Background
Methods
Patient samples
Variable | Categorisation |
n
a
analysable | % |
---|---|---|---|
Clinicopathologic parameters:
| |||
Age at diagnosis: | median 57 years (range 28–87) | ||
<50 years | 53 | 31.2 | |
≥ 50 years | 117 | 68.8 | |
Tumour sizec
| |||
pT1 | 62 | 36.5 | |
pT2-4 | 91 | 53.5 | |
pT xb
| 17 | 10 | |
Lymph node statusc
| |||
pN0 | 74 | 43.5 | |
pN1-3 | 62 | 36.5 | |
pN x | 34 | 20 | |
Histological grade | |||
G1 | 14 | 8.2 | |
G2 | 79 | 46.5 | |
G3 | 61 | 35.9 | |
G x | 16 | 9.4 | |
Histological type | |||
invasive ductal | 128 | 75.3 | |
Invasive lobular | 18 | 10.6 | |
other | 24 | 14.1 | |
Oestrogen receptor status | |||
negative (IRSd 0–2) | 52 | 30.6 | |
positive (IRS 3–12) | 101 | 59.4 | |
IRS x | 17 | 10 | |
Progesterone receptor status | |||
negative (IRS 0–2) | 57 | 33.5 | |
positive (IRS 3–12) | 96 | 56.5 | |
IRS x | 17 | 10 |
Cell lines
DNA/RNA isolation of breast cancer cells
Reverse Transcription PCR
Semi-quantitative realtime PCR
Bisulphite-modification and methylation-specific PCR
5-aza-2'-deoxycytidine (DAC) and trichostatin A (TSA) treatment
Immunhistochemistry (IHC)
Statistical analyses of clinicopathological patient data
Results
ID4 methylation, expression and re-expression analysis of mammary cell lines
ID4 promoter methylation in primary human breast cancer
Correlation analyses between ID4 promoter methylation and ID4 expression in human breast cancer
Statistical analysis of clinicopathological patient data and patient survival
Variable |
ID4Methylation | |||
---|---|---|---|---|
na
| Positive | Negative | P-valued
| |
Total
| 170 | 117 | 53 | |
Clinicopathological parameters:
| ||||
Age at diagnosis | ||||
<50 years | 51 | 34 | 17 | 0.821 |
≥ 50 years | 111 | 76 | 35 | |
Tumour sizeb
| ||||
pT1 | 62 | 24 | 44 | 0.247 |
pT2-4 | 91 | 27 | 7 | |
Lymph node statusb
| ||||
pN0 | 74 | 43 | 31 |
0.030
|
pN1-3 | 62 | 47 | 15 | |
Histological grade | ||||
G1 | 14 | 10 | 4 | 0.944 |
G2 | 79 | 52 | 27 | |
G3 | 61 | 42 | 19 | |
Histological type | ||||
invasive ductal | 129 | 87 | 42 | 0.940 |
invasive lobular | 18 | 12 | 6 | |
other | 12 | 8 | 4 | |
Oestrogen receptor status | ||||
negative (IRSc 0–2) | 52 | 35 | 17 | 0.900 |
positive (IRS 3–12) | 101 | 69 | 32 | |
Progesterone receptor status | ||||
negative (IRS 0–2) | 57 | 39 | 18 | 0.920 |
positive (IRS 3–12) | 96 | 65 | 31 | |
ID4 mRNA expression x-fold | ||||
FC<2 | 8 | 0 | 8 |
<0.001
|
FC≥2 | 38 | 31 | 7 |
Variable | RFS | OS | ||||
---|---|---|---|---|---|---|
na
| events | P-valued
| n | events | P-value | |
Clinicopathological factors:
| ||||||
Tumour sizeb
| ||||||
pT1 | 44 | 14 | 0.142 | 45 | 7 | 0.396 |
pT2-4 | 77 | 35 | 79 | 16 | ||
Lymph node statusb
| ||||||
pN0 | 55 | 11 |
0.021
| 54 | 6 |
0.033
|
pN1-3 | 59 | 24 | 59 | 15 | ||
Histological grade | ||||||
G1 | 11 | 3 |
0.018
| 10 | 1 |
0.019
|
G2 | 60 | 15 | 58 | 7 | ||
G3 | 60 | 30 | 54 | 17 | ||
Histological type | ||||||
invasive ductal | 107 | 33 |
0.006
| 106 | 23 | 0.877 |
invasive lobular | 18 | 9 | 18 | 2 | ||
other | 9 | 7 | 9 | 2 | ||
Oestrogen receptor status | ||||||
negative (IRSc 0–2) | 46 | 15 | 0.701 | 45 | 12 |
0.027
|
positive (IRS 3–12) | 82 | 32 | 82 | 14 | ||
Progesterone receptor status | ||||||
negative (IRSc 0–2) | 43 | 18 | 0.240 | 43 | 11 | 0.059 |
positive (IRS 3–12) | 85 | 29 | 84 | 15 | ||
ID4 promoter methylation | ||||||
negative | 39 | 8 |
0.036
| 39 | 5 | 0.169 |
positive | 76 | 28 | 75 | 16 |