The relationship between terminal duct lobular unit features and mammographic density among Chinese breast cancer patients

Abstract

Extensive mammographic density (MD), a well‐established breast cancer risk factor, is a radiological representation of stromal and epithelial breast tissue content. In studies conducted predominantly among Caucasian women, histologic measures of reduced terminal duct lobular unit (TDLU) involution have been correlated with extensive MD, but independently associated with breast cancer risk. We therefore examined associations between TDLU measures and MD among Chinese women, a low‐risk population but with high prevalence of dense breasts. Diagnostic pre‐treatment digital mammograms were obtained from 144 breast cancer cases at a tertiary hospital in Beijing and scored using the Breast Imaging Reporting and Data System (BI‐RADS) density classification. TDLU features were assessed using three standardized measures (count/100 mm2, span [μm], and acini count/TDLU) in benign tissues. Associations between each of TDLU measures and MD were examined using generalized linear models for TDLU count and span and polytomous logistic regression for acini count with adjustment for potential confounders stratified by age. Among women ≥50 years, 63% had dense breasts; cases with dense breasts (BI‐RADS, c‐d) had greater TDLU count (21.1 [SE = 2.70] vs. 9.0 [SE = 1.83]; p = 0.0004), longer span (480.6 μm [SE = 24.6] vs. 393.8 μm [SE = 31.8]; p = 0.03), and greater acini count (ORtrend = 16.1; 95%CI = 4.08–63.1; ptrend < 0.0001) compared to those with non‐dense breasts (BI‐RADS, a‐b). Among women <50 years, 91% had dense breasts, precluding our ability to detect associations. Our findings are consistent with previously reported associations between extensive MD and reduced TDLU involution, supporting the hypothesis that breast cancer risk associated with extensive MD may be related to the amount of “at‐risk” epithelium.

Involution of Breast Lobules, Mammographic Breast Density and Prognosis Among Tamoxifen-Treated Estrogen Receptor-Positive Breast Cancer Patients

“…Although associations of TDLU involution with age and MD were as expected in our study, we observed a higher proportion of pathology specimens containing TDLUs than prior reports [24,30,31,32]. In contrast to prior reports [31], our population differed in that it was nearly exclusively white and included the highest proportion of obese women.…”

Deep Learning Image Analysis of Benign Breast Disease to Identify Subsequent Risk of Breast Cancer

“…The strengths of our study include the application of a computer pathology method to assess breast tissue composition in a large study with rich data on risk factors ( 2 , 3 , 24 , 32 , 33 , 40 ), BBD samples underwent centralized pathology review, and BC cases were confirmed through review of medical records. Some limitations of our study include being underpowered to evaluate the association of breast composition and ER-negative BC, BC molecular subtypes ( 75 , 76 ), or mammographic density ( 77 , 78 ) because mammogram data were available for only 105 women (7.8%) in this study. Our findings were limited to White women, the predominant race of the NHS and NHSII participants.…”

Deep Learning Image Analysis of Benign Breast Disease to Identify Subsequent Risk of Breast Cancer

“…BBD samples underwent centralized pathology review and breast cancer cases were confirmed through review of medical records. Some limitations of our study include being underpowered to evaluate the association of breast composition and ER negative breast cancer, breast cancer molecular subtypes 71,72 , or mammographic density 73,74 as mammogram data were only available for 105 women (7.8%) in this study. Our findings were also limited to White women, the predominant race of the NHS/NHSII participants.…”