Mary Jo Lund1,2,3,4, Marina Mošunjac5,3, Kelly M. Davis6, Sheryl Gabram‐Mendola7,3,8,4, Monica Rizzo7,3, Harvey L. Bumpers3,9, Sherita Hearn3,4, Amelia Zelnak2,3,4, Toncred M. Styblo7,4, Ruth O’Regan2,3,8,4
1Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia
2Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, Georgia
3Georgia Cancer Center for Excellence at Grady, Atlanta, Georgia
4Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia
5Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia
6Department of Internal Medicine, Emory University School of Medicine, Atlanta, Georgia
7Department of Surgery, Emory University School of Medicine, Atlanta, Georgia
8S.G. and R.M.O. are Georgia Cancer Coalition Distinguished Scholars
9Morehouse University School of Medicine, Atlanta, Georgia.
Tóm tắt
AbstractBACKGROUND:African American (AA) women experience higher breast cancer mortality than white (W) women. These differences persist even among estrogen receptor (ER)‐positive breast cancers. The 21‐gene recurrence score (RS) predicts recurrence in patients with ER‐positive/lymph node‐negative breast cancer according to RS score—low risk (RS, 0‐18), intermediate risk (RS, 19‐31), and high risk (RS, >31). The high‐risk group is most likely to benefit from chemotherapy, to achieve minimal benefit from hormonal therapy, and to exhibit lower ER levels (intrinsically luminal B cancers). In the current study, the authors investigated racial differences in RS testing, scores, treatment, and outcome.METHODS:Tumor registry data from 3 Atlanta hospitals identified women who were diagnosed with breast cancers during 2005 through 2009. Medical record abstraction provided information on RS and other tumor/treatment factors. Statistical analyses used chi‐square/exact tests and logistic regression.RESULTS:Of 2186 patients, including 1192 AA women and 992 W women, 853 women had stage I or II, ER‐positive/lymph node‐negative disease and, thus, were eligible for RS testing (AA = 372 [31.2%]; W = 481 [48.5%]; P < .0001); and 272 women (31.8%) received testing (AA = 76 [20.4%]; W = 196 [40.7%]; P < .0001). Tumors were distributed into the following groups according to risk: low risk (n = 133), medium risk (n = 113), and high risk (n = 26). The mean RS did not differ by race, but risk groups did (low‐risk group: 46.1% vs 50% for AA women and W women, respectively; high‐risk group: 15.8% vs 7.1%, respectively; P = .043). In multivariate analyses, AA race (odds ratio, 3.6) was associated independently with high risk scores.CONCLUSIONS:AA women were half as likely as W women to receive 21‐gene RS testing but were 2‐fold more likely to be categorized as high risk. The current data suggested that testing guidelines are not applied equivalently, testing bias may attenuate racial differences in RS, and disparate outcomes may be explained in part by differences in RS, although compliance and pharmacogenomics also may play a role. Cancer 2012;. © 2011 American Cancer Society.
