Effects of Stressors On Psychological Outcomes Among Chinese- and Korean-American Breast Cancer Survivors

Stressors, which have been concerned with internal and external events that are taxing to individuals, have potential to induce poor psychological outcomes, such as depressive symptoms. Previous studies consistently demonstrate that breast cancer survivors (BCS) experience significant stressors that impact multiple dimensions of psychological outcomes. However, little is known about sources of stress faced by BCS and few studies examine the associations between stressor factors and psychological outcomes in Chinese- and Korean-American BCS. The purpose of this study is 1) to explore the underlying factor structures of stress and concern related items and 2) to examine the effects of stressor factors on psychological outcomes (mental health status, psychological distress) in Chinese- and Korean-American BCS.

A cross-sectional survey design was utilized. A total of 157 Chinese- (n=86) and Korean-American BCS (n=71) were recruited through the California Cancer Surveillance Program, area hospitals, and community agencies in Los Angeles County. Stressors were measured by Life Stress Scale and FACT-B additional concern subscale. Psychological outcomes were measured with the SF-36 mental health summary score (mental health status) and Brief Symptom Inventory-18 (psychological distress).

The mean ages of the Chinese- and Korean-American BCS were 55.2 and 53.9 years, respectively. Most demographic characteristics (age, household income, years lived in the U.S) were not varied significantly between Chinese- and Korean-Americans. However, there were significant ethnic differences in acculturation level and medical characteristics (cancer stage, years since diagnosis).

To explore the factor structures of stressors, exploratory factor analysis was conducted using principal component analysis with varimax rotation, after creating standardized z scores to combine two different measures. Four components were extracted with Eigen values greater than or equal to one. The total variance explained by these four factors combined was 67.73%: concerns about survivorship care (5 items, with explained variances of 34.15%), functional stress (4 items: money/finances, housing/living situation, job situation, education, with explained variances of 15.01%), stressful family life event (2 items, with explained variances of 9.95%), and self-image (2 items, with explained variances of 8.61%). To obtain the composite score on each factor, corresponding standardized scores were averaged.

Hierarchical multiple regression analyses were then conducted to identify effects of stressor factors on psychological outcomes for Chinese- and Korean-American BCS separately, after adjusting for covariates (age, household income, years lived in U.S, acculturation, comorbidity, cancer stage, surgery type, years since diagnosis). Functional stress, self-image, and stressful life event factors significantly predicted mental health status and psychological distress among Chinese-American BCS only. For Korean-Americans, concerns about survivorship care significantly influenced, but other factors did not. Regression models for Chinese- and Korean-Americans accounted for 62.5% and 58.6% of the variance in mental health status and 63.7% and 56.5% of the variance in psychological distress, respectively.

Our study explored four stressor factors BCS face following breast cancer treatment, and demonstrated that types of stressors which may influence psychological outcomes vary between Chinese- and Korean-Americans. Identifying stress factors across ethnicity would provide better understanding of stressors and contribute to developing culturally and ethnically appropriate intervention strategies for Chinese- and Korean-American BCS.