San Antonio, TX—Black women with clinically node-negative invasive breast cancer were less likely than white women to undergo sentinel lymph node biopsy (SLNB) for axillary staging and also were more likely to develop lymphedema, according to a study presented at the CTRC-AACR San Antonio Breast Cancer Symposium.
This study adds to the growing body of evidence documenting racial disparities in healthcare access.
“SLNB became the preferred technique for axillary staging in 2007 according to NCCN [National Comprehensive Cancer Network] guidelines. We looked at trends over time to determine if new recommendations were being incorporated across different patient populations. Our findings exemplify the need for continued improvement in disseminating national practice guidelines for breast cancer to patients and surgeons and other breast cancer providers in the United States,” said Dalliah M. Black, MD, FACS, Assistant Professor, Department of Surgical Oncology, Division of Surgery at M.D. Anderson Cancer Center, Houston.
The retrospective, population-based study utilized Medicare claims data between 2002 and 2007 from the SEER (Surveillance, Epidemiology and End Results) database to look at the surgical history of 31,274 women (age, ≥66 years) with node-negative breast cancer and a documented axillary surgical procedure. Of these, 1767 (5.7%) were black; 27,856 (89%) were white; and 1651 (5.3%) were of other or unknown race.
Overall, 62% of the black women and 74% of the white women underwent SLNB, representing a 12% disparity in receiving the recommended standard of care. In addition, 38% black women and 26% white women underwent axillary lymph node dissection (ALND). For the other or unknown races, SLNB was used in 65% and ALND in 35% of the patients. For blacks and whites in the study, the use of SLNB increased over time, which could reflect a learning curve, but the racial disparity persisted, Dr Black noted.
A multivariate analysis found that blacks were 33% less likely to receive SLNB; older patients, those with more comorbidities, and Medicaid recipients were also less likely to have SLNB.
The 5-year cumulative incidence of lymphedema was 18% in black women who underwent ALND compared with 12% in white women who underwent ALND; however, among women who received SLNB, the rates of lymphedema were 8.8% in black women and 6.8% in white women.
“The risk of lymphedema was primarily driven by differences in treatment. If blacks had SLNB, the rate of lymphedema was similar to white women who had SLNB. But black women who had ALND had twice the rate of lymphedema than patients who had SLNB,” Dr Black emphasized.
Overall, the investigators were surprised by these findings. “We were surprised to learn that this disparity persisted through 2007, and that there was an adverse patient outcome—lymphedema—associated with these findings. When we controlled for tumor characteristics and type of breast surgery, there was still a significant difference between whites and blacks,” she pointed out.
Dr Black said that the study emphasizes the need for focused education for minority populations and for their oncology treatment teams.
“We will be interested in looking at more contemporary data to determine whether the racial disparity persists after 2007,” Dr Black said.