Key Points
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Question Does oncoplastic breast conservation (OBC) with large resection volumes (OBCII; Clough level II/Tübingen 5-6) achieve better local recurrence rates than conventional breast conserving surgery (BCS) or low volume oncoplastic procedures (OBCI; Clough level I/Tübingen 3-4)?
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Findings Of 3,177 women, 30% were treated with OBC. The BCS/OBCI group had significantly smaller resection margins and higher re-excision rates. At a median follow-up of 74.5 months, however, there were no differences in recurrence or survival rates between the two groups.
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Meaning OBCII allows for resection of larger tumors without increasing local recurrence risk and reduces the re-excision rate. Margins larger than “no ink on tumor” do not improve local control.
Materials and Methods
Design
Inclusion Criteria
Exclusion Criteria
Surgical Groups
Oncologic Endpoints
Perioperative Endpoint
Statistical Analysis
Results
Participating Breast Centers
Clinicopathological Characteristics
BCS/OBCI | OBCII | p value | |||
---|---|---|---|---|---|
n | % | n | % | ||
Entire cohort | 2880 | 91 | 297 | 9 | |
Age (yr) | 2879 | 58 [49-68] | 297 | 54 [46-63] | <0.001 |
Invasive cancer | 2673 | 93 | 260 | 88 | 0.0012 |
Lobular histology | 189 | 7 | 21 | 7 | 0.7372 |
NAC | 441 | 16 | 65 | 25 | 0.0032 |
Tumor size (mm)* | 379 | 30 [23-40] | 41 | 30 [23-43] | 0.4515 |
cT1/2* | 363 | 86 | 34 | 77 | 0.1099 |
Radiotherapy | 2652 | 92 | 293 | 98 | <0.001 |
Radiotherapy boost | 2033 | 70 | 197 | 66 | 0.1264 |
Endocrine therapy | 1927 | 67 | 196 | 66 | 0.7494 |
Chemotherapy | 1752 | 61 | 186 | 63 | 0.5464 |
BCS/OBCI | OBCII | p value | |||
---|---|---|---|---|---|
n | % | n | % | ||
Entire cohort | 2880 | 91 | 297 | 9 | |
Pathological T stage | |||||
pTis | 231 | 8 | 34 | 12 | <0.001 |
pT1 | 1367 | 50 | 103 | 38 | |
pT2 | 1014 | 37 | 119 | 43 | |
pT3/4 | 106 | 4 | 18 | 7 | |
Pathological N stage | |||||
pN0 | 1357 | 49 | 103 | 37 | <0.001 |
pN1 | 1173 | 42 | 163 | 58 | |
pN2/3 | 241 | 9 | 16 | 6 | |
Subtype | |||||
Luminal A | 272 | 10 | 18 | 6 | <0.001 |
Luminal B | 1209 | 43 | 104 | 36 | |
Luminal HER2+ | 505 | 18 | 80 | 27 | |
non-luminal HER2+ | 232 | 8 | 40 | 14 | |
Triple negative | 611 | 22 | 50 | 17 |
Surgical Outcomes
Oncological Outcomes
n (%)* | Cause-specific hazard | Subdistribution hazard | |||
---|---|---|---|---|---|
Univariate model | Multivariable model** | Univariate model | Multivariable model** | ||
LBCR | 2834 (97) | 1.23 (0.67, 2.07), p = 0.470 | 1.33 (0.67, 2.39), p = 0.380 | 1.26 (0.89, 1.78), p = 0.194 | 1.40 (0.96, 2.05), p = 0.080 |
RBCR | 3175 (72) | 0.989 (0.41, 2.01), p = 0.978 | 0.731 (0.27, 1.59), p = 0.473 | (0.62, 1.66), p = 0.473 | 0.78 (0.48, 1.27), p = 0.33 |
DDFS | 2872 (253) | 1.00 (0.58, 1.37), p = 0.699 | 0.84 (0.52, 1.31), p = 0.441 | 0.92 (0.61, 1.39), p = 0.710 | 0.84 (0.56, 1.27), p = 0.429 |
LBCR*** | 2561 (78) | 1.19 (0.53, 2.66), p = 0.677*** | 1.25 (0.83, 1.87), p = 0.292*** |