Abstract LB-393: Characterization of triple-negative breast cancer patients among Hispanics in Puerto Rico

Abstract

Abstract Introduction: Hormone receptor status had been correlated with prognosis in breast cancer patients. Breast cancer patients with no expression of estrogen receptor (ER), progesterone receptor (PR) and her-2 neu (her-2) have been grouped in the Triple Negative Breast Cancer (TNBC) category. At present, these patients have very limited adjuvant therapy alternatives. TNBC has been correlated with poor prognosis among African-American and Hispanic populations. However, there is very few data regarding the prevalence and characterization of TNBC among Hispanics groups (e.g. Puerto Ricans, Cubans, etc.). The objective of this study is to characterize the TNBC population among the Puerto Rican population and to assess whether expression of ER change the characteristics of the disease in this group. We hypothesize that expression of ER+ in her-2 negative breast cancer tumors will change the initial presentation of the disease. Methods: This cross-sectional study analyzed data from female patients with breast cancer diagnosed between 2000 and 2005, at the I. Gonzalez Martinez Hospital and the Auxilio Mutuo Hospital (n=1,082) in San Juan, Puerto Rico. Information on Her-2 status and other clinical characteristics was retrieved from the hospital's cancer registries and from medical record review. This study was approved by the Institutional Review Boards of the participating hospitals. Logistic regression models were used to evaluate the associations between relevant clinical characteristics and TNBC. We also evaluated whether there were any interaction between age, tumor size and receptor status. Results: The prevalence of TNBC in our study was 16.3% and 58.7% for the Her-2-ER+s phenotype. Patients in the TNBC group have younger age (<50 yr.) at diagnosis (24.3% vs 75.7%), bigger tumor size (>2cm) (70.3% vs 45.6%), invasive ductal histology (87.3% vs 68.7%), and higher tumor grades (III-IV) (49.7% vs 13.2%) compared to Her-2-ERs+. Using multinomial models, we found that, compared to TNBC, women with Her-2-ER+PR- and those with Her-2-ER+PR+ were 1.99 (CI95%= 1.15,3.44) and 1.66 (CI95%= 1.11, 2.46) times more likely to have > 50 years at diagnosis as compared to those with <50 years. This relationship is not seen in women with Her-2-ER-PR+ tumors. Furthermore, compared to TNBC, women with Her-2-ER+PR-are 0.4 (IC95%=0.24-0.67) times more likely to have tumors > 2cm. There was no interaction between receptor status, age and tumor size (p=0.582). Conclusions: TNBC in Hispanics from Puerto Rican origin showed the same prevalence of Hispanic women in California. Furthermore, disease characteristics (early age at diagnosis, tumor size, and histology and tumor grade) were also similar, suggesting that race has a significant effect in the presentation of TNBC in Hispanic women. In addition, the expression of ER, but not PR in Her-2 negative patients dramatically changes the initial presentation of the disease. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-393.