Effects of Age, Breast Density and Volume on Breast Cancer Diagnosis: A Retrospective Comparison of Sensitivity of Mammography and Ultrasonography in China’s Rural Areas

Purpose: Mammography has been confirmed as the only effective mode to improve the prognosis of patientswith breast cancer in Western developed countries, but might not be a good choice in other areas of the world.One of the major challenges in China is to determine an optimal imaging modality for breast cancer screening.This study was designed to clarify the sensitivity of ultrasonography compared with that of mammography inrural China.
Methods: We retrospectively studied the sensitivity of mammography and ultrasonography basedon 306 breast cancer patients detected by the program of “screening for cervical cancer and breast cancer”performed in Chinese rural areas between January 2009 and December 2011, and analyzed the effects of age,breast density and volume on the sensitivity.
Results: Stratified analysis showed that the sensitivity of breastultrasonography was significantly higher than that of mammography in premenopausal patients (81.4% vs.61.1%, p=0.02), in women ≤ 55 years of age (82.2% vs. 63.4%, p<0.01), in the high breast density group (AmericanCollege of Radiology [ACR] levels 3-4) (85.9% vs. 60.6%, p<0.01) and in the small breast volume group (≤400ml) (87.1% vs. 66.7%, p<0.01). Age had a significant effect on sensitivity of mammography (breast density andvolume-adjusted odds ratio, 6.39; 95% confidence interval, 2.8-14.4 in age group > 55 compared to age group≤ 45), but not that of ultrasonography. Neither breast density nor volume had significant effect on sensitivityof mammography or ultrasonography.
Conclusions: Ultrasonography is more sensitive than mammography indetecting breast cancer in women under 55 year-old Chinese, especially in those with high-density and relativelysmall breasts.