Table 1.
Tumor and surgical characteristics of 423 cases with breast cancer with clear or positive resection margins after BCS in two hospitals
| Variable | Total cases (n = 423) | Cases with positive margins (n = 34, 8%) | Cases with clear margins (n = 389, 92%) | p value |
|---|---|---|---|---|
| Age at time of surgery, median (IQR), years | 58 (51–66) | 60 (50–69) | 58 (51–65) | 0.21 |
| BMI, mean±SD, kg/m2 | 25±4.0 | 25.2±4.8 | 25±3.9 | 0.74 |
| Smoker, yes, n (%) | 57 (13.5) | 5 (14.7) | 52 (13.4) | 0.83 |
| Cup size, n (%) | 0.56 | |||
| A–B | 123 (29.1) | 8 (23.5) | 115 (29.6) | |
| C–D | 207 (49) | 20 (58.8) | 187 (48.1) | |
| E–I | 83 (19.6) | 6 (17.6) | 77 (19.8) | |
| Missing | 10 (2.3) | 0 (0.0) | 10 (2.5) | |
| Tumor localization, n (%) | 0.60 | |||
| Upper inner quadrant | 67 (15.8) | 2 (5.9) | 65 (16.7) | |
| Lower inner quadrant | 44 (10.4) | 5 (14.7) | 39 (10.0) | |
| Upper outer quadrant | 185 (43.7) | 15 (44.1) | 170 (43.7) | |
| Lower outer quadrant | 72 (17.0) | 6 (17.6) | 66 (17.0) | |
| Central | 44 (10.4) | 5 (14.7) | 39 (10.0) | |
| Overlapping | 11 (2.6) | 1 (2.9) | 10 (2.6) | |
| Histological finding, n (%) | 0.00 | |||
| DCIS | 69 (16.3) | 5 (14.7) | 64 (16.5) | |
| IDC | 227 (53.7) | 13 (38.2) | 214 (55.0) | |
| IDLC | 68 (15.7) | 5 (14.7) | 63 (16.2) | |
| ILC | 34 (8.0) | 11 (32.4) | 23 (5.9) | |
| Othera | 25 (5.9) | 0 (0.0) | 25 (6.4) | |
| cT categoryb, n (%) | 0.01 | |||
| 1a–c | 224 (53) | 12 (35.3) | 212 (54.5) | |
| 2 | 118 (27.9) | 14 (41.2) | 104 (26.7) | |
| 3–4 | 7 (1.6) | 3 (8.8) | 4 (1.0) | |
| is | 74 (17.5) | 5 (14.7) | 69 (17.7) | |
| cN status, n (%) | 0.20 | |||
| Positive | 37 (8.7) | 5 (14.7) | 32 (8.2) | |
| Negative | 386 (91.3) | 29 (85.3) | 357 (91.8) | |
| Neo-adjuvant therapy, n (%) | 109 (25.8) | 11 (32.4) | 98 (25.2) | 0.36 |
| MRI before surgery, n (%) | 305 (72.1) | 28 (82.4) | 277 (71.2) | 0.32 |
| Maximal radiological diameter of disease, median (IQR), mm | 15.5 (9–23) | 19.5 (7–40) | 15 (9–23) | 0.01 |
| Radiological underestimation of tumor size, median (IQR), mm | 5 (2–12) | 12 (6–24) | 4 (2–11) | 0.00 |
| Maximal pathological lumpectomy diameter, median (IQR), mm | 55 (45–70) | 60 (49–73) | 55 (45–70) | 0.55 |
| Postoperative maximal pathological tumor size, median (IQR), mm | 16 (9–25) | 25 (18–45) | 15 (9–24) | 0.00 |
| Presence of DCIS component in resection, n (%) | 261 (61.7) | 22 (64.7) | 239 (61.4) | 0.73 |
| Hospital, n (%) | 0.00 | |||
| High-volume | 322 (76.1) | 19 (55.8) | 303 (77.9) | |
| Low-volume | 101 (23.9) | 15 (44.2) | 86 (22.1) |
Chi-square test was used to compare categorical covariates between cases with clear and positive resection margins after BCS.
BCS, breast-conserving surgery; IQR, interquartile range; BMI, body mass index; SD, standard deviation; IDC, invasive ductal carcinoma; IDLC, invasive ductolobular carcinoma; ILC, invasive lobular carcinoma; DCIS, ductal carcinoma in situ; cT, clinical primary tumor size; cN, clinical lymph node status; MRI, magnetic resonance imaging; is, in situ.
aLobular carcinoma in situ, mucinous carcinoma, metaplastic carcinoma, papillary carcinoma and tubular carcinoma.
bTNM classification following the American Joint Committee on Cancer Eighth Edition Cancer Staging.