Table 1.
Patients and tumors characteristics by location of aromatase protein expression status at baseline
| Characteristics | Aromatase protein expression [n (%)]b | |||
|---|---|---|---|---|
| Tumor epithelial aromatase | Stromal aromatase | |||
| Negative | Positive | Negative | Positive | |
| Treatment | ||||
| Tamoxifen | 24 (53%) | 72 (49%) | 29 (54) | 63 (48) |
| Letrozole | 21 (47%) | 75 (51%) | 25 (46) | 69 (52) |
| P-value | 0.6102 | 0.4605 | ||
| Age (year) | 66.8 | 67.6 | 67.6 | 67 |
| P-valuec | 0.6214 | 0.6969 | ||
| Clinical tumor size (cm) | 5.7 | 4.8 | 5.5 | 4.7 |
| P-valuec | 0.0144 | 0.0398 | ||
| Pre treatment grade | ||||
| I | 4 (10%) | 16 (13%) | 4 (8%) | 16 (15%) |
| II/III | 38 (90%) | 103 (87%) | 47 (92%) | 90 (85%) |
| P-value | 0.5971 | 0.3064 | ||
| Pathological tumor size | ||||
| ≤20 mm | 11 (27%) | 44 (32%) | 11 (27%) | 44 (32%) |
| >20 mm | 30 (73%) | 95 (68%) | 30 (73%) | 95 (68%) |
| P-value | 0.5567 | 0.5567 | ||
| Pathological node status | ||||
| Negative | 16 (41%) | 55 (43%) | 21 (47%) | 50 (43%) |
| Positive | 23 (59%) | 72 (57%) | 24 (53%) | 65 (57%) |
| P-value | 0.8017 | 0.7160 | ||
| HER2 statusa | ||||
| Negative | 40 (91%) | 140 (95%) | 50 (93%) | 125 (95%) |
| Positive | 4 (9%) | 7 (5%) | 4 (7%) | 6 (5%) |
| P-value | 0.2806 | 0.4810 | ||
| ER statusc | ||||
| Negative | 11 (20%) | 12 (8%) | 14 (20%) | 9 (6%) |
| Positive | 44 (80%) | 148 (93%) | 55 (80%) | 131 (94%) |
| P-value | 0.0098 | 0.0027 | ||
| PgR statusc | ||||
| Negative | 16 (36%) | 48 (33%) | 20 (37%) | 43 (33%) |
| Positive | 28 (64%) | 98 (67%) | 34 (63%) | 87 (67%) |
| P-value | 0.6688 | 0.6072 | ||
aHER2 IHC with fluorescence in situ hybridization confirmation and IHC for ER and PgR were performed as previously described [12]
bAromatase protein expression considered positive if any aromatase IHC staining was present
cFor age and clinical tumor size the student’s t test was used to compare the aromatase positive and negative groups. For binary variables the X2 test was applied with Fisher’s exact test if a count in any cell was less than 5