Acculturation and Breast Density in Foreign-Born, U.S. Chinese Women

Abstract

The role of acculturation in the breast cancer risk increase among U.S. Chinese women is unclear. We examined the association between acculturation and breast density in a sample of foreign-born, U.S. Chinese women and examined factors that may explain such an association. Between January 2002 and May 2003, 212 Chinese women were recruited from Philadelphia region screening programs. Cranial-caudal mammographic images were classified into one of four categories ranging from ''entirely fatty'' to ''extremely dense.'' Questionnaires assessed information on sociodemographic, cultural, reproductive, and lifestyle factors. An index of acculturation was created based on selfreported English proficiency and within-and cross-ethnicity social interactions. To estimate odds ratios (OR) for falling into a higher versus lower category for breast density, we conducted logistic regression analysis using proportional odds models for polychotomous outcomes. We found that women in the highest acculturation category had denser breasts [age-adjusted OR, 3.1; 95% confidence interval (95% CI), 1.6-6.0]. They also had fewer live births, higher age at first live birth, and higher dairy food intake, all factors associated with breast density. In 196 women with complete covariate data, only adjustment for number of live births and dairy food intake attenuated the estimate for acculturation by >10%. With adjustment for both simultaneously, the most acculturated women were still more likely to have denser breasts (age-and menopause-adjusted OR, 2.0; 95% CI, 1.0-4.2). These analyses are the first to show breast density differences by level of acculturation among foreign-born, U.S. Chinese women. Despite reproductive and lifestyle differences by level of acculturation, differences in these factors did not explain the acculturation-breast density association. Future longitudinal research will examine whether the association is due to early-life factors, postmigration lifestyle changes, or perimenopausal exposures.

Breast cancer risk factors and a novel measure of volumetric breast density: cross-sectional study

“…Differences in an area-based measure of breast density and level of acculturation by Chinese women in the United States has been found (Tseng et al, 2006). This was only partially explained by risk factors (primarily parity and dairy food consumption).…”

Risk factors for breast cancer in the breast cancer risk model study of Guam and Saipan

“…A similar transition has occurred between 1975 and 2005 among Filipino women in Hawaii, where breast cancer incidence rates increased from 44 to 88, and among Native Hawaiian women, where the rates increased from 119 to 148. The transitional period may be especially risky (59–69). Incidence rates of breast cancer among Asian-American, Native Hawaiian, and Pacific Islander women increased between 2003 and 2012 as compared to non-Hispanic white women, and the reasons for this increase are thought to be related to changes in reproductive patterns and increased body weight that occur with acculturation after immigration (58).…”

“…Obesity, especially abdominal adiposity, is a risk factor for postmenopausal breast cancer (22, 23). Studies have shown that other ethnic groups (Japanese, Koreans, Chinese, Hispanics) experienced changes in diet and weight parameters as they migrated to the U.S. and became more acculturated into a Westernized life style (59, 60, 62, 65, 66, 68, 69) and that these changes affected their risk of cancer and other chronic diseases (61, 63, 64, 67). …”

Exploring the Underlying Hormonal Mechanisms of Prenatal Risk Factors for Breast Cancer: A Review and Commentary

“…High-density parenchymal patterns have also been considered a surrogate for mammary gland mass and are strongly associated with breast cancer risk (193,194). Interestingly, data show that among Chinese women who migrated to the United States, the most acculturated have the densest breasts, and that this is not explained by reproductive and lifestyle factors related to density (195). Whereas high-density patterns are a surrogate for the combination of the proportion of the breast occupied by epithelium and stroma (192), their correlation with actual ductal mass is unknown.…”