Women eligible for breast conservation surgery increasingly choose to undergo mastectomy

Issue: December 25, 2014

The percentage of women with early-stage breast cancer who are eligible for breast conservation surgery but still opt to undergo mastectomy has increased significantly since 1998, according to study results.

Breast reconstruction and bilateral mastectomy also have become more common in this population, results showed.

“This study looked at how we are currently treating early-stage breast cancer in the United States, … prompted by [an observation] in our own cancer center that more and more women seem to be undergoing more extensive operations than are necessary to treat their cancers,” study author Kristy L. Kummerow, MD, of the division of surgical oncology and endocrine surgery at Vanderbilt University Medical Center, told HemOnc Today. “Prior to the 1980s, the standard of care for any breast cancer … involved removal of the entire breast, as well as underlying and overlying tissues and multiple levels of lymph nodes drained by that area. Informative clinical trials in the 1980s demonstrated that these extensive procedures were unnecessary, and that equivalent survival could be achieved with a much more minimal operation. … This technique is now known as breast conservation surgery, or lumpectomy with radiation.”

Breast conservation surgery is now a quality metric, as accredited US breast centers are expected to perform the procedure in a majority of their patients with breast cancer, Kummerow said.

“However, what our research team observed at our institution didn’t fit — over time it appears more aggressive surgical approaches are being used for more women,” Kummerow said. “This has been found in other institutions as well, and is supported by smaller national studies.”

Kummerow and colleagues used the National Cancer Data Base to identify more than 1.2 million women treated for early-stage breast cancer between 1998 and 2011.

Overall, 35.5% of the population underwent mastectomy and 64.5% underwent breast conservation surgery. Patients who underwent mastectomy were younger (mean age, 59.6 vs. 61.6) and were more likely to be non-Hispanic white.

The percentage of women eligible for breast conservation therapy who instead opted to undergo mastectomy increased from 34.3% in 1998 to 37.8% in 2011 (P˂.001).

These trends were amplified in the last 8 years of the study period, results showed. Women eligible for breast conservation surgery were 34% more likely to undergo mastectomy in 2011 than they were in 2003 (OR=1.34; 95% CI, 1.31-1.38). Women with node-negative disease (OR=1.38; 95% CI, 1.34-1.41) and in situ disease (OR=2.05; 95% CI, 1.95-2.15) were significantly more likely to undergo mastectomy in 2011 than in 2003.

“Considering the variation in standards internationally, as well as the upward trend in our country, we can anticipate this issue is not going away,” Kummerow said. “The fact that trends in mastectomy for early breast cancer are steepest in women with pre-cancerous lesions compared to true invasive cancers suggests an increasing influence of factors unrelated to disease burden in performance of mastectomy, particularly in younger women. Moving forward, it is essential that our quality metrics are aligned with appropriate indications for mastectomy and bilateral mastectomy for early, one-sided tumors so that we send the right message to patients and so that providers are incentivized to provide appropriate care.”

Of the women who underwent mastectomy, 19.5% underwent bilateral mastectomy. Results showed the rate of women with unilateral disease who underwent bilateral mastectomy increased from 1.9% in 1998 to 11.2% in 2011 (P˂.001).

The rate for breast reconstruction also increased from 11.6% in 1998 to 36.4% in 2011 (P˂.001).

“We hope our data will increase awareness of current trends and prompt efforts to better understand what is driving decisions for mastectomy in early breast cancer,” Kummerow said. “At the end of the day, the operation that a women undergoes for early breast cancer should be determined by that individual woman and her provider; that said, the onus is on us as health care providers to take the time to make sure patients are truly informed of the risks and benefits of available treatment options and able to make decisions that incorporate good information with an understanding of outcomes that matter most to them.”

These trends suggest that guidelines for breast cancer management may need to be revisited, Bonnie Sun, MD, and Michael E. Zenilman, MD, both of the department of surgery at Johns Hopkins Medicine, wrote in an invited commentary.

“Existing guidelines are in place to ensure that patients are offered the appropriate options,” Sun and Zenilman wrote. “The article by Kummerow [and colleagues] should at least serve as a wake-up call that as we fulfill that responsibility, and use every modality of care to give patients the best quality of life and survival advantage, the guidelines may need to change again.”

Kristy L. Kummerow, MD, can be reached at Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, Tenn., 37232; email: kristy.l.kummerow@vanderbilt.edu.

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Disclosure: Zenilman reports a consultant role with Champions in Oncology. The researchers and Sun report no relevant financial disclosures.