Nipple- and areola-sparing mastectomy for the treatment of breast cancer

  • Protocol
  • Intervention

Authors

  • Bruna Salani,

    1. Instituto do Câncer do Estado de Sao Paulo (ICESP/FMUSP), Sao Paulo, Sao Paulo, Brazil
    2. Centro de Estudos de Medicina Baseada em Evidências e Avaliação Tecnológica em Saúde, Brazilian Cochrane Centre, São Paulo, Brazil
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  • Rachel Riera,

    Corresponding author
    1. Centro de Estudos de Medicina Baseada em Evidências e Avaliação Tecnológica em Saúde, Brazilian Cochrane Centre, São Paulo, Brazil
    • Rachel Riera, Brazilian Cochrane Centre, Centro de Estudos de Medicina Baseada em Evidências e Avaliação Tecnológica em Saúde, São Paulo, Brazil. rachelriera@hotmail.com.

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  • Jessica Barrett,

    1. Institute of Public Health, University Forvie Site, Medical Research Council (MRC) Biostatistics Unit, Cambridge, UK
    2. Strangeways Research Laboratory, Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, Cambridge, UK
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  • Álvaro N Atallah,

    1. Centro de Estudos de Medicina Baseada em Evidências e Avaliação Tecnológica em Saúde, Brazilian Cochrane Centre, São Paulo, Brazil
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  • Jose Luiz Barbosa Bevilacqua

    1. Hospital Sirio Libanes, Sao Paulo, SP, Brazil
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Abstract

This is the protocol for a review and there is no abstract. The objectives are as follows:

To assess the efficacy and safety of nipple-sparing mastectomy and areola-sparing mastectomy for the treatment of invasive breast cancer and ductal carcinoma in situ in women.

Background

Description of the condition

Breast cancer is the most frequent non-skin cancer in women (23% of all cancers in women) with an estimated 1.15 million new cases and over 411,000 deaths reported worldwide in 2002 (Ferlay 2010).

Description of the intervention

The technique of subcutaneous mastectomy for the treatment of benign breast disease for women with a strong family history of breast cancer was first reported by Freeman 1962. The conventional method of mastectomy consists of the removal of the skin that overlies the breast including the nipple-areola complex. Today, nipple-sparing mastectomy is commonly used for women who are considered to be high risk and who are undergoing surgery as primary prevention for breast cancer (Hartmann 2001; Josephson 2000; Lostumbo 2010; Pennisi 1989).

How the intervention might work

The surgical management of breast carcinoma has evolved during the last two decades and improvements in the techniques mean that more conservative surgery and better cosmetic procedures can be achieved without compromising the oncological safety (Morrow 2002). Although the techniques for breast-conserving surgery in the treatment of breast cancer are well-established, many women prefer or require mastectomy to obtain local control of their disease. This is particularly true in cases of multifocal tumors and/or small-volume breasts in relation to the tumor, extensive ductal carcinoma in situ, women with clinical contraindications for radiotherapy and treatment of local recurrences (Singletary 2003). Conventional surgical therapy in these situations is mastectomy with the removal of the nipple-areola complex. This type of surgery has a cumulative incidence of local recurrence of about 2.3% after 20 years (Veronesi 1990).

Rising interest in improved cosmesis (i.e. cosmetic outcome) has led to the introduction of nipple-sparing mastectomy or areola-sparing mastectomy as an alternative to radical mastectomy (Chung 2008; Gerber 2009; Simmons 2002). Nipple-areola complex preservation results in higher psychological satisfaction and the perception of less mutilation among women (Loewen 2008).

Occult nipple involvement in breast cancer ranges from 0% to 58% (Andersen 1979; Banerjee 2008; Lagios 1979; Laronga 1999; Loewen 2008; Luttges 1987; Menon 1989; Morimoto 1985; Parry 1977; Quinn 1981; Rusby 2008; Santini 1989; Schecter 2006; Smith 1976; Verma 1997; Vyas 1998; Wetheim 1980) and areola involvement is 0.9% in patients with tumors less than 2 cm (Simmons 2002). This wide range may be explained by differences in the thoroughness of the pathological examinations and the design of these studies. The factors most commonly associated with the pathological involvement of the nipple are the size and location of the tumour, the distance of the tumour from the nipple, and axillary metastasis (Benediktsson 2008; Caruso 2006; Lagios 1979; Schecter 2006).

