Malignant Phyllodes Tumors of the Breast: Association Between Race, Clinical Features, and Outcomes

Background: We sought to investigate associations between race, clinical characteristics, and outcomes among patients with malignant phyllodes of the breast. Methods: Malignant phyllodes cases were identified using Surveillance Epidemiology and End Results database. We used chi-square tests to compare characteristics between racial groups and multinomial logistic regression to calculate relative risk ratios (RRR) and 95% confidence intervals (CI) comparing the likelihood of having particular characteristics by race. Survival analyses included Cox regression and Kaplan-Meier functions. Results: Among 1202 patients included, mean age was 51.7 y and 55.2% were white. Compared to whites, blacks were younger (mean age 45.7 versus 55.1 y; P < 0.001), and more likely to have tumors 51-100 mm (RRR = 1.91; 95% CI: 1.20-3.05) and tumors > 100 mm (RRR = 2.52; 95% CI: 1.56-4.05) than tumors < 50 mm in size. Compared to whites, Hispanics were younger (mean age 46.7 versus 55.1 y; P < 0.001), and more likely to have tumors 51100 mm (RRR = 1.46; 95% CI: 1.01-2.11) than tumors <= 50 mm in size. Asians were more likely to have tumors 51-100 mm (RRR = 1.52; 95% CI: 1.01-2.30) and tumors > 100 mm (RRR = 1.61; 95% CI: 1.03-2.52) than tumors <= 50 mm in size, and more likely to have tumors that extended beyond the breast tissue (RRR = 1.87; 95% CI: 1.05-3.31), compared to whites. Survival was similar for blacks (HR = 1.48; 95% CI: 0.80-2.76), Hispanics (HR = 1.02; 95% CI: 0.54-1.93), and Asians (HR = 1.13; 95% CI: 0.63-2.01) compared to whites. Conclusions: Further research into factors contributing to extensive disease at presentation among minorities is warranted. (C) 2019 Elsevier Inc. All rights reserved.