Endoscopic Nipple-Sparing Mastectomy Through a Single Axillary Incision in Breast Cancer (Mini-B)

MINI-B - Minimally Invasive Endoscopic Mastectomy Using a Single Axillary Incision in Breast Cancer Patients: a Prospective Cohort Study

This single-center prospective study will evaluate the feasibility and safety of endoscopic nipple-sparing mastectomy (E-NSM) performed through a single axillary incision in selected women with breast cancer undergoing direct-to-implant breast reconstruction. The study will assess procedural feasibility, completeness of resection, short-term postoperative complications, and patient-reported outcomes

Study Overview

• Status: Recruiting
• Conditions: Breast Cancer; Breast Cancer - Ductal Carcinoma in Situ (DCIS)
• Intervention / Treatment: Procedure: Endoscopic Nipple-Sparing Mastectomy (E-NSM)

Detailed Description

MINI-B is a single-institution prospective study conducted at the Breast Surgery Unit of Candiolo Cancer Center, Istituto di Candiolo FPO-IRCCS, Torino, Italy. The study will enroll 10 consecutive adult female patients with early-stage invasive breast cancer or ductal carcinoma in situ who are candidates for nipple-sparing mastectomy with direct-to-implant reconstruction and are suitable for a minimally invasive approach. The investigated procedure is endoscopic nipple-sparing mastectomy performed through a single hidden axillary incision using a standardized technique modeled on the robotic nipple-sparing mastectomy procedure already in use at the institution. The study will evaluate feasibility through technical and perioperative parameters, assess resection completeness by margin status, record postoperative complications over 3 months, and collect patient-reported quality-of-life data using BREAST-Q/EORTC questionnaires.

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Antonio Toesca, MD; Phone Number: +39 0119933628; Email: antonio.toesca@ircc.it
• Study Contact Backup: Name: Giada Pozzi, MD; Phone Number: +39 0119933676; Email: giada.pozzi@ircc.it

Study Locations

• Italy
  • Turin
    • Candiolo, Turin, Italy, 10060
      • Recruiting
      • Breast Unit
      • Contact: Antonio Toesca, MD; Phone Number: +39 0119933628; Email: antonio.toesca@ircc.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Female participants aged 18 years or older.
• Diagnosis of early-stage invasive breast cancer or ductal carcinoma in situ, including multifocal or multicentric disease.
• Candidate for nipple-sparing mastectomy with immediate direct-to-implant reconstruction.
• Small- to medium-sized breasts with ptosis grade 2 or less.
• Written informed consent provided.

Exclusion Criteria:

• Preoperative evidence of skin involvement, nipple-areola complex involvement, lymph-node metastases, inflammatory breast cancer, Paget's disease, mesenchymal breast tumors, or recurrent breast cancer.
• Previous ipsilateral breast surgery.
• Previous thoracic radiation therapy.
• Heavy smoking (>20 cigarettes/day), uncontrolled diabetes mellitus, or body mass index >30.
• ASA score 3 or higher.
• Ongoing pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Single-Arm Endoscopic Nipple-Sparing Mastectomy; Eligible participants with breast cancer or ductal carcinoma in situ will undergo endoscopic nipple-sparing mastectomy through a single axillary incision, with immediate direct-to-implant breast reconstruction	Procedure: Endoscopic Nipple-Sparing Mastectomy (E-NSM); Endoscopic nipple-sparing mastectomy performed through a single extra-mammary axillary incision using a standardized minimally invasive surgical technique; immediate direct-to-implant reconstruction will be performed according to institutional practice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Successful completion of endoscopic nipple-sparing mastectomy without conversion to open surgery	Number of participants in whom the planned endoscopic nipple-sparing mastectomy through a single axillary incision is completed without conversion to an open technique	During the index surgical procedure
Total operative time	Operative time for the endoscopic nipple-sparing mastectomy procedure, measured from skin incision to completion of wound closure	During the index surgical procedure
Negative surgical margin rate	Number of participants with tumor-free surgical margins on final pathological examination of the mastectomy specimen	From surgery to final pathology assessment, up to 30 days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Length of postoperative hospitalization	Postoperative length of hospital stay, measured as the number of days from the date of surgery to the date of hospital discharge.	From the date of surgery to hospital discharge during the index hospitalization, assessed up to 30 days
Participants with at least 1 postoperative complication	Number of participants with at least 1 postoperative complication, defined as nipple-areola complex necrosis, mastectomy skin flap necrosis, surgical-site infection, postoperative bleeding/hematoma, seroma requiring aspiration or drainage, or wound dehiscence.	From the date of surgery to 3 months after surgery
Participants with at least 1 major postoperative complication	Number of participants with at least 1 major postoperative complication, defined as any postoperative complication requiring reoperation or rehospitalization, or resulting in implant loss	From the date of surgery to 3 months after surgery
BREAST-Q Satisfaction With Breasts score	Patient-reported satisfaction with breasts assessed using the BREAST-Q Reconstruction Module, Satisfaction With Breasts scale. Scores range from 0 to 100, with higher scores indicating greater satisfaction and a better outcome	Baseline (preoperative assessment) and 3 months after surgery
BREAST-Q Reconstruction Module Psychosocial Well-Being score	Patient-reported psychosocial well-being assessed using the BREAST-Q Reconstruction Module, Psychosocial Well-Being scale. Scores range from 0 to 100, with higher scores indicating better psychosocial well-being	Baseline (preoperative assessment) and 3 months after surgery
BREAST-Q Reconstruction Module Physical Well-Being: Chest score	Patient-reported physical well-being of the chest assessed using the BREAST-Q Reconstruction Module, Physical Well-Being: Chest scale. Scores range from 0 to 100, with higher scores indicating better physical well-being	Baseline (preoperative assessment) and 3 months after surgery
BREAST-Q Reconstruction Module Sexual Well-Being score	Patient-reported sexual well-being assessed using the BREAST-Q Reconstruction Module, Sexual Well-Being scale. Scores range from 0 to 100, with higher scores indicating better sexual well-being	Baseline (preoperative assessment) and 3 months after surgery

Collaborators and Investigators

• Sponsor: Fondazione del Piemonte per l'Oncologia

Study record dates

Study Major Dates

• Study Start (Actual): June 11, 2025
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: March 19, 2026
• First Submitted That Met QC Criteria: March 30, 2026
• First Posted (Actual): April 2, 2026

Study Record Updates

• Last Update Posted (Actual): April 2, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Mastectomy; Breast; E-NSM; Endoscopic Nipple-Sparing
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms
• Other Study ID Numbers: 003-FPO25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No