Introduction
Materials and methods
Breast cancer samples
Total cohort | Non-radiotherapy-treated | Radiotherapy-treated | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Low BRE
a (N = 115) | High BRE
a (N = 114b) |
p
| Low BRE
a (N = 32) | High BRE
a (N = 27b) |
p
| Low BRE
a (N = 83) | High BRE
a (N = 86b) |
p
| |||||||
Age (N = 229), mean (range) | 59.9 | (31–88) | 59.2 | (32–86) | 0.775d
| 63.0 | (33–88) | 61.5 | (35–86) | 0.784d
| 58.7 | (31–85) | 58.3 | (32–83) | 0.816d
|
Menopausal status (N = 229) | 1.000e
| 1.000e
| 1.000e
| ||||||||||||
Premenopausal, no. (%) | 29 | (25.2) | 28 | (24.6) | 6 | (18.8) | 5 | (18.5) | 23 | (27.7) | 23 | (26.7) | |||
Postmenopausal, no. (%) | 86 | (74.8) | 86 | (75.4) | 26 | (81.3) | 22 | (81.5) | 60 | (72.3) | 63 | (73.3) | |||
Nodal category (N = 208) | 0.923e
| 0.310e
| 0.806e
| ||||||||||||
Negative, no. (%) | 61 | (58.1) | 59 | (57.3) | 25 | (86.2) | 18 | (72.0) | 36 | (47.4) | 41 | (52.6) | |||
1–3 involved lymph nodes, no. (%) | 29 | (27.6) | 31 | (30.1) | 4 | (13.8) | 7 | (28.0) | 25 | (32.9) | 24 | (30.8) | |||
≥4 involved lymph nodes, no. (%) | 15 | (14.3) | 13 | (12.6) | 0 | (0) | 0 | (0) | 15 | (19.7) | 13 | (16.7) | |||
Radiotherapy (N = 228) | 0.547e
| NA | NA | ||||||||||||
Treated, no. (%) | 83 | (72.2) | 86 | (76.1) | 0 | (0) | 0 | (0) | 83 | (100) | 86 | (100) | |||
Non-treated, no. (%) | 32 | (27.8) | 27 | (23.9) | 32 | (100) | 27 | (100) | 0 | (0) | 0 | (0) | |||
Surgery (N = 229) | 0.282e
| 0.495f
| 0.219f
| ||||||||||||
Mastectomy, no. (%) | 73 | (63.5) | 64 | (56.1) | 30 | (93.8) | 27 | (100) | 43 | (51.8) | 36 | (41.9) | |||
Lumpectomy, no. (%) | 42 | (36.5) | 50 | (43.9) | 2 | (6.3) | 0 | (0) | 40 | (48.2) | 50 | (58.1) | |||
Adjuvant systemic therapy (N = 228) | 0.230f
| 0.537f
| 0.269f
| ||||||||||||
None, no. (%) | 70 | (60.9) | 68 | (60.2) | 26 | (81.3) | 18 | (66.7) | 44 | (53.0) | 50 | (58.1) | |||
Endocrine therapy, no. (%) | 30 | (26.1) | 28 | (24.8) | 3 | (9.4) | 4 | (14.8) | 27 | (32.5) | 24 | (27.9) | |||
Chemotherapy, no. (%) | 13 | (11.3) | 9 | (8.0) | 2 | (6.3) | 2 | (7.4) | 11 | (13.3) | 7 | (8.1) | |||
Endocrine + Chemotherapy, no. (%) | 2 | (1.7) | 8 | (7.1) | 1 | (3.1) | 3 | (11.1) | 1 | (1.2) | 5 | (5.8) | |||
Histology grade (N = 168) | 0.406e
| 0.151f
| 0.123e
| ||||||||||||
I, no. (%) | 9 | (10.5) | 4 | (4.9) | 1 | (4.3) | 1 | (5.3) | 8 | (12.7) | 3 | (4.8) | |||
II, no. (%) | 36 | (41.9) | 35 | (42.7) | 6 | (26.1) | 10 | (52.6) | 30 | (47.6) | 25 | (39.7) | |||
III, no. (%) | 41 | (47.7) | 43 | (52.4) | 16 | (69.6) | 8 | (42.1) | 25 | (39.7) | 35 | (55.6) | |||
Tumor type (N = 193) | 0.744e
| 0.721f
| 1.000e
| ||||||||||||
Ductal, no. (%) | 73 | (73.0) | 70 | (75.3) | 22 | (71.0) | 18 | (81.8) | 51 | (73.9) | 52 | (73.2) | |||
Lubular, no. (%) | 15 | (15.0) | 15 | (16.1) | 3 | (9.7) | 2 | (9.1) | 12 | (17.4) | 13 | (18.3) | |||