Despite the promising approach with nipple-sparing and areola-sparing mastectomy, the evidence from published studies seems preliminary. These studies include a small number of patients and a relatively short follow-up period (Benediktsson 2008; Caruso 2006; Gerber 2009; Horiguchi 2001; Petit 2009a; Sacchini 2006). In these non-randomised studies, the incidence of local recurrence ranges from 1.6% to 28% without radiotherapy (Benediktsson 2008; Caruso 2006), and 1.4% to 8.5% with radiation of the nipple-areola complex (Benediktsson 2008; Petit 2009a; Petit 2009b). Surgical complications such as skin necrosis (i.e. death of localized tissue or cells) have been described in up to 11% of patients without radiotherapy (Sacchini 2006) and up to 15% with the addition of radiotherapy to the nipple-areola complex (Petit 2009a).

Why it is important to do this review

Recently, nipple-sparing mastectomy has been proposed for the treatment of breast cancer. This technique retains the entire natural envelope of the skin and areola complex, and aims to create an aesthetic result that is closer to the natural state than breast reconstruction techniques. The efficacy and effectiveness of nipple-sparing mastectomy in the treatment of breast cancer is questionable, but it is estimated that local recurrence rates are very similar to breast-conserving surgery followed by radiotherapy (Veronesi 1990; Veronesi 2002). No systematic reviews or articles have been published that have analyzed the methodology of relevant studies with regards to their internal and external validity, and the risk of bias. Therefore, a systematic review on this topic is warranted.

Objectives

To assess the efficacy and safety of nipple-sparing mastectomy and areola-sparing mastectomy for the treatment of invasive breast cancer and ductal carcinoma in situ in women.

Methods

Criteria for considering studies for this review

Types of studies

We will search for randomized controlled trials (RCTs) as they provide the highest level of evidence. If no RCTs are found, we will expand our criteria to include non-randomized comparative studies (cohort and case-control studies).

Types of participants

Women with a diagnosis of ductal carcinoma in situ or invasive breast cancer, regardless of age, time of onset, or disease stage. The diagnosis must be in accordance with the histopathological criteria of the World Health Organization (WHO) (Tavassoli 2003).

We will include women who have undergone breast reconstructive surgery.

Types of interventions

Nipple-sparing mastectomy (that is, removal of all glandular breast tissue and preservation of the entire skin, nipple and areola) and areola-sparing mastectomy (that is, removal of all glandular breast tissue and nipple, and preservation of the entire skin and areola) compared with conventional mastectomy (removal of the skin that overlies the breast including the nipple and areola) for the treatment of ductal carcinoma in situ or invasive breast cancer, regardless of any adjuvant therapy.

We will include studies where women have undergone breast reconstructive surgery.

Types of outcome measures

Primary outcomes

Overall survival, considered separately for ductal carcinoma in situ and early breast cancer, and defined as the proportion of survivors in the studied and followed over period.

Secondary outcomes
  • Local recurrence incidence rate and time-to-event for recurrence during the follow-up period, considered separately for ductal carcinoma in situ and early breast cancer

  • Adverse events: local surgical complications or systemic surgical complications such as thromboembolic events

    • Local Complications

      • Explantation of implant/expander

      • Hematoma

      • Seroma

      • Rehospitalization

      • Skin necrosis (nipple, areola or flap necrosis)

      • Skin necrosis with revision surgery

      • Infection

  • Cosmetic results: patient and professional opinion

  • Quality of life including satisfaction with the decision to have nipple-sparing mastectomy, satisfaction with the cosmetic outcome, satisfaction with the medical process, psychological well-being, impact on body image, and impact on primary relationships and sexuality

Search methods for identification of studies

See: Breast Cancer Group for search methods used in reviews.

There will be no language restrictions on included studies. We will undertake full translations of all non-English language papers using local resources.

Electronic searches

We will search the following databases.

  1. The Cochrane Breast Cancer Group Specialised Register. The Cochrane Breast Cancer Group will search their Specialised Register. Details of the search strategies used by the Group for the identification of studies and the procedure used to code references are outlined in the Group's module (http://www.mrw.interscience.wiley.com/cochrane/clabout/articles/BREASTCA/frame.html). We will extract trials with the key words 'surgery', 'nipple sparing mastectomy', 'areola sparing mastectomy' and 'breast conserving surgery'.

