Abstract P1-08-29: Current status of clinical and pathological characteristics of breast cancer patients in Brazil: Results of the AMAZONA III study (GBECAM 0115)

Abstract BACKGROUND Breast cancer (BC) is the most common tumor in women in Brazil with about 60 thousand new cases estimated per year. In low and middle-income countries, patients with BC are diagnosed with more advanced stages as compared with high-income countries. In Brazil, disparities in access to new therapies are recognized; previous data suggests worse survival of BC patients treated in the public system. The aim of AMAZONA III study (GBECAM 0115) is to describe the current status of BC care in Brazil. Here we report patients data at baseline. METHODS The AMAZONA III is a prospective BC registry that included women 18 years or older with newly diagnosed stage I to IV BC from 22 sites in Brazil in the period of January 2016 to March 2018. All patients provided written informed consent; data was collected from interview and medical charts, comprising clinical-demographic variables, initial treatment and a planned follow-up for 5 years. BC subtypes were defined by hormone receptor (HR) expression, HER2 status and grade according to von Minckwitz G. et al 2012. Here we present a descriptive analysis of the patients' baseline characteristics. Continuous variables are shown as mean (standard-deviation) and categorical variables by its absolute and relative frequencies. The study is registered in clinicaltrials.gov NCT02663973. RESULTS A total of 2950 patients were included in the study. Median age at diagnosis was 53 years old (8.4% <= 35 years, 34.8% 36-50 years, 56.8% > 50 years), 58.6% were white, 34.4% had brown skin-color, 83% had children before BC diagnosis (median of 1 child/patient) and 63.1% had public health insurance. In terms of method of detection 34% were screen-detected whereas 66% were symptomatic, the last was even higher (70%) in patients in younger than 50 years. The distribution of BC stage at diagnosis was I (26.4%), II (41.6%), III (27%) and IV (5%). The most common histologies were ductal (80.9%) and lobular carcinoma (6.9%). The pathological characteristics were HR positive in 78.0%, HER-2 positive in 23.4% and grade 2 in 51%. BC subtypes were as follows: Luminal A 48%, Luminal B 12%, Luminal HER2 positive 17%, Non-luminal HER2 positive 7.3% and Triple negative 15.5%. DISCUSSION Breast cancer is diagnosed at an earlier age among Brazilian patients. The majority of patients were detected through symptomatic BC and therefore a significant proportion is still diagnosed in stages III and IV. Among other factors, these findings could have a significant impact in treatment outcomes. Further analysis of this large cohort of patients will help to identify other important elements and direct future strategies for breast cancer control. TRIAL REGISTRY: NCT02663973 KEYWORDS: Breast Cancer; Epidemiology; Treatment; Brazil Citation Format: Rosa D, Barrios C, Bines J, Werustky G, Cronemberger E, Queiroz GS, Lima VC, Freitas-Júnior R, Couto J, Emerenciano K, Resende H, Crocamo S, Reinert T, Van Eyil B, Néron Y, Dybal V, Lazaretti N, Costamilan RC, Andrade DA, Mathias C, Vacaro GZ, Borges G, Torres KL, Morelle A, Sampaio Filho CA, Mano M, Zaffaroni F, Simon S. Current status of clinical and pathological characteristics of breast cancer patients in Brazil: Results of the AMAZONA III study (GBECAM 0115) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-29.