e23313 Background: Breast cancer incidence in the Philippines is among the highest in Asia - the WHO reported it to be as high as 33,079 in 2022. Data provided by the Philippine Cancer Society and Department of Health Rizal Cancer Registry in 2009 included 1,615 breast cancer patients and noted a significant increase in breast cancer incidence from the year 1980 to 2002 in 7 cities in Metro Manila. This retrospective study aims to describe and analyze clinicopathologic and treatment data of Filipino breast cancer patients in a tertiary hospital. This study represents the largest pooled data in the Philippines on breast cancer demographics. Methods: Patients diagnosed with invasive breast cancer in St. Luke’s Medical Center (SLMC) from 2009 to 2020 were included. Patients diagnosed with other breast histopathologic results [i.e. ductal and lobular carcinoma in situ without invasive component] and double primaries were excluded. The study was approved by the Ethics Review Committee (Reference No.: SL-19157). Results: A total of 5,462 breast cancer patients were included. Majority of the patients were late perimenopausal (50-59 yo, 30.06%), menopausal (60-69 yo, 23.03%), and premenopausal (below 44 yo, 19.28%,) at the time of diagnosis. Patients were diagnosed with stage II (N = 1,816, 47.24%), followed by stage I (N = 943, 24%), and stage III (N = 662, 17%). Sixty four percent (N = 1,498) were node negative while 46% (N = 1,300) were node positive. Among patients with de novo metastasis, 14.6% metastasized to the bone while visceral sites include chest wall (17.4%), lung (16.6%), liver (11.5%) and brain (7.45%). Luminal her2- (48.9%) was the most common clinical subtype followed by non-luminal her2+ (15.6%) and triple negative (6.7%). Definitive surgery was the mainstay of treatment – 94% (N = 4116) underwent modified radical mastectomy (MRM) while 5% (N = 223) underwent breast conserving surgery (BCS). Eight hundred patients (19%) received neoadjuvant treatment (hormonal and/or systemic chemotherapy) while 2,246 patients (54%) received adjuvant treatment. Total number of breast cancer patients who underwent adjuvant radiation was 1,399 (25.6%). Conclusions: Compared to middle-high income countries, data suggests that MRM is the preferred surgical technique over BCS. Majority of patients in the study are luminal her2-. However, only 54% received adjuvant treatment. Another observation is the low rate of neoadjuvant treatment by the study population. Further research on the risk factors or reasons for not receiving treatment as well as the outcomes of these patient cohorts is needed to shed light on these cancer care gaps.