  2. The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, current issue) (Appendix 1).

  3. MEDLINE (Appendix 2).

  4. EMBASE (Appendix 3).

  5. LILACS (Appendix 4).

  6. The WHO International Clinical Trials Registry Platform (ICTRP) search portal (http:www.who.it/trialsearch/AdvSearch.aspx) for all prospectively registered and ongoing trials (Appendix 5).

  7. ClinicalTrials.gov (http://www.clinicaltrials.gov/) (Appendix 6).

Searching other resources

Bibliography Searching

We will search the bibliographies of all included studies and review papers in order to identify other potentially suitable studies. We will obtain a copy of the full article for each reference reporting a potentially eligible trial, where possible. If this is not possible, we will attempt to contact authors to provide additional information.

Unpublished Literature

We will contact experts in this field and send letters to all authors of included studies requesting information on unpublished data or ongoing studies.

Data collection and analysis

Selection of studies

Two authors (BS, RR) will independently examine the titles and abstracts of articles identified in the search as potentially relevant trials. From this initial assessment, we will obtain full versions of all potentially relevant articles. We will consult a third author (JLBB) to help resolve any disagreements.

Data extraction and management

We will extract data and record the data on data extraction forms which we will develop. Two authors (BS and RR) will independently undertake full data extraction and consult a third author (JLBB) to help resolve disagreements. We will seek unpublished data concerning outcomes of interest from authors by letter, as stated above.

We will include the following information from individual studies on data extraction forms:

  • publication details;

  • study design, study setting, inclusion/exclusion criteria;

  • patient population e.g. age, type of surgical procedure, type of tumor;

  • details of intervention;

  • outcome measures; and

  • withdrawals, length and method of follow-up and the number of participants followed up.

For non-randomized studies we will also record the following information:

  • methods used to control for confounders;

  • adjusted and unadjusted outcome measures.

Assessment of risk of bias in included studies

We will follow the Cochrane Collaboration's tool for assessing risk of bias as described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011), the Cochrane EPOC Group's risk of bias criteria (Cochrane EPOC Group 2013), and recommendations by Norris 2013. Assessment of the methodological quality of each study will be undertaken independently by two authors (BS, RR) and risk of bias will be assessed under the following domains: selection bias, performance/detection bias, attrition bias, reporting bias and other bias. For each risk of bias domain and its associated specific questions outlined below, we will assign either 'High risk', 'Low risk', or 'Unclear risk'.

Selection Bias
Was the allocation sequence adequately generated?
  • Score "Low risk" if a random component in the sequence generation process is described (e.g. referring to a random number table)

  • Score "High risk" when a non-random method is used (e.g. performed by date of admission)

  • Non-randomized studies should be scored "High risk". Score "Unclear risk" if not specified in the paper

Was the allocation adequately concealed?
  • Score "Low risk" if participants and investigators enrolling participants could not foresee assignment (e.g. because a centralized randomization scheme, an on-site computer system or sealed opaque envelopes were used)

  • Non-randomized studies should be scored "High risk"

  • Score "Unclear risk" if not specified in the paper

For non-randomized studies we will also consider the following questions.

Were baseline outcome measurements similar?
  • Score "Low risk" if performance or patient outcomes were measured prior to the intervention, and no important differences were present across study groups

  • Score "High risk" if important differences were present and not adjusted for in the analysis

  • Score "Unclear risk" if not specified in the paper

Were baseline characteristics similar?
  • Score "Low risk" if baseline characteristics of the study and control providers are reported and similar

  • Score "Unclear risk" if it is not clear in the paper (e.g. characteristics are mentioned in the text, but no data were presented)

  • Score "High risk" if there is no report of characteristics in text or tables or if there are differences between control and intervention providers

Was there adequate adjustment for confounding?
  • Score "Low risk" if appropriate methods were used to adjust for potential confounding

  • Score "Unclear risk" if the methods used to adjust for confounding were not reported in the paper

  • Score "High risk" if potential confounding from the following variables has not been addressed: adjuvant radiotherapy, age, surgical techniques, stage of disease, ductal carcinoma in situ or invasive breast cancer, and chemotherapy

