Disaggregation of Asian American and Pacific Islander Women With Stage 0-II Breast Cancer Unmasks Disparities in Survival and Surgery-to-Radiation Intervals: A National Cancer Database Analysis From 2004 to 2017

Abstract

PURPOSE: Aggregation of Asian Americans (AAs) with Native Hawaiians and Other Pacific Islanders (NHPIs) masks significant health disparities. We evaluated overall survival (OS) and surgery-to-radiation intervals (STRIs) among AA and NHPI women with early-stage breast cancer. METHODS: This National Cancer Database study included women with stage 0-II breast cancer diagnosed between 2004 and 2017. STRI was defined as days from surgery to radiation. Patients were stratified by adjuvant treatment. AAs were disaggregated into geographically relevant subpopulations: East, South, and Southeast Asians. Kaplan-Meier estimates and log-rank tests assessed survival. Cox proportional hazard and linear regression were adjusted for clinical and sociodemographic factors. RESULTS: In total, 578,927 women were included (median age 61 years, median follow-up 65 months, and 10-year OS 83%). AA and NHPI 10-year OS was 91% overall; subpopulation 10-year OS was 92% for East Asian, 90% for South Asian, 90% for Southeast Asian, and 83% for NHPI. On multivariable analysis, compared with non-Hispanic White, NHPI women had worse survival (adjusted hazard ratio [aHR] = 1.38; 95% CI, 1.09 to 1.77); all AA subpopulations had improved survival: East Asian (aHR = 0.57; 95% CI, 0.48 to 0.69), South Asian (aHR = 0.66; 95% CI, 0.51 to 0.84), and Southeast Asian (aHR = 0.78; 95% CI, 0.65 to 0.94). The AA and NHPI median STRI for was 73 days overall; the disaggregated median STRI was 68 days for East Asian, 80 days for South Asian, 77 days for Southeast Asians, and 81 days for NHPI. On adjusted analysis, compared with non-Hispanic White, Southeast Asians and NHPI had longer STRI by 6.6 (95% CI, 4.3 to 8.9) and 10.0 (95% CI, 5.8 to 14) days, respectively. CONCLUSION: Breast cancer disparities exist among disaggregated AA and NHPI subpopulations. Data disaggregation insights may lead to interventions to overcome these disparities, such as optimizing time-to-treatment for select populations.

The Landmark Series: The Breast Cancer Burden of the Asian American Population and the Need for Disaggregated Data

“…Longer surgery-to-radiation intervals also have been reported for NHPI and South Asian (Indian and Pakistani) women than for NHW women. 44 …”

“…However, examination of subgroups shows a range of outcomes, dispelling our previous notion that AAPIs have better survival than their non-Asian counterparts. 8 , 30 , 44 A study by Medina et al 52 used data from the California Department of Public Health to examine cancer mortality in Asian ethnic subgroups compared with the NHW population. They found that BC mortality varied between subgroups, ranging from 8.6 per 100,000 (95% CI, 7.5–10.0) among Vietnamese women to 28.8 per 100,000 (95% CI, 24.0–34.2) among NHOPI women, the latter of whom had higher BC mortality than NHW women.…”

“… 52 This mortality gap also is evident when Native Hawaiians are compared with NHW women, as repeatedly demonstrated using Hawaii’s SEER registry as well as the NCDB. 11 , 44 , 53 Interestingly, the NCDB also showed that a South Asian (Asian Indian and Pakistani) cohort of women had improved overall survival and similar time to treatment compared with NHW women despite having higher rates of TNBC, a known prognosticator of poor survival. 44 , 54 These variations imply the existence of multiple unaccounted factors such as possible underreporting of survival statistics, barriers to access, social determinants of health, and cultural preferences that may contribute to these differences.…”

Breast Cancer Disparities in Asian Women: The Need for Disaggregated Research

“…Additionally, the aggregated 10-year survival of AZN BCa patients is greater than that of NH-White women (91% vs. 83%). Yet, in disaggregated analysis, Native Hawaiian and Other Pacific Islander (NHPI) patients have lower survival than other AZN women, as well as NH-White women [ 6 ].…”

“…The observed survival differences may be explained by delays in treatment among AZN ethnicities. Specifically, Southeast AZN and NHPI women have longer mean surgery-to-radiotherapy intervals than NH-White women by 6.6 and 10 days, respectively [ 6 ]. Similarly, another disaggregated study observed that Chinese women receive surgical treatment sooner than NH-White women, but minority AZN, Hispanic, and Black patients receive surgical treatment later [ 7 ].…”