부산대학교 도서관

Introduction: Breast cancer can be divided into four subtypes based on the expressions of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor-2 (HER2). Each subtype has different clinicopathological features and outcomes. Objective: To compare the clinicopathological features and survival of ER and/or PR positive HER2 negative (ER+PR+HER2−, ER+PR−HER2− or ER−PR+HER2−), ER and/or PR positive HER2 positive (ER+PR+HER2+, ER+PR−HER2+ or ER−PR+HER2+), ER negative PR negative HER2 positive (ER−PR−HER2+), and ER negative PR negative HER2 negative (ER−PR−HER2−) subtypes. Methods: 1957 patients with Stage 1-3 breast carcinoma diagnosed between Jan 2005 and Dec 2011 were categorized into the four subtypes. The clinicopathological features between the subtypes were compared using χ test. Kaplan-Meier analysis was performed to estimate 5-year overall survival. Multivariate Cox regression was used to determine the association between subtypes and mortality adjusted for age, ethnicity, stage, pathological features, and treatment. Results: ER−PR−HER2+ and ER−PR−HER2− subtypes were associated with younger age, larger tumors, and higher grade. There was no difference in the 5-year survival of the ER−PR−HER2+ and ER−PR−HER2− subtypes (75.1 and 74.4 %, respectively) and survival was poorer than in the ER and/or PR positive HER2 negative and ER and/or PR positive HER2 positive subtypes (87.1 and 83.1 %, respectively). Only 9.5 % of women with HER2 positive breast cancer had access to trastuzumab. Conclusion: In a low resource setting with limited access to trastuzumab, there is no difference in survival between the ER−PR−HER2+ and ER−PR−HER2− subtypes of breast cancer. [ABSTRACT FROM AUTHOR]