Abstract 890: Addressing heterogeneity in breast cancer outcomes and patterns of care among Asian Americans in Los Angeles: the AMBER-LA Study.

Abstract Background: Breast cancer (BC) is the most diagnosed cancer among Asian American (AA) women, and its incidence continues to rise rapidly. Although emerging evidence suggests variation in cancer outcomes across AA groups, most studies have aggregated Asians into one category. To address this gap, we aimed to build a cohort of diverse AA BC patients to characterize ethnic group-specific patterns of care and cancer outcomes. Methods: The Asian American Breast Cancer Research in Los Angeles (AMBER-LA) is an exploratory study assessing the feasibility of recruiting AA BC patients to identify multilevel factors associated with care and disease prognosis. Chinese, Korean, and Filipino women aged 21-75 years, residing in Los Angeles County, and diagnosed with invasive BC since January 2021, were recruited from a large academic health center and community outreach events. Data on demographics, cancer diagnosis, and patterns of care were collected through surveys and medical record abstractions. Differences across AA groups were examined using Fisher’s exact test. Findings: Among the 51 participants enrolled to date, including 19 Chinese, 11 Filipino and 21 Korean women, most (94.1%) were recruited from telephone and in-person outreach within clinic settings, and 88.2% were born outside the US. Although 72.5% completed the survey in English, only 17.6% prefer English in their daily life. The mean age at diagnosis was 53.0 years (SD: 10.8). Although not statistically significant, Filipino participants in this sample were more likely to be diagnosed before the age 50, compared with other groups. Modes of diagnosis were similar across groups, with half being detected through routine screening and half after seeking care for symptoms. The median time from abnormal results to seeing a specialist was 21 days (IQR: 10-32). Compared with other groups, Korean participants were more likely to be referred within two weeks, although the differences were not significant. Although 98.0% of participants reported being insured, 15.7% of them reported delaying or not receiving care due to cost in the past year. Alarmingly, experience of discrimination during care was reported by 68.4% of Chinese, 36.4% of Filipino and 42.9% of Korean participants. The most frequently reported experience differed by AA groups: Chinese participants reported not being listened to, Filipino participants reported being treated with less courtesy, and Korean participants described feeling inferior. Conclusion: Recruiting AA BC patients was challenging, however, engagement with healthcare providers made it feasible. Preliminary evidence of younger age at diagnosis, variation in referral interval, and differential experience of discrimination highlight the need for culturally relevant, group-specific care strategies to improve patient experience and quality of care for AA women. Citation Format: Junrui Lyu, Kelsey Lam, Grace Guo, Andrei Mikhael Galura, Emily Kumagai, Bodour Salhia, Evanthia T. Roussos Torres, Chanita Hughes-Halbert, Veronica Wendy Setiawan, Jennifer Tsui. Addressing heterogeneity in breast cancer outcomes and patterns of care among Asian Americans in Los Angeles: the AMBER-LA Study abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 890.