Background Randomised clinical trials (RCT) are considered a gold standard generating efficacy and safety data supporting drug approval. However, real world data (RWD) reflecting health care delivery is becoming increasingly important. RWD on patient profiles and patterns of care in MBC are scarce in developing countries. As an example, observational studies suggest that despite guideline recommendations clearly indicating ET for hormone receptor positive MBC, a considerable proportion of patients in clinical practice begin chemotherapy in early lines of therapy. This pragmatic information addresses the uptake and applicability of the RCT results and should be able to help informing health care planning complementing RCT generated data. The objective of this study is to describe patient characteristics and evaluate actual physician-reported treatments for MBC in Brazil. Methods This analysis addresses the first 362 patients included in LACOG-0312, a retrospective study planning to recruit over 700 patients (cut-off date April 30th 2016) with recurrent locally advanced or MBC diagnosed in 2012 in 18 institutions across Brazil. Patient characteristics, type of health insurance coverage, treatment and survival outcome were analysed. Results Median age at BC diagnosis was 53 years and 37% were premenopausal. Regarding the educational level, 63.2% had completed elementary (primary) schooling, 75.7% were covered by the public health system while 24.3% had some form of private coverage. 70% of patients had hormone receptor positive (HR+) and 18% had HER2 positive tumors. Median disease free survival time from surgery was 29 months. Interestingly, 30% of patients underwent a biopsy of a metastatic site. Of the 362 patients, 349 (96.9%) received some form of palliative systemic therapy. Median time from diagnosis of metastatic disease to first-line therapy initiation was 46 days but a significant difference was noted between patients with public versus private health insurance (50 vs. 33 days p=0.012). Half of the patients received at least 3 lines of therapy (chemo or endocrine) to a maximum of 9 lines. In patients with HR+ tumors, endocrine therapy was administered in 47% in first, 65% in second and 61% in third-line, respectively. Median overall survival (OS) from diagnosis of metastatic disease was 34 months (CI 95%: 25.7-44.3) and no differences in OS were observed between patients with public or private coverage (34 months vs. 35 months p=0.808). Causes of death were cancer in 85.2% of patients and treatment toxicity in 3.6%. Conclusion Our study included a population with predominantly low educational level and mostly public health insurance. This likely corresponds to the majority of cases and reflects cancer care patterns in Brazil and many developing countries. A considerable proportion of patients were premenopausal at MBC diagnosis. More than half of HR+ patients received at least 3 lines of endocrine therapy although 54% of them had chemotherapy as the first systemic treatment. Patients from the public health system experienced a delay in starting first-line therapy but this didn't seem to jeopardize cancer outcomes in this setting. Citation Format: Barrios CH, Uema D, Cronenberger E, Lima V, Bines J, de Sant'ana RO, Batista ML, Dybal V, Liedke P, Beato C, Nerón YV, Giacomazzi J, dos Santos L, Ismael G, Azambuja A, Andrade D, Rosa DD, Borges G, Mano M, Martinez-Mesa J, Zaffaroni F, Werutsky G. Real World data and patterns of care of metastatic breast cancer (MBC) in Brazil: First results of LACOG 0312 retrospective study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-16-04.