Table 1.
Differences in study design, experimental approaches and sample characteristics a
| Study demographics | PVLSI | SHL b [12] | UICH b [24] | PBCS cancer-adjacent normal tissue | PBCS tumor tissue |
|---|---|---|---|---|---|
| Cancer status |
Cancer-free |
Cancer-free |
Cancer-free |
Breast cancer |
Breast cancer |
| Tissue source |
Fresh whole tissue |
Core needle biopsies |
Microdissected FFPE tissue |
Fresh whole tissue |
Fresh whole tissue |
| Tissue enrichment |
Stroma |
Epithelial and stromal |
Epithelial |
Stroma |
Epithelial |
| Gene expression platform |
Agilent 4 × 44K |
GeneChip U133Plus 2.0 |
RT-PCR of 64 genes |
Agilent 4 × 44K |
Illumina |
| Samples |
|
|
|
|
|
| Total |
130 |
107 |
24 |
150 |
|
| ER+, n (%) |
N/A |
N/A |
N/A |
117 (78%) |
|
| Parous, n (%) |
76 (58%) |
67 (63%) |
11 (46%) |
119 (79%) |
|
| Premenopausal, n (%) |
84 (65%) |
0 (0%) |
24 (100%) |
41 (27%) |
|
| Mean age (±SD), yr |
37 (13) |
60 (5) |
29 (6) |
56 (10) |
|
| Mean BMI (±SD) | 30c (6) | 25 (4) | – | 28 (5) | |
a%, Percentage for categorical variables; BMI, Body mass index; FFPE, Formalin-fixed, paraffin-embedded; N/A, Not applicable; PBCS, Polish Breast Cancer Case–Control Study; PVLSI, Samples obtained from normal breast tissue of 130 women who underwent reduction mammoplasty surgery at Baystate Medical Center in Springfield, MA, USA, and banked at the Pioneer Valley Life Sciences Institute; SD, Standard deviation for continuous variables; SHL, Normal breast samples from 107 postmenopausal healthy volunteers recruited at the Sunderby Hospital in Luleå, Sweden; UICH, Mammoplasty benign biopsy specimens from 24 premenopausal women from the University of Illinois at Chicago Hospital. bFrom previously published, parity-related gene expression signatures in healthy women [12,24]. cThere were 56 (43%) missing BMI values in the PVLSI group.