectomy rates? During the period when the increase was seen, the Mayo Clinic also increased its use of preoperative MRI. The percentage of women who underwent breast MRI scans doubled, from 11% in 2003 to 22% in 2006.

More than half the women (52%) who underwent an MRI scan went on to have a mastectomy, whereas 38% of women who did not have an MRI had a mastectomy. The difference is statistically significant (P < .0001). MRI has a better detection rate for breast cancer than other imaging modalities, so it is possible that the scans were detecting more breast cancer; however, there is also a high false-positive rate and MRI shows abnormalities that might not be cancer but might still require monitoring. Perhaps women in this situation opt for a mastectomy to spare themselves continued anxiety and periodic biopsies, the researchers speculated.

"This study demonstrates that a significant number of women with early-stage breast cancer are undergoing mastectomy, and it appears to be partially related to the introduction of preoperative MRI," Dr. Katipamula said in a statement.

Other Factors May Also Play a Role

There are other possibilities that need to be considered, Dr. Goetz commented during the presscast. In addition to the increasing use of preoperative breast MRI, recent years have seen several innovations, including improved techniques for breast reconstruction and the introduction of genetic testing. These factors could also be playing a role in influencing a woman's choice of whether or not to opt for a mastectomy.

Dr. Goetz noted that even among the women who did not have a preoperative MRI, the rate of mastectomies increased from 28% in 2003 to 41% in 2006.

Prospective studies are needed to determine which factors are most likely to indicate a change in surgical management, and whether these changes ultimately improve clinical outcomes and overall survival, Dr. Katipamula pointed out.

Julie Gralow, MD, a breast cancer specialist from Washington University, in Seattle, and moderator of the presscast, commented that there have been other reports across the United States of mastectomy rates increasing, and even reports of an increase in bilateral mastectomies in women who have unilateral breast cancer. "We really don't have a lot of data on why these rates are increasing, and this study has looked at 1 possible factor — the increasing use of breast MRI," she said.

Previous studies have shown that, in women with early breast cancer, an MRI performed at the time of diagnosis finds additional disease (not seen on mammography) in the same breast in 16% of cases, and finds disease in the other breast in about 3% to 4% of cases. It could be that there is a bias in the women who are referred for MRI, she continued; they might be women whose breasts are difficult to read on mammograms, or women who have more progressive disease. "So, it may be that this more aggressive surgery based on MRI is appropriate," she said.

"But it would be a real shame if women are choosing mastectomy because of MRI findings that are benign and turn out not to be cancer; they [would be] having more aggressive surgery than they need," she said.

Some women choose to maximize their risk reduction.

Some of it could be down to patients' choices, Dr. Gralow commented. Some patients choose a mastectomy over a lumpectomy to avoid radiation therapy, which is a requirement for breast-conservation surgery but is generally not needed when the breast is removed. There are also some data to suggest that leaving some breast tissue behind increases the rate of recurrence, either of the same cancer or new disease. One study showed a recurrence rate of 10% after lumpectomy, compared with 2% after a mastectomy, she noted. "Some women choose to maximize their risk reduction," she said.


Increasing Hospital Stay

Although mastectomy rates are rising, women are spending less and less time in the hospital after surgery. Some insurance companies won't cover the costs of hospital stays for more than 24 hours after a mastectomy, and 65% of the 125,000 patients undergoing mastectomies each year in the United States are sent home within 24 hours. A congressional panel that met today announced that it had bipartisan support for a bill that would require health insurers to pay for a minimum 48-hour hospital stay after the procedure to combat what critics have dubbed "drive-through" mastectomies.

Currently, about 20 states have minimum-insurance requirements for women undergoing mastectomies or lumpectomies to treat breast cancer, but advocates feel that this issue needs to be addressed on a national level. Advocates of the bill say federal legislation is needed to equalize coverage across the nation. In an open letter to Congress, Marisa Weiss, MD, a leading breast oncologist and founder and president of, wrote: "As someone who has treated thousands of women, I know that the care of these women at this most vulnerable and high-risk time must be individualized. There is no 'one size fits all' solution. To suggest otherwise demeans the challenge these women face in their fight against breast cancer. When insurers set themselves up as the 'hospital police,' short-cutting the in-hospital recovery process solely for economic reasons—and in disregard for best medical practice—legislation must be enacted to protect American lives."

The bill, HR 758, currently has bipartisan support and 219 cosponsors in the House of Representatives; a Senate companion bill currently has 19 cosponsors.

The researchers have disclosed no relevant financial relationships.

American Society of Clinical Oncology 2008 Annual Meeting: Abstract 509. Preview presscast, May 15, 2008.


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