Abstract PR-15: Disaggregating Asian American and Pacific Islanders unmasks disparities in survival, time-to-surgery, and surgery-to-radiation intervals among women with Stage I-III breast cancer: An NCDB analysis from 2004-2016
Authors: Taparra Kekoa , Dee Edward Christopher , Dao Dyda , Patel Rohan , Santos Patricia , Chino Fumiko 
Published: January 2022

INTRODUCTION The aggregation of Asian Americans (AA) with Native Hawaiian and other Pacific Islanders (NHPI) masks health disparities. Few studies have appropriately disaggregated AA & NHPI patients with breast cancer. The purpose of this study was to evaluate 1) survival outcomes, 2) times-to-surgery (TTS), & 3) surgery-to-radiation intervals (STRI) among AA & NHPI women with non-metastatic breast cancer. Methods This was an IRB exempt, retrospective cohort study using the National Cancer Database of women diagnosed with stage I-III breast cancer in 2004-2016 with AA & NHPI were compared to Non-Hispanic White (NHW). TTS (diagnosis date to surgery date) & STRI (surgery date to radiation date) were calculated. STRI was stratified by adjuvant radiotherapy (STRI-R) or adjuvant chemotherapy-followed-by-radiotherapy (STRI-CR). AA was separated geographically: East Asian (EA; Chinese, Japanese, Korean), South Asian (SA; Indian, Pakistani), & Southeast Asian (SEA; Filipino, Vietnamese, Laotian, Hmong, Cambodian). Log-rank tests assessed survival. Linear regressions assessed adjusted coefficients (β) with 95% confidence intervals (95%CI). Analyses were adjusted for patient factors (age, urban/rural, income, education, comorbidities) & cancer characteristics (stage, pathology, diagnosis year). P&lt;.05 was used for significance & multivariable co-variable selection. Results 1,407,523 women were included: 1,361,215 NHW, 3,579 NHPI, 19,422 EA, 8,569 SA, & 14,738 SEA. Median follow-up was 69 months (IQR=41-106). 15-year survival (95%CI) was 60% (60-61%) for NHW, 66% (55-78%) for NHPI, 77% (72-82%) for SEA, 77% (73-81%) for EA, & 84% (82-87%) for SA, p&lt;.001. On adjusted analysis, compared to NHW, all AA subgroups had improved survival (EA HR=0.63, 95%CI=0.57-0.70; SA HR=0.74, 95%CI=0.64-0.87; SEA HR=0.67, 95%CI=0.59-0.75). NHPI was not significantly different (HR=1.06, 95%CI=0.88-1.27). Median TTS was 25 days (IQR=13-40 days). On adjusted analysis compared to NHW, TTS was significantly longer for NHPI (β=3.4 days; 95%CI=1.9-4.9 days) & SEA (β=5.0 days; 95%CI=4.3-5.8 days), with no differences in TTS for EA & SA. Median STRI-R was 49 days (IQR=38-67 days). On adjusted analysis compared to NHW, STRI-R was significantly longer for NHPI (β=6.8 days, 95%CI=3.6-9.9 days), SEA (β=6.3 days, 95%CI=4.5-8.0 days), & EA (β=2.1 days, 95%CI=0.65-3.5 days), with no difference in STRI-R for SA. Median STRI-CR was 181 days (IQR=152-216 days). On adjusted analysis compared to NHW, STRI-CR was significantly longer for NHPI (β=11 days, 95%CI=6.1-17 days) & SEA (β=4.1 days, 95%CI=1.3-6.9 days). No difference in STRI-CR were seen for EA & SA. Conclusions The data reveal disparities among women with breast cancer for survival, time-to-surgery, & surgery-to-radiation intervals among NHPI & three major AA subgroups. Improper aggregation, particularly for NHPI & SEA, masks these disparities. Through proper disaggregation, solutions may be identified to abrogate overlooked racial disparities among minority women with breast cancer, such as longer times to treatment.

Citation Format: Kekoa Taparra, Edward Christopher Dee, Dyda Dao, Rohan Patel, Patricia Santos, Fumiko Chino. Disaggregating Asian American and Pacific Islanders unmasks disparities in survival, time-to-surgery, and surgery-to-radiation intervals among women with Stage I-III breast cancer: An NCDB analysis from 2004-2016 [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PR-15.