New research from the The University of Texas MD Anderson Cancer Center found that African American women diagnosed with early stage invasive breast cancer were 12 percent less likely than Caucasian women with the same diagnosis to receive axillary sentinel lymph node (SLN) biopsy, a minimally invasive technique, which has become the standard surgical procedure.
Further findings of this study show that African American women who are subject to the older, more invasive procedure, axillary lymph node (ALN) dissection, show higher rates of lymphedema. These conclusions, previously presented at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium, updated and published in JAMA Surgery, were presented by Dalliah Black, assistant professor in MD Anderson’s Department of Surgical Oncology.
A minimally invasive procedure, SNL biopsy, for which about 75 percent of newly diagnosed breast cancer patients are eligible, has been the preferred practice for the staging of breast cancer since 2002 and became the standard of care in 2007, when it was endorsed by the National Comprehensive Cancer Network, together with other national organizations. A number of complications, including lymphedema, are associated with ALN dissection, the previously used technique.
“With this research, we wanted to determine if new surgical innovations were being incorporated equally amongst different patient populations,” says Black, who is the study’s first author. “This study looks at trends over time, comparing appropriate patients who all would have been candidates for the SLN biopsy to see how the new procedure was implemented in African Americans and Caucasians.”
This retrospective population-based study by the MD Anderson team was based on Medicare claims data between 2002 and 2007 from the Surveillance, Epidemiology and End Results (SEER) database in order to examine the surgical history of 31,274 women aged 66 and older, diagnosed with early-stage, invasive breast cancer. 1,767 (5 percent) of those women were African American, 27,856 (89 percent) were Caucasian and 1,651 (5.3 percent) were other, or of unknown race.
It has been found that 62 percent of African American patients received SLN biopsy, a number that compares with 74 percent of the Caucasian patients. Even though the SLN biopsy rate increased in both groups between 2002 and 2007, a fixed disparity persisted through the five years that the study analyzed.
Lymphedema, the most common side effect of ALN dissection, had an incidence of 12.2 percent in those who received this procedure, compared to 6.8 percent in those who received SLN biopsy. African Americans suffered a higher rate of the complication since 18 percent had lymphedema after axillary node dissection. However, patients who had the SLN biopsy ran a similar risk of lymphedema, regardless of race.
“The risk of lymphedema was primarily driven by differences in treatment: ALN dissection resulted in about twice the risk. When we looked at outcomes stratified by treatment, Caucasians and African Americans had similar risks of lymphedema if they had a SLN,” says Benjamin Smith, M.D., associate professor in MD Anderson’s Department of Radiation Oncology and senior author of the study. “This ties the treatment disparity to a disparity in outcome.”
Black and her team were thoroughly surprised at the findings.
“We were surprised to learn that the disparity persisted through 2007 and that there was an adverse patient outcome, lymphedema, associated with the findings. However, when we controlled for tumor characteristics and types of breast surgery, there was still a significant difference,” says Black.
“SLN is a safe and integral part of the surgical management of early invasive breast cancer. Improving patient education and creating ways to ensure all healthcare providers know practice guidelines and are able to implement them will help with this disparity. Appropriate patients with early stage breast cancer should not opt for less than this standard in care if properly educated,” Black continued.
Black and Smith led an MD Anderson team that included Thomas A. Buchholz, M.D., Executive Vice-President, Physician-in-Chief and Head of the Division of Radiation Oncology; Henry Kuerer, M.D., Ph.D., Professor, Department of Surgical Oncology and Jing Jiang, Department of Biostatistics, among others.
Reference: Dalliah M. Black, Jing Jiang, Henry M. Kuerer, Thomas A. Buchholz, Benjamin D. Smith. Racial Disparities in Adoption of Axillary Sentinel Lymph Node Biopsy and Lymphedema Risk in Women With Breast Cancer. JAMA Surgery, 2014.
Reprinted with Permission by BioNews Texas