Table 1. Summary of patient demographics, tumour characteristics and local recurrence rates in relation to excised margin width.
| Variable | Total number (N) | |||
| Studies | Women | |||
| Total no. of patients (N) | 31 | 40 265 | ||
| Absolute number | ||||
| Study design | Studies (n) | Womenn (%) | ||
| Retrospective | 24 | 38 095 (94.6) | ||
| Prospective | 7 | 2170 (5.4) | ||
| Age in years, median (IQR) | 55.5 (53.1–57.8) | 22 | 37 023 (91.9) | |
| Follow-up in months, median (IQR) | 86.4 (69.2–100.2) | 28 | 37 807 (93.9) | |
| Tumour size in cm, median (IQR) | 1.48 (0.82–2.0) | 9 | 3272 (8.1) | |
| Therapy | ||||
| Whole breast radiotherapy | ||||
| Yes | 31 | 40 265 (100) | ||
| No | 0 | 0 (0) | ||
| Boost radiotherapy | ||||
| Yes | 18 | 4620 (59.1) | ||
| No | 20 | 3251 (39.3) | ||
| Unknown | 11 | 31 984 (100) | ||
| Hormone therapy | ||||
| Yes | 13 | 8395 (27.3) | ||
| No | 15 | 21 340 (71.8) | ||
| Unknown | 16 | 10 530 (35.4) | ||
| Receptor status | ||||
| ER positive | 9 | 1983 (56.2) | ||
| ER unknown | 22 | 36 446 (100) | ||
| PR positive | 5 | 1013 (46.7) | ||
| PR unknown | 26 | 38 095 (100) | ||
| Surgery | ||||
| BCS | 31 | 40 265 (100) | ||
| Number of re-excision | ||||
| Re-excision was BCS | 8 | 1214 (26.4) | ||
| Re-excision was mastectomy | 3 | 39 (4.4) | ||
| DCIS grade | ||||
| Low nuclear grade | 15 | 987 (9.3) | ||
| Intermediate nuclear grade | 15 | 3021 (28.4) | ||
| High nuclear grade | 16 | 6698 (54.8) | ||
| Unknown | 8 | 458 (5.0) | ||
| Margin width(as defined by each study) | ||||
| Negative | All negative | 24 | 7412 (48.9) | |
| Negative unknown distance | 2 | 68 (15.0) | ||
| Negative >1 mm | 2 | 1237 (78.9) | ||
| Negative >2 mm | 11 | 2824 (65.8) | ||
| Close | ||||
| Close 0.1–1 mm | 11 | 657 (7.9) | ||
| Close 0.1–2 mm | 12 | 2094 (18.3) | ||
| >0.1 and <10 mm | 11 | 3853 (42.8) | ||
| Positive (tumour on ink/0 mm) | 12 | 456 (4.4) | ||
| Unknown | 8 | 565 (11.6) | ||
| Total number of local recurrence | 27 | 1468 (4.4) | ||
| Type of local recurrence | ||||
| DCIS | 19 | 638 (2.0) | ||
| Invasive | 19 | 738 (2.3) | ||
| Not stated | 4 | 7013 (100) | ||
| Unknown | 5 | 69 (6.8) | ||
| Both | 3 | 23 (1.3) | ||
| Local recurrence per margin width comparison(smaller vs larger) | Absolute risk n/N (%) | Absolute risk reduction % | ||
| Smaller | Larger | |||
| 0 mm vs >0 mm | 25/208 (12.0) | 103/1707 (6.0) | 6 | |
| 0 mm vs 0.1–2 mm | 17/254 (6.7) | 45/988 (4.6) | 2.1 | |
| 0 mm vs >2 mm | 20/264 (7.6) | 121/5114 (2.4) | 5.2 | |
| 0.1–1 mm vs >1 mm | 15/68 (22.1) | 7/98 (7.1) | 14.9 | |
| 0.1–2 mm vs >2 mm | 127/1586 (11.1) | 279/6537 (7.6) | 3.7 | |
Margins are defined as follows: positive (tumour on ink or 0 mm), negative (there is no disease within a predefined agreed margin width) and close (no disease on ink but the defined negative margin clearance has not been achieved).
n is the subgroup patient number.
N is the total patient number.
BCSbreast-conserving surgeryDCISductal carcinoma in situERoestrogen receptorPRprogesterone receptor