Abstract P4-10-20: Breast cancer in Brazil: HER-2 testing and treatment patterns

Abstract

Abstract BACKGROUND Breast cancer is the most common cancer among Brazilian women. HER-2 targeted therapy improves overall survival in HER-2 overexpressing patients but immunohistochemistry testing for HER2 is not standardized in Brazil and is not available universally. In Brazil the health system includes a public and private sector. The aim of our study was to delineate the patterns of testing of HER-2 over time in Brazil in both of these settings and to determine if any disparities exist in testing and treatments received. METHODS Observational, retrospective study involving practice patterns of over 2000 cancer physicians in Brazil. We obtained de-identified data from a commercial database, which included 54,829 patients with breast cancer treated between 2012 and 2016. We analyzed the frequency of HER-2 testing, the percentage of positive results and the most common treatments used in the first line setting in both the private and public sector. The chi-squared test was used for proportions. RESULTS HER-2 testing was frequently performed in both the private and public sector (87% vs. 81%, p<0.0001. Between 2012 and 2016 most patients had HER-2 testing (88%, 73%, 79%, 90% and 88%, respectively) but coverage was not universal. The percentage of HER-2 positivity was 25%. The most common first line regimens used were docetaxel/trastuzumab, paclitaxel/trastuzumab and trastuzumab monotherapy. In the private sector trastuzumab/pertuzumab/docetaxel was the most commonly used regimen. In the public sector taxanes were frequently used as monotherapy without HER-2 targeted therapy. CONCLUSIONS To our knowledge this is the largest dataset assessing HER-2 testing and treatment patterns in Brazil. The frequency of testing has remained stable over the last 5 years, but is higher in the private sector and this finding was highly statistically significant. There are also differences in the regimens used in the private vs. public sector. Pertuzumab was approved in 2013 in the US and its use has increased in Brazil over the last two years. This trend however was only seen in the private sector. In the public sector there is still significant use of chemotherapy without HER-2 directed therapy despite HER-2 overexpression, which is possibly related to the restricted access of anti-HER2 therapy in the public health system for metastatic patients. Taxanes are used widely in both the public and private sector, which is possibly related to the availability of generics. HER 2 Testing in the Public Sector20122013201420152016Tested4,2853,7114,5924,6884,126%92%76%80%94%91%Non Tested36211441134322428%8%24%20%6%9%Total4,6474,8555,7265,0104,554 HER 2 Testing in the Public Sector20122013201420152016Tested5,3913,9964,9175,2084,945%85%71%78%87%85%Non Tested9491,6611,367761842%15%29%22%13%15%Total6,3405,6576,2845,9695,787 Citation Format: Palacio S, Torres A, Prado E, Lopes G. Breast cancer in Brazil: HER-2 testing and treatment patterns [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-10-20.