Summary of findings 3. Any O‐BCS compared to mastectomy plus reconstruction for women with primary breast cancer.
| Any O‐BCS compared to mastectomy plus reconstruction for women with primary breast cancer | ||||||
| Patient or population: women with primary breast cancer Setting: mixed multicentre/single‐centre studies with initial inpatient procedure and outpatient follow‐up Intervention: any O‐BCS Comparison: mastectomy plus reconstruction (Mx+R) | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with Mx+R | Risk with any O‐BCS | |||||
| Local recurrence‐free survival | Study population | HR 1.37 (0.72 to 2.62) | 3785 (1 observational study) | ⊕⊝⊝⊝ Very lowa,b | Any O‐BCS may result in little to no difference in local recurrence‐free survival compared to Mx+R. Estimates of risk with BCS were calculated using an average of non‐adjusted baseline control rates from included studies. Also calculated HR for LRR (local recurrence rates) for studies with a comparison of Mx+/‐R where the vast majority were reconstructed; HR 1.59 (0.71 to 3.55) | |
| 43 per 1000 | 58 per 1000 (31 to 108) | |||||
| Cumulative local recurrence rate | 0 studies | Re‐excisions are not often needed for mastectomy, therefore this outcome is not relevant for this comparison and therefore not studied. | ||||
| Disease‐free survival | Study population | HR 0.45 (0.09 to 2.22) | 317 (1 observational study) | ⊕⊝⊝⊝ Very lowa,c | Estimates of risk with BCS were calculated using an average of non‐adjusted baseline control rates from included studies. Also calculated HR for DFS for studies with a comparison of Mx+/‐R where the vast majority were reconstructed; HR 1.03 (0.75 to 1.42) | |
| 189 per 1000 | 90 per 1000 (19 to 371) | |||||
| Re‐excision rates | 0 studies | ‐ | Re‐excisions are not often needed for mastectomy, therefore this outcome is not relevant for this comparison. | |||
| Complications | Study population | RR 0.49 (0.45 to 0.54) | 4973 (5 observational studies) | ⊕⊝⊝⊝ Very lowa,d | ||
| 492 per 1000 | 241 per 1000 (221 to 266) | |||||
| Recall rates | 0 studies | ‐ | Recall biopsy is not often needed for mastectomy, therefore this outcome is not relevant for this comparison. | |||
| Patient‐reported outcome measures | The evidence is too methodologically diverse and of high risk of bias due to measurement of outcomes to combine | ‐ | (3 observational studies) | ‐ | There is insufficient evidence to make a conclusion | |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). BCS: breast‐conserving surgery; CI: confidence interval; DFS: disease‐free survival; HR: hazard ratio;Mx: mastectomy; Mx+R: mastectomy with reconstruction; Mx+/‐R: mastectomy with or without reconstruction; O‐BCS: oncoplastic breast‐conserving surgery; RR: risk ratio. | ||||||
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GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
aDowngraded by two levels due to study limitation: serious risk of bias due to confounding. bDowngraded by one level due to imprecision: optimal size not met. cDowngraded by one level due to imprecision: 95% CI overlaps no effect. dDowngraded by two levels due to heterogeneity: I2 = 85%, P < 0.001.