Racial differences in clinical outcomes from metastatic breast cancer: a pooled analysis of CALGB 9342 and 9840--Cancer and Leukemia Group B.

PURPOSE African American women are more likely to be diagnosed with metastatic breast cancer at the time of presentation than whites, and have shorter survival once diagnosed. This study examines racial differences in clinical outcomes in the setting of two large cooperative group randomized clinical trials. PATIENTS AND METHODS The study cohort consisted of 787 white (80%) and 195 African American (20%) patients with metastatic breast cancer enrolled in two successive Cancer and Leukemia Group B (CALGB) trials using taxanes in the metastatic setting. Differences in overall survival (OS), response incidence, and time to treatment failure (TTF) were examined by race. In addition, differences in the incidence of baseline and treatment-related toxicities were examined. RESULTS With 779 deaths (166 African Americans and 613 whites), median OS was 14.3 months for African Americans and 18.75 months for whites (hazard ratio [HR] = 1.37; 95% CI, 1.15 to 1.63). When adjusted for prognostic factors, African Americans had a 24% increase in the hazard of death compared with whites (HR = 1.24; 95% CI, 1.02 to 1.51). No significant differences in TTF or overall response to therapy were seen. No clinically significant toxicity differences were seen. CONCLUSION African Americans with metastatic breast cancer have an increased hazard of death compared with whites despite the receipt of similar per-protocol treatment, but experience no differences in TTF or overall response to therapy. We hypothesize that more direct and robust measures of comorbidities, and perhaps other factors such as receipt of subsequent therapy could help further explain the observed survival difference.

[1]  K. Berhane,et al.  Prevalence and Correlates of Anemia in a Large Cohort of HIV‐Infected Women: Women's Interagency HIV Study , 2001, Journal of acquired immune deficiency syndromes.

[2]  J. Dignam.  Differences in breast cancer prognosis among African‐American and Caucasian women , 2000, CA: a cancer journal for clinicians.

[3]  V. Chen,et al.  Racial disparity in the association of p53 gene alterations with breast cancer survival. , 1995, Cancer research.

[4]  E. Feuer,et al.  SEER Cancer Statistics Review, 1975-2003 , 2006 .

[5]  D. Nerenz,et al.  Comorbidity and survival disparities among black and white patients with breast cancer. , 2005, JAMA.

[6]  R. Millikan,et al.  Genetic polymorphisms in uridine diphospho-glucuronosyltransferase 1A1 and association with breast cancer among African Americans. , 2000, Cancer research.

[7]  V. Chen,et al.  Patterns of DNA ploidy and S-phase fraction associated with breast cancer survival in blacks and whites. , 1997, Clinical cancer research : an official journal of the American Association for Cancer Research.

[8]  C. Perou,et al.  Race, breast cancer subtypes, and survival in the Carolina Breast Cancer Study. , 2006, JAMA.

[9]  Carol West,et al.  Hematologic differences between African-Americans and whites: the roles of iron deficiency and alpha-thalassemia on hemoglobin levels and mean corpuscular volume. , 2005, Blood.

[10]  K. Malone,et al.  Differences in breast cancer stage, treatment, and survival by race and ethnicity. , 2003, Archives of internal medicine.

[11]  J. Griggs,et al.  Racial Disparity in the Dose and Dose Intensity of Breast Cancer Adjuvant Chemotherapy , 2003, Breast Cancer Research and Treatment.

[12]  San Antonio.  6th annual san antonio breast cancer symposium , 2005, Breast Cancer Research and Treatment.

[13]  R. Coates,et al.  Racial differences in the expression of cell cycle–regulatory proteins in breast carcinoma , 2004, Cancer.

[14]  D. Berry,et al.  Failure of higher-dose paclitaxel to improve outcome in patients with metastatic breast cancer: cancer and leukemia group B trial 9342. , 2004, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[15]  E. Feuer,et al.  SEER Cancer Statistics Review, 1975-2003, National Cancer Institute. Bethesda, MD, , 2006 .

[16]  S. Seliger,et al.  Racial variations in erythropoietic response to epoetin alfa in chronic kidney disease and the impact of smoking. , 2005, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association.

[17]  S. Joslyn.  Racial differences in survival from breast cancer. , 1995, JAMA.

[18]  A. Neugut,et al.  Ethnic neutropenia and treatment delay in African American women undergoing chemotherapy for early-stage breast cancer. , 2003, Journal of the National Cancer Institute.

[19]  N. Breen,et al.  The relationship of socio-economic status and access to minimum expected therapy among female breast cancer patients in the National Cancer Institute Black-White Cancer Survival Study. , 1999, Ethnicity & disease.

[20]  G. Colditz,et al.  African‐American ethnicity, socioeconomic status, and breast cancer survival , 2002, Cancer.

[21]  D. Collet.  Modelling Survival Data in Medical Research , 2004 .

[22]  D. Hosmer,et al.  Applied Logistic Regression , 1991 .

[23]  G. Kimmick,et al.  A comparison of treatment outcomes for black patients and white patients with metastatic breast cancer. The piedmont oncology association experience , 1991, Cancer.

[24]  Donald Berry,et al.  Molecular subtypes of breast cancer in relation to paclitaxel response and outcomes in women with metastatic disease: results from CALGB 9342 , 2006, Breast Cancer Research.

[25]  K. Malone,et al.  Differences in breast cancer hormone receptor status and histology by race and ethnicity among women 50 years of age and older. , 2002, Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology.

[26]  H. Hibshoosh,et al.  African‐American/White differences in breast carcinoma , 2005, Cancer.

[27]  D. Wickerham,et al.  Effects of obesity and race on prognosis in lymph node-negative, estrogen receptor-negative breast cancer , 2006, Breast Cancer Research and Treatment.

[28]  D. Schrag,et al.  Missed opportunities: racial disparities in adjuvant breast cancer treatment. , 2006, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[29]  G M Clark,et al.  Tumor biologic factors and breast cancer prognosis among white, Hispanic, and black women in the United States. , 1994, Journal of the National Cancer Institute.

[30]  J. Dignam.  Efficacy of systemic adjuvant therapy for breast cancer in African-American and Caucasian women. , 2001, Journal of the National Cancer Institute. Monographs.

[31]  L. Ries,et al.  Frequency distributions of breast cancer characteristics classified by estrogen receptor and progesterone receptor status for eight racial/ethnic groups , 2001, Cancer.

[32]  E. Taioli,et al.  A CYP1A1 restriction fragment length polymorphism is associated with breast cancer in African-American women. , 1995, Cancer research.

[33]  D. Berry,et al.  Race and survival from breast cancer: based on Cancer and Leukemia Group B trial 8541. , 1997, The cancer journal from Scientific American.

[34]  H. Freeman,et al.  Racial disparities in breast carcinoma survival rates , 2003, Cancer.

[35]  C K Redmond,et al.  Racial differences in survival from breast cancer. Results of the National Cancer Institute Black/White Cancer Survival Study. , 1994, JAMA.

[36]  A. Neugut,et al.  Racial disparities in treatment and survival among women with early-stage breast cancer. , 2005, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.