Table 1.
Patient and study characteristics
| N Included | |||||
|---|---|---|---|---|---|
| Variable | Studies | Patients | Median | Interquartile Range (IQR) | (Range) |
| N patients (total)a | 20 | 8651 | 226 | 108-439 | (50-2996) |
| N with known margin status | 7883 | 210 | 98-422 | (50-2788) | |
| Recruitment timeframe (year) | 20 | 8651 | - | - | - |
| Start | 8651 | 1984 | 1977-1988 | (1968-2003) | |
| End | 8651 | 2001 | 1995-2007 | (1990-2010) | |
| Mid-interval | 8651 | 1991 | 1987-1996 | (1979-2006) | |
| Age (years; median or mean) | 20 | 8651 | 53.7 | 53.0-56.7 | (43.0-62.1) |
| Follow-up (months; median or mean) | 20 | 8651 | 78.3 | 59.0-94.7 | (51.5-126.0) |
| Prevalence of LR (patients with known margin status) | 20 | 7883 | 8.3% | 5.0-11.9% | (2.2-24.0%) |
| Total number of LR | 865 | - | - | - | |
| Type of LR | 17 | 952 | - | - | - |
| DCIS | 479 | 50.0% | 42.9-57.1% | (0.0-75.0%) | |
| Invasive | 458 | 50.0% | 41.7- 56.5% | (25.0-100.0%) | |
| Unknown | 15 | 0.0% | 0.0-0.0% | (0.0-7.1%) | |
| WBRT | 20 | 8920 | - | - | - |
| Yesb | 6353 | 100.0% | 50.3-100.0% | (0.0-100.0%) | |
| No | 2533 | 0.0% | 0.0-53.4% | (0.0-100.0%) | |
| Unknown | 34 | 0.0% | 0.0-0.0% | (0.0-1.1%) | |
| WBRT dose (Gy, median) | 11 | 3990 | 50.0 | 50.0-50.0 | (42.5-50.0) |
| Radiation boost | 19 | 5925 | - | - | - |
| Yes | 3207 | 70.9% | 28.4-95.5% | (0.0-100.0%) | |
| No | 2715 | 29.1% | 4.5-71.6% | (0.0-100.0%) | |
| Unknown | 3 | 0.0% | 0.0-0.0% | (0.0-0.6%) | |
| Boost dose (Gy, median) | 8 | 2734 | 10.0 | 10.0-10.0 | (10.0-10.8) |
| Total dose (Gy, median) | 12 | 3890 | 60.0 | 60.0-60.4 | (50.0-64.0) |
| Endocrine therapy | 19 | 8392 | - | - | - |
| Yesd | 1563 | 20.8% | 0.0-31.4% | (0.0-83.2%) | |
| No | 6722 | 79.2% | 68.6-100.0% | (16.8-100.0%) | |
| Unknown | 107 | 0.0% | 0.0-0.0% | (0.0-13.6%) | |
| Screen detected | 14 | 7661 | - | - | - |
| Yes | 6520 | 85.8% | 71.6-89.9% | (45.6-100.0%) | |
| No | 1106 | 14.2% | 10.1-27.2% | (0.0 - 54.4%) | |
| Unknown | 35 | 0.0% | 0.0-0.1% | (0.0-2.8%) | |
| Comedonecrosis | 14 | 6465 | - | - | - |
| Present | 3085 | 37.5% | 27.1-46.0% | (10.4-60.1%) | |
| Absent | 2713 | 55.5% | 34.3-61.5% | (2.0-81.6%) | |
| Unknown | 667 | 5.3% | 0.0-15.9% | (0.0-61.1%) | |
| Grade | 16 | 7225 | - | - | - |
| I-II | 4033 | 57.3% | 37.0-65.5% | (7.3-92.5%) | |
| I c | 901 | 17.5% | 9.1-25.2% | (1.8-64.5%) | |
| II c | 1163 | 28.0% | 23.6-34.9% | (5.5-45.0%) | |
| III | 2243 | 28.4% | 17.9-35.4% | (3.5-45.6%) | |
| Unknown | 949 | 9.2% | 0.0-37.3% | (0.0-87.3%) | |
| Hormone receptor | 5 | 1479 | - | - | - |
| Positive | 740 | 50.4% | 43.7-70.9% | (23.0-80.4%) | |
| Negative | 142 | 8.7% | 7.3-9.7% | (2.8-14.3%) | |
| Unknown | 597 | 40.9% | 16.8-46.6% | (14.8-69.8%) | |
| ER receptor | 3 | 1023 | - | - | - |
| Positive | 522 | 46.8% | 14.9-70.7% | (14.9-70.7%) | |
| Negative | 117 | 12.3% | 3.1-14.3% | (3.1-14.3%) | |
| Unknown | 384 | 40.9% | 15.0-82.0% | (15.0-82.0%) | |
| Tumour size (mm) | 8 | 1880 | 10.9 | 8.0-14.9 | (8.0-20.5) |
| Multifocality | 2 | 286 | - | - | - |
| Present | 46 | 12.6% | 0.0-25.1% | (0.0-25.1%) | |
| Absent | 134 | 58.5% | 16.9-100.0% | (16.9-100.0%) | |
| Unknown | 106 | 29.0% | 0.0-58.0% | (0.0-58.0%) | |
Total number of patients included in margins analyses by eligible studies, including those with unknown margin status. Excludes 269 patients with unconfirmed DCIS from one study (Bijker et al., 2006); those patients did not contribute to the analysis of margins in that study, but were included in descriptive covariate information. Hence, patient numbers for covariates in this table may include those patients, and may sum to more than 8651.
Includes 194 patients with APBI from one study.
From subset of 13 studies reporting grade I and II separately.
Of 11 studies using endocrine therapy, 7 used tamoxifen, 1 used either tamoxifen or other, and 3 did not report the type of endocrine therapy.
Abbreviations: APBI = accelerated partial breast irradiation; DCIS = ductal carcinoma in situ; ER = estrogen receptor; Gy = gray; IQR = interquartile range; LR = local recurrence; mm = millimetres; WBRT = whole-breast radiotherapy.