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Practice Uncertainties

Does the addition of mesh improve outcomes in implant based breast reconstruction after mastectomy for breast cancer?

BMJ 2018; 362 doi: https://doi.org/10.1136/bmj.k2607 (Published 06 July 2018) Cite this as: BMJ 2018;362:k2607

Response to Re: Does the addition of mesh improve outcomes in implant based breast reconstruction after mastectomy for breast cancer?

Potter and colleagues provide a sobering reflection on the accuracy and legitimacy of information giving and informed consent in the context of IBBR with mesh - be this synthetic or biological.1 There is poor or non-existent documentation of patient reported quality of life outcomes (PRO QoL) for all types of reconstruction.2 Several collaborative initiatives such as the Systemic Evaluation of Patient Reported Outcome Protocol Content (EPiC) are proposed or ongoing for UK clinical trials.3 The CONSORT-PRO extension has also highlighted poor methodological reporting for PROs in randomized trials.3 Prospective collection and reporting of all baseline (pre-operative) PRO data is implicit with both MROC and other cohort studies showing this to be a significant co-variate on multivariate regression analysis.3-5 When using QoL as a primary outcome measure, relevant power calculations must be based on necessarily small effect sizes for QoL domains using validated questionnaires such as BREAST-Q and the EORTC QLQ-BRECON23.4,5 This evaluation of QoL as primary or secondary outcome measures requires a large number of patients (up to 1000 per arm) to test for non-inferiority (or equivalence). Population based norms for the BREAST-Q facilitate interpretation of clinically meaningful changes in QoL scores over time.4 Determination of minimally clinically important differences (MIDs) for each QoL domain are a particular challenge and have yet to be defined for either of the aforementioned questionnaires.4,5

NICE recommends that breast reconstruction be offered to all eligible women undergoing mastectomy, but arguably this does not take adequate account of the need for post-mastectomy radiotherapy (PMRT) with its implications for increased surgery comlications.6,7 Indications for the latter have broadened in recent years with up to one-third of mastectomy patients receiving PMRT.6 Recent data from the Michigan Breast Reconstruction Outcomes Consortium (MROC) have confirmed a significant increase in major complications following implant based breast reconstruction (IBBR) at 1 and 2 years amongst the irradiated group of 622 patients (38% of 2247 patients) [p<0.0001].7 Radiotherapy adversely affects all types of breast reconstruction although autologous tissue-based methods are generally more tolerant of PMRT.6, Perhaps ironically, there has been an escalation of IBBR since the advent of mesh-assisted implant reconstructions despite more widespread employment of PMRT.8 Consequently, multidisciplinary teams should exercise discretion when offering reconstruction to women who are likely to receive radiation. Pre-reconstruction sentinel node biopsy may aid selection of patients for PMRT and facilitate decision-making for one- versus two stage reconstruction or immediate versus delayed autologous procedures.9

There are no randomized trials testifying to the cost-effectiveness of mesh-based IBBR and radiation with one systematic review reporting an increase of 2 - 3 fold in surgical complications for irradiated patients.10 Despite this lack of evidence, many surgeons proceed with IBBR using a mesh when PMRT is recommended (based on 1 - 3 positive axillary nodes or a PMRT index exceeding a threshold value).7-9

Decision-making for implant location (pre-pectoral or sub-pectoral) together with the extent of mesh coverage (sling or total wrap) is determined by technical factors and individual patient characteristics.11,12 Digital mammography has been used pre-operatively to ascertain whether an implant can be safely be placed subcutaneously with a skin coverage thickness of at least 1.90 to 2.0cm (breast tissue coverage classification (BTCC)).12 Some advocate formal assessment of skin perfusion using an objective tool such as fluorescence (I-SPY), especially for pre-pectoral approaches and decision-making for two-stage IBBR.11 Furthermore, achievement of a “hand in glove” breast reconstruction with minimal redundant skin envelope relative to mesh-assisted implant volume will minimize dead space and seroma formation.11 Larger breasted women may benefit from a skin-reducing mastectomy with a dermal flap in conjunction with a mesh sling or total wrap.11

These different technical options result in a range of surgical variables that require flexible and individualized pragmatic decision-making. Prioritizing these to optimize clinical practice is a major challenge over the forthcoming years and attempts to standardize techniques should underpin any future trials.

References:
1. Potter S, MacKenzie M, Blazeby JM. Does the addition of mesh improve outcomes in implant based breast reconstruction after mastectomy for breast cancer? BMJ (2018); 362:36-38.
2. Winters ZE, Benson JR, Pusic AL. A systematic review of the clinical evidence to guide treatment recommendations in breast reconstruction based on patient reported outcome measures and health related quality of life. Annals of Surgery (2010); 252(6): 929-942.
3. Ahmed K, Kyte D, Keeley T et al. Systematic evaluation of patient reported outcome (PRO) protocol content and reporting in UK cancer clinical trials: the EPiC protocol. BMJ Open (2016); 6: 1-5.
4. Mundy LR, Homa K, Klassen AF et al. Breast Cancer and Reconstruction: Normative Data for Interpreting the BREAST-Q. PRS (2017); 139(5): 1046-1055.
5. Winters ZE, Afzal M, Rutherford C, et al. International validation of the European Organisation of the Research and Treatment of Cancer QLQ-BRECON23quality of life questionnaire foe women undergoing breast reconstruction. British Journal of Surgery (2018); 105(3): 209-222.
6. Sekiguchi K. Controversies in the role of post-mastectomy radiotherapy in breast cancer patients with one to three positive axillary nodes and safety of integrating radiotherapy and breast reconstruction. Breast Cancer (2017); 24: 493-495.
7. Jagsi R, Momoh AO, Qi J, et al. Impact of radiotherapy complications and patient-reported outcomes after breast reconstruction. Journal of National Cancer Institute (2018); 110(2): 1-9.
8. Jagsi R, Jiang J, Momoh AO, et al. Trends and Variation in Use of Breast Reconstruction in Patients with Breast Cancer Undergoing Mastectomy in the United States. Journal of Clinical Oncology (2014); 32(9): 919-925.
9. Wilkins EG, Hamill JB, Kim HM et al. Complications in Post-mastectomy Breast Reconstruction: One-year Outcomes of the Mastectomy Reconstruction Outcomes Consortium (MROC) Study. Annals of Surgery (2018); 267(1): 164-170.
10. Valdatta L, Cattaneo AG, Pellegatta I et al. Acellular dermal matrices and radiotherapy in breast reconstruction: a systematic review and meta-analyses of the literature. Plastic Surgery International (2014); ID 472604; 1-10.
11. Chatterjee A, Nahabedian MY, Gabriel A et al. Early assessment of post-surgical outcomes with pre-pectoral breast reconstruction: a literature review and meta-analysis. J Surgical Oncology (2018); 117(6): 1119-1130.
12. Rancati A, Angrigiani C, Hammond D, et al. Pre-operative digital mammography imaging in conservative mastectomy and immediate reconstruction. Gland Surgery 2016; 5(1): 9-14.

Competing interests: No competing interests

12 July 2018
Zoe E Winters
Consultant Oncoplastic Breast Surgeon and Honorary Professor of Breast Surgery
Professor John R. Benson, Cambridge University Hospital NHS Trust and Anglia Ruskin University, Cambridge
Surgery and Interventional Trials Unit, Division of Surgery and interventional Science, University College London
Charles Bell House, 43-45 Foley Street, Fitzrovia, London, W1W 7JN