Table 3. Cross-tabulation of ER co-expression in regard to OS and BCSS.
| ERβ1 positive | ERβ1 negative | |
|---|---|---|
| 10-year OS | ||
| ERα positive (%) | 91.4 | 85.4 |
| ERα negative (%) |
90.0 |
75.6 |
|
P-value |
0.050* |
|
| 10-year BCSS | ||
| ERα positive (%) | 93.9 | 91.0 |
| ERα negative (%) |
93.6 |
72.1 |
|
P-value |
0.009* |
|
| |
ERβcx positive |
ERβcx negative |
| 10-year OS | ||
| ERβ1 positive (%) | 92.0 | 95.5 |
| ERβ1 negative (%) |
78.1 |
100 |
|
P-value |
0.011* |
|
| 10-year BCSS | ||
| ERβ1 positive (%) | 95.9 | 92.3 |
| ERβ1 negative (%) |
80.0 |
100 |
|
P-value |
0.001* |
|
| 10-year OS | ||
| ERα positive (%) | 90.4 | 100 |
| ERα negative (%) |
84.6 |
90.0 |
|
P-value |
0.283 |
|
| 10-year BCSS | ||
| ERα positive (%) | 94.7 | 100 |
| ERα negative (%) |
86.0 |
85.7 |
| P-value | 0.093 | |
Abbreviations: BCSS=breast cancer-specific survival; ER=oestrogen receptor; OS=overall survival. The highest 10-year OS/BCSS was seen in ERα+/ERβ1+ tumours. Either ERα+/ERβ1− or ERα−/ERβ1+ was also associated with better prognosis, compared to double negative tumours (ERα−/ERβ1− that had the worst prognosis for both OS and BCSS. For ERβ and ERβcx co-expression, the worst 10-year OS/BCSS was seen in patients with ERβ1−/ERβcx+ tumours, compared to ERβ1+/ERβcx+, ERβ1+/ERβcx− and ERβ1−/ERβcx−. No significant differences in 10-year OS or BCSS were seen when comparing the co-expression of ERα and ERβcx. *P<0.05.