Breast Cancer Survival in Asian American Patients

Area of Science:

• Epidemiology
• Oncology
• Health Disparities

Background:

• Breast cancer mortality rates in the US are lower for Asian American females compared to other racial/ethnic groups, but the reasons remain unclear.
• Understanding these differences is crucial for addressing health disparities and improving breast cancer outcomes.

Purpose of the Study:

• To investigate the contributions of clinical, lifestyle, and sociodemographic factors to mortality differences in Asian American females versus non-Latina White females with breast cancer.
• To determine if these associations vary by nativity (place of birth).

Main Methods:

• A pooled cohort study analyzing survival data from 8994 females (3973 Asian, 5021 White) with breast cancer diagnosed between 1992-2019 from four epidemiologic studies.
• Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause and breast cancer-specific mortality, comparing Asian ethnic groups to White females, with adjustments for various prognostic factors.

Main Results:

• Several Asian groups, including Chinese, Filipina, Japanese, and those identifying with multiple Asian races/ethnicities, exhibited a lower risk of all-cause mortality compared to White females, even after full adjustment.
• This survival advantage persisted across different nativity statuses, with some groups born outside the US showing a lower adjusted risk.
• Asian groups were more likely to be diagnosed before age 50 and had lower proportions of localized stage disease compared to White females.

Conclusions:

• Even after accounting for clinical, sociodemographic, reproductive, lifestyle, and neighborhood factors, several Asian ethnic groups demonstrated a reduced risk of all-cause mortality post-breast cancer diagnosis.
• Identifying specific protective factors within these populations can offer valuable insights into mechanisms that enhance breast cancer survival.