"These findings are an example of the need for continued improvements in disseminating national practice guidelines for breast cancer to surgeons and other breast cancer providers in all of our communities," said Dalliah Mashon Black, M.D., assistant professor of surgery in the department of surgical oncology at The University of Texas MD Anderson Cancer Center in Houston. Black presented the data at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium, held in San Antonio Dec. 4-8.

Axillary sentinel lymph node (SLN) biopsy became a recommended alternative to the more invasive procedure of axillary lymph node dissection (ALND) for staging clinically node-negative breast cancer in the mid-2000s. Although effective, ALND is associated with increased short-term and long-term complications, according to Black.

Using data from the Surveillance, Epidemiology and End Results (SEER)-Medicare database, Black and colleagues evaluated whether there was a difference in the utilization of SLN biopsy in black patients compared to white patients and whether this difference impacted the risk for lymphedema, which is a complication characterized by arm swelling that may occur after axillary surgery.

Data were from 31,274 women aged 66 or older, including 1,767 black women, 27,856 white women and 1,651 women of other or unknown race.

Sixty-two percent of black women underwent SLN biopsy compared with 74 percent of white women. The use of SLN biopsy increased each year for all patients, but disparities persisted through 2007.

"From 2002, when surgeons were still incorporating SLN biopsy into practice, until 2007, black women were less likely to have undergone an SLN biopsy than were white women," Black said. "The fact that this disparity continued over time shows that new and improved surgical therapies may not be effectively implemented in some patient populations."

Black women remained significantly less likely to receive SLN biopsy compared with white women despite adjustment for tumor size, patient sociodemographics and type of breast surgery. Furthermore, ALND was associated with twice the risk for lymphedema in black patients compared with patients treated with SLN biopsy.

Black and colleagues hope to update this study with data from the 2010 SEER-Medicare database to evaluate whether improvements have been made since 2007.

Black stressed that these data highlight the need for improving national implementation of changes in practice standards and for understanding how physician cancer teams incorporate recommendations in different patient populations.

"When we think of disparities, it doesn't only mean that patients might be undertreated, but they could be overtreated with unnecessary and more radical procedures, leading to a higher risk for complications, as shown in this study," she said.