Table 5 Association between nuclear IRS‐1, oestrogen receptor α and tumour grade.
| Diagnostic marker | ROC analysis for tumour grade | ||
|---|---|---|---|
| AUC estimate (95% CI) | Area under the ROC curve | Mann–Whitney test (p value) | |
| Ductal carcinoma | |||
| ERα | 71.4 (41.9 to 91.4) | 0.809 | 0.001 |
| IRS‐1 | 78.6 (49.2 to 95.1) | 0.778 | 0.001 |
| Lobular carcinoma | |||
| ERα | 80.0 (28.8 to 96.7) | 0.817 | 0.02 |
| IRS‐1 | 60.0 (15.4 to 93.5) | 0.533 | 0.85 |
AUC, area under the receiver operating characteristic (ROC) curve; ERα, oestrogen receptor α; IRS‐1, insulin receptor substrate 1.
The analysis was performed with ROC curves, as described in Materials and methods section. The AUC describes the value of nuclear IRS‐1 or ERα to discriminate between G2 and G3 tumours. AUC estimate reports the CIs considering an error of 5%. The statistical significance was evaluated by Mann–Whitney U test for an area = 0.5.