Nativity and Healthy Lifestyle Index in a Pooled Cohort of Female Breast Cancer Survivors from Northern California.

Background: In the United States, breast cancer is common in Asian, Hispanic, and non-Hispanic White (NHW) women, many of whom are immigrants. A healthy lifestyle is vital to survival, but it is unknown how lifestyle varies by nativity among survivors.

Methods: The study included 4,754 racially diverse, female breast cancer survivors from the Northern California, Exploring Networks in a Cohort of Latina and Asian Emigrants, Lifestyle, and Vital Status (ENCLAVE) study. We generated a healthy lifestyle index (HLI) based on World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations. Log-binomial regression models, controlling for sociodemographics, were used to evaluate associations between nativity and the highest tertile of HLI, as well as the optimal category of each HLI component.

Results: Foreign-born (vs. US-born) women were more likely to have a high HLI [prevalence ratio (PR) = 1.44; 95% confidence interval (CI), 1.31-1.59]. In stratified models, we observed stronger associations among Hispanic (PR = 1.76; 95% CI, 1.39-2.24) and Asian (PR = 1.60; 95% CI, 1.32-1.94) versus non-Hispanic White (PR = 1.26; 95% CI, 1.08-1.47) women (P-interaction = 0.02). Foreign-born (vs. US-born) women were more likely to have a waist circumference <31.5 inches (PR = 1.19; 95% CI, 1.03-1.37); be normal weight (PR = 1.23; 95% CI, 1.11-1.37); never smoke (PR = 1.11; 95% CI, 1.06-1.17); and consume no sweets (PR = 1.44; 95% CI, 1.21-1.70), low red meat (PR = 1.46; 95% CI, 1.33-1.60), and high fruits and vegetables (PR = 1.46; 95% CI, 1.32-1.62).

Conclusions: Among women diagnosed with breast cancer, foreign-born women had a healthier lifestyle than US-born women.

Impact: Lifestyle differences by nativity in breast cancer survivors may help clarify prognostic differences by nativity.