Black Women Less Likely to Receive Improved Surgical Procedure for Breast Cancer

This abstract will be presented at a press conference hosted by Peter Ravdin, M.D., Ph.D., director of the Breast Health Clinic at the CTRC, on Wednesday, Dec. 5 at 7:30 a.m. CT in Room 217 A-C of the Henry B. Gonzales Convention Center. Reporters who cannot attend in person can call in using the following information:• U.S./Canada (toll free): 1 (800) 446-2782• International (toll call): 1 (847) 413-3235

Newswise — SAN ANTONIO — Black women with breast cancer were 12 percent less likely than white women with the disease to receive a more minimally invasive procedure — sentinel lymph node biopsy — for staging of breast cancer, according to data tracking the treatment of patients through 2007.

“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 here 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.

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The mission of the 2012 CTRC-AACR San Antonio Breast Cancer Symposium is to produce a unique and comprehensive scientific meeting that encompasses the full spectrum of breast cancer research, facilitating the rapid translation of new knowledge into better care for patients with breast cancer. The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio, the American Association for Cancer Research (AACR) and Baylor College of Medicine are joint sponsors of the San Antonio Breast Cancer Symposium. This collaboration utilizes the clinical strengths of the CTRC and Baylor and the AACR’s scientific prestige in basic, translational and clinical cancer research to expedite the delivery of the latest scientific advances to the clinic. For more information about the symposium, please visit www.sabcs.org.

Abstract:Publication Number: S2-3

Title: Disparities in the utilization of axillary sentinel lymph node biopsy among black and white patients with node-negative breast cancer from 2002-2007.

Dalliah M Black1, Jing Jiang2, Henry M Kuerer1, Thomas A Buchholz2 and Benjamin D Smith2. 1Surgical Oncology, MD Anderson Cancer Center, Houston, TX and 2Radiation Oncology, MD Anderson Cancer Center, Houston, TX.

Body: Background: Disparities exist in many aspects of standard breast cancer treatment in certain patient populations. In the mid-1990s, axillary sentinel lymph node biopsy (SLNB) was introduced as an alternative to axillary lymph node dissection (ALND) for staging clinically node-negative invasive breast cancer. During the early 2000s, the validity of SLNB was being determined and its technique was being disseminated throughout the surgical community. By the mid to late-2000s, SLNB had been shown to provide accurate axillary staging with lower complications and no difference in survival compared to ALND in node-negative patients. SLNB has now replaced ALND as the accepted method for staging early breast cancer. The purpose of this study is to examine differences in the utilization of SLNB in pathologic node-negative black breast cancer patients compared to white patients as SLNB became standard axillary staging and whether this difference impacted patient complications.

Methods: Using the population-based Surveillance, Epidemiology, and End Results (SEER)-Medicare data, cases of incident, non-metastatic, pathologic node-negative breast cancer in women age≥66 were identified. Patients were considered to have undergone SLNB if specified by SEER records or if a billing claim for axillary lymphatic mapping was identified. Unadjusted associations of SLNB with race were evaluated using the chi-square test. The Cochran-Armitage test evaluated trends over time. Multivariate logistic regression tested whether race was associated with the use of SLNB after adjustment for clinicopathologic factors. Five-year cumulative incidence of lymphedema assessed via ICD-9 diagnosis codes was measured using the Kaplan-Meier method. Adjusted proportional hazards regression evaluated associations of race and ALND with lymphedema risk.

Results: Of 31,274 women identified, 1,767 (5.7%) were Black, 27,856 (89%) were White and 1,651 (5.3%) were of other/unknown race. SLNB was performed in 74% of white patients compared to 62% of black patients (P<0.001). Although use of SLNB increased by year for both black and white patients (P<0.001), a fixed disparity in the use of SLNB persisted through 2007 (see graph). In adjusted analysis, black patients were 33% less likely than white patients to undergo SLNB (relative risk = 0.74, 95% CI 0.67-0.81; P<0.001). Five-year cumulative incidence of lymphedema was 11.4% in patients undergoing ALND vs. 6.3% in patients undergoing SLNB (adjusted HR 1.92, 95% CI 1.75-2.10; P<0.001). Overall, black race was also associated with a higher risk of lymphedema (adjusted HR 1.40; 95% CI 1.20-1.63; P<0.001). However, among patients undergoing SLNB, whites and blacks had similar risks of lymphedema (6.2% and 7.7%, respectively; P=0.08).

Conclusion: Even with the increased use of SLNB and its acceptance as standard axillary staging for node-negative breast cancer patients, disparities persist in its underutilization in appropriate black patients compared to white patients by as much as 26%. This racial disparity in SLNB use translated to a higher risk of lymphedema for black patients. Improving surgeon practices, the multidisciplinary team approach, and patient education are important in optimizing the beneficial impact of SLNB and reducing complications from unnecessary ALNDs in all patients with early stage breast cancer. Future research is needed to delineate mechanisms underlying this persistent disparity and to identify strategies to mitigate it.