Table 2.
Patient characteristics according to MDR in breast density cohort.
| TAM-Only (n=476) | TAM + OFS (n=468) | ||||||
|---|---|---|---|---|---|---|---|
| No. (%) | No. (%) | ||||||
| Characteristics | MDR-negative (n=370) | MDR-positive (n=106) | P | MDR-negative (n=379) | MDR-positive (n=89) | P | |
| Age at enrollment, years | |||||||
| <35 | 49 (13.2) | 11 (10.4) | 0.732 | 61 (16.1) | 10 (11.2) | 0.507 | |
| 35–39 | 103 (27.8) | 31 (29.2) | 100 (26.4) | 24 (27.0) | |||
| 40–45 | 218 (58.9) | 64 (60.4) | 218 (57.5) | 55 (61.8) | |||
| Lymph node status | 0.979 | 0.203 | |||||
| Negative | 174 (47.0) | 50 (47.2) | 176 (46.4) | 48 (53.9) | |||
| Positive | 196 (53.0) | 56 (52.8) | 203 (53.6) | 41 (46.1) | |||
| Tumor size, cm | 0.063 | 0.933 | |||||
| <2 | 195 (52.7) | 45 (42.5) | 185 (48.8) | 43 (48.3) | |||
| ≥2 | 175 (47.3) | 61 (57.5) | 194 (51.2) | 46 (51.7) | |||
| Tumor grade | 0.039 | 0.002 | |||||
| 1 | 43 (11.6) | 21 (19.8) | 54 (14.2) | 28 (31.5) | |||
| 2 | 197 (53.2) | 61 (57.5) | 190 (50.1) | 38 (42.7) | |||
| 3 | 96 (25.9) | 18 (17.0) | 94 (24.8) | 16 (18.0) | |||
| Unknown | 34 (9.2) | 6 (5.7) | 41 (10.8) | 7 (7.9) | |||
| HER2 status | 0.760 | 0.423 | |||||
| Negative | 212 (57.3) | 65 (61.3) | 223 (58.8) | 51 (57.3) | |||
| Positive | 58 (15.7) | 15 (14.2) | 57 (15.0) | 17 (19.1) | |||
| Unknown | 100 (27.0) | 26 (24.5) | 99 (26.1) | 21 (23.6) | |||
| Chemotherapy regimen | 0.737a | 0.292a | |||||
| Anthracycline plus cyclophosphamide | 118 (31.9) | 30 (28.3) | 128 (33.8) | 26 ( (29.2) | |||
| Anthracycline plus cyclophosphamide followed by taxane | 187 (50.5) | 52 (49.1) | 189 (49.9) | 43 (48.3) | |||
| Anthracycline plus taxane | 14 (3.8) | 6 (5.7) | 19 (5.0) | 3 (3.4) | |||
| Anthracycline plus cyclophosphamide and taxane | 6 (1.6) | 1 (0.9) | 1 (0.3) | 1 (1.1) | |||
| Fluorouracil, anthracycline, and cyclophosphamide | 34 (9.2) | 15 (14.2) | 33 (8.7) | 13 (14.6) | |||
| Other taxane-based regimens | 4 (1.1) | 1 (0.9) | 5 (1.3) | 1 (1.1) | |||
| Other nontaxane-based regimens | 4 (1.1) | 0 (0.0) | 2 (0.5) | 2 (2.3) | |||
| Unknown | 3 (0.8) | 1 (0.9) | 2 (0.5) | 0 (0.0) | |||
| Surgery | 0.266 | 0.482 | |||||
| Total mastectomy | 130 (35.1) | 45 (42.5) | 145 (38.3) | 30 (33.7) | |||
| Breast-conserving surgery | 225 (60.8) | 59 (55.7) | 219 (57.8) | 57 (64.0) | |||
| Unknown | 15 (4.1) | 2 (1.9) | 15 (4.0) | 2 (2.2) | |||
| Radiotherapy at time of enrollment | 0.049 | 0.420 | |||||
| Done | 228 (61.6) | 54 (50.9) | 218 (57.5) | 47 (52.8) | |||
| Not done | 142 (38.4) | 52 (49.1) | 161 (42.5) | 42 (47.2) | |||
a
P-values are obtained with Fisher’s exact test.
HER2, human epidermal growth factor receptor 2; MDR, mammographic breast density reduction; TAM + OFS, tamoxifen plus ovarian function suppression group; TAM-only, tamoxifen-only group.