Ethnic Differences in Mammographic Densities: An Asian Cross-Sectional Study

Shivaani Mariapun, Jingmei Li, Cheng Har Yip, Nur Aishah Mohd Taib, Soo-Hwang Teo, Chang-Qing Gao
2015 PLoS ONE  
Mammographic density is a strong risk factor for breast cancer and is highly variable, but, to date, few studies have examined density in Asian women, particularly those in low and middleincome Asian countries where genetic and lifestyle determinants may be significantly different. Methods A total of 1,240 women who attended an opportunistic mammogram screening programme were eligible for analysis. Mammographic density was estimated using a fully-automated thresholding method and differences
more » ... oss ethnic groups were examined using linear regression in 205 randomly selected Chinese women, 138 Malay and 199 Indian women. Results Percent density was significantly higher in Chinese women (28.5%; 95% CI 27.0%, 30.0%) compared to Malay (24.2%; 95% CI 22.5%, 26.0%) and Indian (24.3%; 95% CI 22.8%, 25.7%) women (p<0.001), after adjustment for age, BMI, menopausal status, parity and age at first full term pregnancy. Correspondingly, adjusted nondense area was significantly lower in Chinese (72.2cm 2 ; 95% CI 67.9cm 2 , 76.5cm 2 ) women compared to Malay (92.1cm 2 ; 95% CI 86.9cm 2 , 97.2cm 2 ) and Indian (97.7cm 2 ; 95% CI 93.4cm 2 , 101.9cm 2 ) women (p<0.001), but dense area did not differ across the three ethnic groups. Conclusions Our study shows that higher percent density and lower nondense area reflect the higher incidence of breast cancer in Chinese compared to Malay and Indian women in Malaysia. Known lifestyle determinants of mammographic density do not fully account for the ethnic variations observed in mammographic density in this Asian cohort. b Adjusted for variables associated with percent density [age, BMI, parity and age at first full term pregnancy] c Adjusted for variables associated with dense area [age, BMI and parity] d Adjusted for variables associated with non-dense area [age and BMI]
doi:10.1371/journal.pone.0117568 pmid:25659139 pmcid:PMC4320072 fatcat:as5yjrgg3rg57l5lspfgprgnwm