Performance/detection bias
Was knowledge of the allocated interventions adequately prevented during the study?
  • Score "Low risk" if the authors state explicitly that the primary outcome variables were assessed blindly, or the outcomes are objective, e.g. length of hospital stay

  • Score "High risk" if the outcomes were not assessed blindly

  • Score "Unclear risk" if not specified in the paper

Attrition bias
Were incomplete outcome data adequately addressed?
  • Score "Low risk" if missing outcome measures were unlikely to bias the results (e.g. reasons for missingness unlikely to be related to true outcome, missing outcome data balanced in numbers across intervention groups with similar reasons for missing data or missing data have been imputed using appropriate methods)

  • Score "High risk" if missing outcome data was likely to bias the results

  • Score "Unclear risk" if not specified in the paper

Reporting bias
Were reports of the study free from selective outcome reporting?
  • Score "Low risk" if there is no evidence that outcomes were selectively reported (e.g. the study had a protocol pre-specifying the outcomes, or all relevant outcomes in the methods section are reported in the results section)

  • Score "High risk" if some pre-specified outcomes are subsequently omitted from the results

  • Score "Unclear risk" if not specified in the paper

Were reports of the study free from selective analysis reporting?
  • Score "Low risk" for each outcome if there is no evidence that analyses were selectively reported (e.g. analyses were defined in the methods section of the protocol or paper)

  • Score "High risk" if there is evidence of selective analysis reporting (e.g. multiple adjusted analyses have been carried out and only one reported, or unusual cut-points have been used for categorizing an outcome)

  • Score "Unclear" risk if unclear from the paper

Classification of study designs

We will include various study designs and define them as follows.

  • Prospective cohort study: a group of exposed and non-exposed individuals that have been followed over time to compare incidence (or rate of death from disease) between the groups (Gordis 1996). In prospective cohort studies, the recruitment, exposure/intervention, and outcomes must all have occurred after setting up the study.

  • Retrospective cohort study: a group of exposed and non-exposed individuals that have been followed over time to compare incidence (or rate of death from disease) between the groups (Gordis 1996). In retrospective cohort studies, outcomes can have occurred prior to setting up the study or be collected afterwards, or both.

  • Case-control study: a study that compares people with a specific outcome of interest (cases) with people from the same source population but without that outcomes (controls), to examine the association between the outcome prior exposure.

Measures of treatment effect

We will report time-to-event outcomes (e.g. overall survival and local recurrence) as hazard ratios (HRs) with 95% confidence intervals (CIs). If necessary HRs will be estimated using the methods of Parmar 1998. If it is not possible to estimate HRs from all studies, the number of events (e.g. deaths or recurrences) over 5 and 10 years of follow-up will be treated as dichotomous outcomes. We will report dichotomous outcomes (e.g. recurrence, distant disease, explantation of implant/expander, hematoma, seroma, rehospitalization, skin necrosis (nipple, areola or flap necrosis), skin necrosis (nipple, areola or flap necrosis) with revision surgery, infection and cosmetic results) as risk ratios (RRs) and risk differences (RDs) with 95% CIs. We will pool the data for meta-analysis using the pooled log-RR, where appropriate. We will report continuous outcomes (e.g. quality of life) as mean differences (MDs) with 95% CIs.

Considering the current approach for ductal carcinoma in situ or invasive breast cancer, it seems reasonable to consider the treatment effect reading the primary outcome as a non-inferiority question. Thus, the non-inferiority bound for the HR will be 1.13 (based on a 10-year survival rate of 24% for conventional mastectomy with a cut-off value of 27% for nipple/areola-sparing mastectomy). For local recurrence the non-inferiority bound for the HR will be 2.67 (based on 3% 10-year local recurrence for conventional mastectomy with a cut-off value of 8% for nipple/areola-sparing mastectomy).

Unit of analysis issues

We anticipate that the appropriate unit of analysis will be by individual patient, rather than surgical unit, hospital or center.

Dealing with missing data

Where data are missing or unsuitable for analysis (e.g. intention-to-treat analysis was not used), we will contact the authors to request further information. Where data are missing to the extent that the study cannot be included in the meta-analysis and attempts to retrieve data have been exhausted, we will present the results in the review and discuss in the context of the findings.