Other (mixed/unknown), no. (%) | 12 | (12.0) | 8 | (8.6) | 6 | (19.3) | 2 | (9.1) | 6 | (8.7) | 6 | (8.5) | |||
Tumor size (N = 227)c
| 0.014f
| 0.853f
| 0.005e
| ||||||||||||
pT1, no. (%) | 33 | (28.7) | 50 | (44.6) | 11 | (34.4) | 9 | (33.3) | 22 | (26.5) | 41 | (48.2) | |||
pT2, no. (%) | 66 | (57.4) | 43 | (38.4) | 19 | (59.4) | 15 | (55.6) | 47 | (56.6) | 28 | (32.9) | |||
pT3/4, no. (%) | 16 | (13.9) | 19 | (17.0) | 2 | (6.3) | 3 | (11.1) | 14 | (16.9) | 16 | (18.8) | |||
Estrogen receptor status (N = 196) | 0.769e
| 0.265e
| 0.228e
| ||||||||||||
Positive, no. (%) | 61 | (61.0) | 61 | (63.5) | 18 | (66.7) | 12 | (50) | 43 | (58.9) | 49 | (69.0) | |||
Negative, no. (%) | 39 | (39.0) | 35 | (36.5) | 9 | (33.3) | 12 | (50) | 30 | (41.1) | 22 | (31.0) | |||
Progesterone receptor status (N = 197) | 0.776e
| 0.579e
| 1.000e
| ||||||||||||
Positive, no. (%) | 51 | (50.5) | 51 | (53.1) | 12 | (44.4) | 13 | (54.2) | 39 | (52.7) | 38 | (53.5) | |||
Negative, no. (%) | 50 | (49.5) | 45 | (46.9) | 15 | (55.6) | 11 | (45.8) | 35 | (47.3) | 33 | (46.5) |
BRE QPCR
Statistical analyses
Results
BRE expression correlates with tumor size
BRE expression predicts DFS in breast cancer
Total cohort | Non-radiotherapy-treated patients | Radiotherapy-treated patients | ||||
---|---|---|---|---|---|---|
p
| HR (95 % CI) |
p
| HR (95 % CI) |
p
| HR (95 % CI) | |
BRE expression (QPCR data) | 0.342 | 0.877 (0.67–1.15) | 0.016 | 1.79 (1.11–2.87) | 0.030 | 0.72 (0.53–0.97) |
Non-radiotherapy-treated patients | Radiotherapy-treated patients | |||||||
---|---|---|---|---|---|---|---|---|
Univariate | Multivariatea
| Univariate | Multivariatea
| |||||
p
| HR (95 % CI) |
p
| HR (95 % CI) |
p
| HR (95 % CI) |
p
| HR (95 % CI) | |
BRE
| 0.059e
| 2.51 | 0.083e
| 2.38 | 0.004 | 0.46 | 0.021 | 0.50 |
(2 groupsb) | (0.97–6.53) | (0.89–6.35) | (0.27–0.79) | (0.27–0.90) | ||||
Age | 0.349 | 0.98 | 0.616 | 0.99 | 0.112 | 0.98 | 0.020 | 0.97 |
(continuous) | (0.95–1.02) | (0.95–1.03) | (0.96–1.00) | (0.95–1.00) | ||||
Menopausal status | 0.838 | 1.07 | 0.140 | 0.81 | ||||
(post- vs. premenopausal) | (0.57–1.99) | (0.62–1.07) | ||||||
Tumor sizec
| 0.422 | 1.39 | 0.465 | 1.56 | <0.001 | 2.01 | 0.014 | 1.70 |
(pT1 vs. pT2 vs. pT3/4) | (0.62–3.09) | (0.47–5.15) | (1.42–2.84) | (1.11–2.59) | ||||
Histological grade | 0.941 | 0.97 | 0.895 | 1.01 | 0.032 | 1.70 | 0.313 | 0.95 |
(I vs. II vs. III vs. NDd) | (0.39–2.42) | (0.86–1.19) | (1.05–2.74) | (0.86–1.05) | ||||
Involved lymph nodes | 0.002 | 5.63 | 0.034 | 3.92 | 0.001 | 1.87 | 0.013 | 1.66 |
(0 vs. 1–3 vs. ≥ 4) | (1.84–17.3) | (1.11–13.8) | (1.30–2.68) | (1.11–2.48) | ||||
Estrogen receptor status | 0.680 | 0.82 | 0.362 | 0.78 | ||||
(positive vs. negative) | (0.31–2.15) | (0.45–1.34) | ||||||
Progesterone receptor status | 0.866 | 0.92 | 0.839 | 0.95 | ||||
(positive vs. negative) | (0.36–2.39) | (0.55–1.62) |