Table 1 Participants’ clinical characteristics
| Characteristic | With ovarian function (n = 34) | Without ovarian function (n = 56) | P value |
|---|---|---|---|
| Age [% (years)] | 0.002 | ||
| ≥40 (n = 67) | 19 (28.4) | 48 (71.6) | |
| <40 (n = 23) | 15 (65.2) | 8 (34.8) | |
| BMI (kg/m2, mean ± SD) | 0.136 | ||
| <24 (n = 65) | 21 (32.3) | 44 (67.7) | |
| 24–28 (n = 20) | 12 (60.0) | 8 (40.0) | |
| ≥28 (n = 5) | 1 (20) | 4 (80) | |
| Menarche age (years, mean ± SD) | 13.6 ± 1.5 | 13.8 ± 1.5 | 0.692 |
| No. of pregnancies (mean ± SD) | 2.7 ± 1.5 | 2.8 ± 1.4 | 0.918 |
| No. of births (mean ± SD) | 1.1 ± 0.3 | 1.2 ± 0.6 | 0.414 |
| Pathological classification (%) | 0.450 | ||
| Ductal carcinoma (n = 82) | 31 (37.8) | 51 (62.2) | |
| Adenocarcinoma (n = 2) | 0 (0) | 2 (100.0) | |
| Lobular carcinoma (n = 6) | 3 (50.0) | 3 (50.0) | |
| Histological classification (%) | 0.160 | ||
| 1 (n = 2) | 0 (0) | 2 (100.0) | |
| 2 (n = 35) | 11 (31.4) | 24 (68.6) | |
| 3 (n = 53) | 23 (43.4) | 30 (56.6) | |
| Tumor size | 0.013 | ||
| T1 (n = 28) | 15 (53.6) | 13 (46.4) | |
| T2 (n = 52) | 18 (34.6) | 34 (56.4) | |
| T3 (n = 10) | 1 (10.0) | 9 (90.0) | |
| Lymph node stage | 0.023 | ||
| N0 (n = 20) | 9 (45.0) | 11 (55.0) | |
| N1 (n = 26) | 15 (57.7) | 11 (42.3) | |
| N2 (n = 18) | 4 (22.2) | 14 (77.8) | |
| N3 (n = 26) | 6 (23.1) | 20 (76.9) | |
| ER status | 0.839 | ||
| ER+ (n = 84) | 31 (36.9) | 53 (63.1) | |
| ER− (n = 6) | 3 (50.0) | 3 (50.0) | |
| PR status | 1.000 | ||
| PR+ (n = 78) | 29 (37.2) | 49 (62.8) | |
| PR− (n = 12) | 5 (41.7) | 7 (58.3) | |
| HER-2 score (%) | 0.515 | ||
| 0 (n = 59) | 21 (35.6) | 38 (64.4) | |
| 1 (n = 10) | 5 (50.0) | 5 (50.0) | |
| 2 (n = 13) | 3 (23.1) | 10 (76.9) | |
| 3 (n = 8) | 5 (62.5) | 3 (37.5) | |
| Targeted therapy (%) | 3 (33.3) | 6 (66.7) | 1.000 |
| Chemotherapy regimens (%) | 0.734 | ||
| Taxanes (n = 1) | 0 (0) | 1 (100.0) | |
| Anthracycline or cyclophosphamide (n = 31) | 12 (38.7) | 19 (61.3) | |
| Both anthracycline and cyclophosphamide (n = 58) | 22 (37.9) | 36 (62.1) | |
| Chemotherapy cycle (mean ± SD) | 6.5 ± 1.2 | 6.5 ± 1.3 | 0.676 |
| Duration of tamoxifen (month, mean ± SD) | 14.0 ± 13.0 | 9.9 ± 12.6 | 0.035 |
| Duration between completing chemotherapy and ovariectomy (month, mean ± SD) | 14.7 ± 12.7 | 10.7 ± 12.2 | 0.046 |
| Ovarian cyst (%) | 15 (44.1) | 6 (10.7) | <0.001 |
| Metastatic tumor of breast cancer (n = 1) | 1 (100) | 0 (0) | |
| Benign epithelial tumor (n = 10) | 4 (40) | 6 (60) | |
| Functional cysts (n = 10) | 10 (100) | 0 (0) | |
|
FSH (IU/L, mean ± SD) | 26.0 ± 2.0 | 45.2 ± 23.9 | <0.001 |
|
LH (IU/L, mean ± SD) | 15.2 ± 10.2 | 24.2 ± 12.1 | <0.001 |
|
E2 (pg/ml, mean ± SD) | 156.3 ± 311.7 | 19.6 ± 57.4 | 0.002 |