Assessment of heterogeneity

If appropriate, we will assess statistical heterogeneity using the chi-squared (Chi2) statistic (P value less than 0.1). We will also assess heterogeneity between studies using the I2 statistic to examine the percentage of total variation across studies due to heterogeneity rather than chance. An I2 value of 30% to 60% may represent moderate heterogeneity, while values greater than 50% may be considered substantial heterogeneity (Higgins 2011).

We will investigate the following factors as potential causes of heterogeneity in the included studies using the framework below.

  1. Clinical diversity: includes study location and setting, full characteristics of participants, co-morbidity and treatments that participants may be receiving on trial entry. We will consider how outcomes were measured, the definition of outcomes, and how they were recorded. Depending upon the extent of the clinical diversity, we will either analyze studies separately or present the results using a narrative approach.

  2. Methodological diversity: includes assessment of the randomization process, study quality, and analytical method.

Assessment of reporting biases

We will search for protocols of included trials using PubMed (National Library of Medicine) and through the UK and other trial registries, where possible. We will contact study authors to attempt to establish a full data set or reasons for the non-reporting of certain outcomes.

Data synthesis

We will synthesize data using the Cochrane Collaboration's statistical software, Review Manager 2013. We will base the choice of using fixed-effect or random-effects models for data synthesis on a number of factors. Where significant clinical or methodological heterogeneity exists, we will use a random-effects model. Otherwise we will use the fixed-effect model.

We will combine data using the inverse variance method on the log-HR scale for time-to-event outcomes, on the log-RR scale for dichotomous outcomes and on the MD scale for continuous outcomes. For random-effects meta-analysis we will use the Dersimonian and Laird method.

Where the data are too diverse for combining effect sizes in a meaningful or valid manner, we will present the results of individual studies in table and graphical format and use a narrative approach to summarize the data.

Subgroup analysis and investigation of heterogeneity

As we expect a small number of published studies, we do not envisage that it will be possible to perform subgroup analyses. However, we would like to consider the following subgroups.

  1. Patients who received adjuvant radiotherapy versus patients who did not have radiotherapy.

  2. Younger (< 50 years of age) versus older (≥ 50 years of age) women.

  3. Surgical techniques.

  4. Cancer stage as per the TNM (the size and/or extent of the primary tumor (T), the amount of spread to nearby lymph nodes (N), and the presence of metastasis (M) or secondary tumors) classification system (NCI 2013).

  5. Systemic therapy (chemotherapy or endocrine therapy) versus no systemic therapy.

Sensitivity analysis

We will conduct sensitivity analyses by either excluding trials of low methodological quality or quasi-randomized studies. We will consider and discuss the results of these analyses in comparison to the overall findings.

Acknowledgements

The authors wish to thank all the members of the Cochrane Breast Cancer Group for their hard work in editing and reviewing the review protocol. Also, we thank the Cochrane Handbook Study Group from the Brazilian Cochrane Center for the methodological support.

Appendices

Appendix 1. CENTRAL search strategy

#1 MeSH descriptor: [Breast Neoplasms] explode all trees

#2 MeSH descriptor: [Mastectomy, Segmental] explode all trees

#3 MeSH descriptor: [Mastectomy, Subcutaneous] explode all trees

#4 segmental mastectom* or subcutaneous mastectom* or breast conserving surger* or partial mastectom* or nipple-sparing mastectom* or areola-sparing mastectom* or local excision mastectom* or limited resection mastectom*

#5 #2 or #3 or #4

#6 #1 and #5

Appendix 2. MEDLINE search strategy

# ▲ Searches
1exp Breast Neoplasms/
2(breast cancer or breast neoplasm or breast carcinoma or breast tumour or breast tumor).mp.
31 or 2
4exp Mastectomy, Segmental/
5exp Mastectomy, Subcutaneous/
6segmental mastectom*.mp.
7subcutaneous mastectom*.mp.
8breast conserving surger*.mp.
9partial mastectom*.mp.
10nipple-sparing mastectom*.mp.
11areola-sparing mastectom*.mp.
12local excision mastectom*.mp.
13limited resection mastectom*.mp.
14(limited resection adj5 mastectom*).mp.
154 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14
163 and 15
17Animals/
18Humans/
1917 not 18
2016 not 19

