Table 1
Clinical and tumour characteristics
| CONTINUOUS VARIABLES | Mean | SD | Median | Range |
|---|---|---|---|---|
| AGE (years) | 47.22 | 10.10 | 42.0 | 31.0–75.0 |
| BASAL TUMOR SIZE (cm) | 3.99 | 1.97 | 3.40 | 1.60–13.0 |
| CATEGORICAL VARIABLES | n | % | 95% CI | |
|---|---|---|---|---|
| CLINICAL TUMOR STAGE | T1 | 7 | 7.6 | 1.6–13.6 |
| T2 | 69 | 75.0 | 65.6-84.4 | |
| T3 | 13 | 14.1 | 6.5–21.8 | |
| T4 | 3 | 3.3 | 0.7–9.2 | |
| HISTOLOGICAL TYPE | Ductal | 85 | 92.4 | 86.4–98.4 |
| Lobular | 7 | 7.6 | 1.6–13.6 | |
| HISTOLÓGICAL GRADE | G1 | 9 | 10.0 | 3.2-16.8 |
| G2 | 32 | 35.6 | 25.1-46.0 | |
| G3 | 49 | 54.4 | 43.6-65.3 | |
| NA | 2 | |||
| HORMONAL RECEPTOR STATUS | Positive | 60 | 65.2 | 54.9-75.5 |
| Negative | 32 | 34.8 | 24.5-45.1 | |
| HER2 STATUS | Positive | 25 | 27.2 | 17.5-36.8 |
| Negative | 67 | 72.8 | 63.2-82.5 | |
| MOLECULAR SUBTYPE | Luminal A | 11 | 12.0 | 4.8-19.1 |
| Luminal B/HER2− | 35 | 38.0 | 27.6-48.5 | |
| Luminal B/HER2+ | 16 | 17.4 | 9.1-25.7 | |
| HER2+ | 9 | 9.8 | 3.2-16.4 | |
| Triple negative | 21 | 22.8 | 13.7-31.9 | |
| PRE-NAC AXILLARY STATUS | Positive | 76 | 82.6 | 74.3-90.9 |
| Negative | 16 | 17.4 | 9.1-25.7 |
CI = confidence interval; NA = not available; SD = standard deviation
Table 2
MRI diagnostic performance in predicting pathologic response
| Pathology | Total | |||
|---|---|---|---|---|
| No pCR | pCR | |||
| MRI | No iCR | TP = 48 | FP = 6 | 54 (58.70%) |
| iCR | FN = 16 | TN = 22 | 38 (41.30%) | |
| Total | 64 (69.60%) | 28 (30.40%) | 92 (100%) | |
FN = false negative; FP = false positive; iCR = imaging complete response; pCR = pathologic complete response; TN = true negative; TP = true positive
Figure 1.
Dispersion graph of the correlation between residual tumour sizes (cm) calculated at preoperative MRI (on the X-axis) and at pathological examination (on the Y-axis). Each point represents a tumour; if the pairs of data coincide, the points overlap. The bisector corresponds to the equivalence line. On the graph, the closer the points are to the equivalence line, the greater the correlation between MRI and pathology.
Table 3
Factors affecting the MRI diagnostic accuracy based on the discrepancy between MRI and pathologic residual tumour size
| Variable | No. | Discrepancy (mean ± SD) | p-value |
|---|---|---|---|
| Age (years) | |||
| ≤45 | 43 | 1.09±1.14 | 0.281 |
| > 45 | 46 | 0.84 ±1.01 | |
| Baseline tumour size (cm) | |||
| ≤5 | 74 | 0.85 ±0.99 | 0.050 |
| >5 | 15 | 1.53 ±1.33 | |
| Histological type | 0.818 | ||
| ductal | 83 | 0.97 ±1.09 | |
| lobular | 6 | 0.87 ±0.82 | |
| Histological grade | <0.001 | ||
| 1 or 2 | 40 | 1.44 ±1.24 | |
| 3 | 47 | 0.56 ±0.71 | |
| Hormonal receptor status | 0.033 | ||
| positive | 59 | 1.14 ±1.13 | |
| negative | 30 | 0.63 ±0.87 | |
| HER2 status | 0.906 | ||
| positive | 24 | 0.99 ±1.12 | |
| negative | 65 | 0.96 ±1.07 | |
| Molecular subtype | 0.055 | ||
| Luminal A | 10 | 1.59 ±1.34 | |
| Luminal B-HER2− | 34 | 1.05 ±1.06 | |
| Luminal B-HER2+ | 15 | 1.02 ±1.14 | |
| HER2+ | 9 | 0.92 ±1.14 | |
| Triple negative | 21 | 0.50 ±0.70 | |
SD = standard deviation
Table 4
Results from the Multivariate Regression Analysis
| Variable | Regression coefficient (B) | se | p | 95% CI |
| Tumour grade | 0.807 | 0.236 | 0.001 | 0.338-1.276 |
| HR status | 0.086 | 0.249 | 0.729 | −0.408-0.581 |
| BTS (MRI) | 0.610 | 0.277 | 0.030 | 0.060-1.161 |
BTS = baseline tumour size; CI = confidence interval; se = standard error
Figure 2.
Discrepancy between MRI-measured and pathologic residual tumour size, based on molecular subtypes.