Surgical and Oncologic Outcomes After Robotic Nipple Sparing Mastectomy and Immediate Reconstruction

Study Overview
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Brief Summary
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Robotic mastectomy with immediate reconstruction was introduced by Toesca et al. in 2015. Since then, several studies have reported the safety and feasibility of robotic nipple-sparing mastectomy with immediate reconstruction. However, most studies were conducted by single centers and had small samples. Furthermore, there is a lack of studies comparing surgical and oncologic outcomes between robotic nipple-sparing mastectomy and conventional nipple-sparing mastectomy. For this reason, this study evaluates surgical and oncologic outcomes of robotic nipple-sparing mastectomy with immediate reconstruction using international multi-center data.

Detailed Description
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This study is an international multi-center pooled analysis using prospective and retrospective studies to evaluate surgical and oncologic outcomes of robotic nipple-sparing mastectomy with immediate reconstruction. Raw data for robotic or conventional nipple-sparing mastectomy from Severance Hospital, Samsung Medical Center, the European Institute of Oncology, Changhua Christian Hospital, and Gustave Roussy is collected. Among them, Severance Hospital takes the lead at performing analysis from the data. Storage and disposal of patients' records are managed by each researcher. In the analysis process, although the collaborators can request records from Severance Hospital if necessary, they are only supposed to be provided computerized data which were originally clinical data from patients who already ended treatments. In this case, individual identifying data and medical records are not shown. Clinicopathologic variables including operation times, hospital stay, medical history, smoking history, family history, BMI, menopausal status, specimen weight, TNM stage, grade, histological type, estrogen receptor, progesterone receptor, HER2, Ki 67, and perivascular involvement are analyzed. Postoperative complications within 30 days are collected and classified by the Clavien-Dindo grade. Locoregional recurrence-free survival and local and systemic recurrences are examined. Patients whose data have been retrospective for at least one month are to be examined. Patient's and surgeon's satisfaction using Breast Q is evaluated. Categorical variables are examined using the chi-square test or Fisher's exact test if indicated. Continuous variables are examined using the independent t-test or ANOVA if indicated. The estimated sample size from the four institutions is about 300 cases for robotic nipple-sparing mastectomy and matched cases for conventional nipple-sparing mastectomy. Propensity matching analysis is applied to reduce confounding factors.

Official Title
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Surgical and Oncologic Outcomes After Robotic Nipple Sparing Mastectomy and Immediate Reconstruction : an International Multicenter Pooled Analysis

Conditions
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Postoperative Complications, Recurrence, Breast Neoplasms, Breast Cancer, BRCA1 Mutation, BRCA2 Mutation, Surgery, Surgery--Complications

Intervention / Treatment
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* Procedure: Robotic nipple sparing mastectomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women who underwent nipple sparing mastectomy and immediate reconstruction Women with early breast cancer Women with germline BRCA 1/2 mutation or germline mutations in genetic susceptibility genes Women with interstitial mastopathy Women with risk-reducing mastectomy or contralateral mastectomy Exclusion Criteria: Male patients Women with stage IV disease at diagnosis Women who underwent previous breast cancer surgery Women who received prior radiotherapy for the ipsilateral breast
Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Robotic nipple sparing mastectomy group/RNSM<br>Cases or Patients who underwent robotic nipple-sparing mastectomy and immediate reconstruction are enrolled in this arm. Robotic nipple-sparing mastectomy should be performed using robotic surgical systems. Robotic surgical systems include da Vinci S,Si, X, Xi, and SP systems. Axillary or lateral incisions are used for this procedure. Immediate reconstruction includes tissue expander insertion, direct-to-implant, latissimus dorsi flap, transverse abdominis rectus muscle flap, or deep inferior epigastric perforators flap. Cases with robotic mastectomy without immediate reconstruction are excluded. The estimated sample size for this arm is 300 cases. | Procedure: Robotic nipple sparing mastectomy<br>* Robotic nipple sparing mastectomy means nipple sparing mastectomy performed using robotic surgical systems.<br>* Other names: Robot-assisted nipple areolar complex and skin sparing mastectomy;|
| Conventional nipple sparing mastectomy group/CNSM<br>Cases or Patients who underwent conventional nipple-sparing mastectomy and immediate reconstruction are enrolled in this arm. Conventional nipple-sparing mastectomy should not be performed using robotic or endoscopic surgical systems. Axillary or lateral incisions that are similar to incisions in robotic nipple-sparing mastectomy are not allowed. Other than axillary or lateral incisions can be performed for this procedure. Immediate reconstruction includes tissue expander insertion, direct-to-implant, latissimus dorsi flap, transverse abdominis rectus muscle flap, or deep inferior epigastric perforators flap. Cases with nipple-sparing mastectomy without immediate reconstruction are excluded. The estimated sample size for this arm is 300 cases. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative complication rates in 30 days | Postoperative complication rates are calculated as total number of postoperative complication cases per total operation cases. | Postoperative 30 days | 
| Clavien-Dindo grade of postoperative complications | Clavien-Dindo grade of postoperative complications is evaluated. The highest grade of postoperative complications are used for the analysis. | Postoperative 30 days | 
| Nipple necrosis rates | Nipple necrosis rates are calculated as number of total nipple necrosis cases per total operation cases. | Postoperative 30 days | 
| Recurrence free survival (RFS) | Events of RFS includes locoregional recurrence, distant recurrence, and death. Contralateral breast cancer and second primary malignancy are considered to be censored data. | Postoperative 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Operation times | Mastectomy time or reconstruction time | Time during operation | 
| Locoregional recurrence-free survival (LRFS) | In breast tumor recurrences (IBTR), regional recurrences including axillary, internal mammary, or supraclavicular lymph node recurrences, and death without any cause are events of locoregional recurrence-free survival. Five year LRFS is measured. Distant metastasis, contralateral breast cancer and second primary malignancy are considered to be censored data. | Postoperative 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Robotic mastectomy, Breast neoplasms, Postoperative complications, Recurrence, Prognosis, Survivals, Nipple sparing mastectomy, Immediate reconstruction