UC Irvine

Background

Emerging evidence has indicated that Middle Eastern (ME) immigrants might be more likely to be diagnosed with breast cancer at advanced stage, yet have better overall survival than nonimmigrant non-Hispanic whites (NHW). This study aims to analyze the association between ME immigration status and breast cancer stage at diagnosis and survival.

Methods

Using the California Cancer Registry, a total of 343 876 women diagnosed with primary in situ or invasive breast cancers were identified during 1988-2013. Multinomial logistic regression models were fitted to evaluate the risk of in situ and nonlocalized breast cancer stage in comparison with localized breast cancer among first-generation ME immigrants, second- or subsequent-generation ME immigrants, and NHW. Cox proportional hazard models were applied to calculate hazard ratios (HRs) with their 95% confidence intervals (CIs) for breast cancer mortality among the three population groups with invasive primary breast cancer.

Results

First-generation ME immigrants had higher odds of being diagnosed with a nonlocalized stage (vs localized) than NHW (odds ratio [OR] = 1.17, 95% CI = 1.09 to 1.26). Second- or subsequent-generation ME immigrants also had higher odds of being diagnosed with a nonlocalized stage (vs localized) than NHW (OR = 1.31, 95% CI = 1.20 to 1.43). First-generation ME immigrants were 11% less likely to die from breast cancer than NHW (HR = 0.89, 95% CI = 0.82 to 0.97).

Conclusions

First-generation ME immigrants had higher breast cancer survival despite being diagnosed at a nonlocalized breast cancer stage at diagnosis when compared with NHW. Screening interventions tailored to this ME immigrant group need to be implemented.