Appendix 3. EMBASE search strategy

#1 'breast neoplasms'/exp OR 'breast neoplasms' OR 'breast cancer'/exp OR 'breast cancer' OR 'breast carcinoma'/exp OR 'breast carcinoma' OR 'breast tumour' OR 'breast tumor'/exp OR 'breast tumor'

#2 'segmental mastectomy'/exp OR 'segmental mastectomy'

#3 'subcutaneous mastectomy'/exp OR 'subcutaneous mastectomy'

#4 'breast conserving surgery'/exp OR 'breast conserving surgery'

#5 'partial mastectomy'/exp OR 'partial mastectomy'

#6 'nipple-sparing mastectomy'

#7 'areola-sparing mastectomy'

#8 'local excision mastectomy'

#9 'limited resection mastectomy'

#10 'limited resection' NEAR/5 mastectom*

#11 #2 OR #3 OR #4 OR #5 OR #6 OR #7 OR #8 OR #9 OR #10

#12 #1 AND #11

#13 #12 AND [humans]/lim AND [embase]/lim

Appendix 4. LILACS search strategy

Search strategy
#1(Mastectomia Segmentar) OR (Mastectomia Segmental ) OR (Mastectomy, Segmental ) OR (Lumpectomy) OR (Partial Mastectomy) OR (Breast-Conserving Surgery) OR (Ex E04.466.701)
#2(Mastectomy, Subcutaneous) OR (Mastectomia Subcutânea) OR (Mastectomia Subcutânea) OR (Ex E04.466.823)
#3(Breast Neoplasms) OR (Neoplasias de la Mama) OR (Neoplasias da Mama) OR (Cancer of Breast) OR (Breast Cancer) OR (Breast Tumors)
#4 #1 OR #2
#5 #3 AND #4

Appendix 5. WHO ICTRP search portal search strategy

Basic searches

  1. Nipple-sparing mastectomy AND breast cancer

  2. Areola-sparing mastectomy AND breast cancer[ft1] 

Advance searches

Title: Nipple and areola sparing mastectomy for the treatment of breast cancer

Recruitment Status: ALL

Condition: breast cancer

Intervention: nipple-sparing mastectomy OR areola-sparing mastectomy OR mastectomy OR breast conserving surgery OR NAC

Recruitment Status: ALL

Condition: breast cancer

Intervention: nipple AND areola AND mastectomy

Recruitment Status: ALL

Appendix 6. ClinicalTrials.gov search strategy

Basic searches

  1. Nipple-sparing mastectomy AND breast cancer

  2. Areola-sparing mastectomy AND breast cancer

Advance searches

Title: Nipple and areola sparing mastectomy for the treatment of breast cancer

Recruitment: All Studies

Study Results: All Studies

Study Type: All Studies

Gender: All Studies

Condition: breast cancer

Intervention: nipple-sparing mastectomy OR areola-sparing mastectomy OR mastectomy OR segmental mastectomy OR breast conserving surgery OR NAC

Recruitment: All Studies

Study Results: All Studies

Study Type: All Studies

Gender: All Studies

Condition: breast cancer

Intervention: nipple AND areola AND mastectomy

Recruitment: All Studies

Study Results: All Studies

Study Type: All Studies

Gender: All Studies

What's new

DateEventDescription
9 November 2012New citation required and major changesThe previous version of this protocol included nipple-, areola- and skin-sparing mastectomy for breast cancer. Due to nipple- and areola-sparing mastectomy being different treatments to skin-sparing mastectomy, the scope of this protocol has been revised to review nipple- and areola-sparing mastectomy only
9 November 2012AmendedThe scope of this protocol has changed to include nipple- and areola-sparing mastectomy only. In addition, the types of studies have been extended to include non-randomised study designs

Contributions of authors

Bruna Salani - background, objectives, outcome definitions and protocol organization.
Rachel Riera - methodological topics and protocol organization.
Alvaro Atallah - methodological topics.
Jessica Barrett - methodological topics, statistical analysis.
José Luiz Barbosa Bevilacqua - background, objectives and outcome definitions.

Declarations of interest

The authors have no conflict of interest.

Sources of support

Internal sources

  • None, Not specified.

External sources

  • None, Not specified.

Ancillary