Robot-assisted vs. Open Nipple-sparing Mastectomy With Immediate Breast Reconstruction

A Prospective Multicenter Randomized Clinical Trial: Robot-assisted vs. Open Nipple-sparing Mastectomy With Immediate Breast Reconstruction (ROM) Trial

Research Purpose The present study is designed to generate the strongest evidence available on the role of robotic surgical systems in breast cancer surgery and to elucidate the clinical value of immediate breast reconstruction (IBR) conducted in conjunction with robot-assisted nipple-sparing mastectomy (RNSM).

Study Design Overview This study is a prospective, multicenter, randomized clinical trial (ROM Trial) designed to compare the oncologic outcomes of robot-assisted nipple-sparing mastectomy (RNSM) with conventional nipple-sparing mastectomy (CNSM), which includes both traditional and open-chest approaches. Previous retrospective studies of robot-assisted endoscopic surgery have suggested a short learning curve, demonstrating technical feasibility and reproducibility even for less experienced surgeons. However, the absence of rigorously designed randomized clinical trials remains a major global barrier to the broader adoption of robotic breast surgery.

In the ROM Trial, eligible patients who provide written informed consent will be randomly assigned in a 1:1 ratio to undergo either RNSM or CNSM. Participants will be blinded to group allocation until the day of surgery (single-blind design). Immediate breast reconstruction (IBR) will be performed in all patients, with the reconstruction method determined in consultation with the breast and/or plastic surgeon following mastectomy.

Background Robot-assisted nipple-sparing mastectomy (RNSM) has emerged as an approach for both breast cancer treatment and risk-reducing mastectomy in women carrying high-risk pathogenic variants. Although several studies have reported that RNSM is a feasible procedure, concerns remain that it is performed only by a small number of specialized surgeons, and data on oncologic outcomes and patient-reported outcomes (PROs) remain limited. Recently, the United States Food and Drug Administration and several expert surgeons have cautioned that robotic breast surgery should be performed only by highly trained specialists, and that the benefits, risks, and alternative treatment options must be thoroughly discussed with patients to ensure fully informed decision-making.

To promote the safe and standardized application of RNSM, the Korea Robot-Endoscopy Minimal Access Breast Surgery Study Group (KoREa-BSG) was established with the mission to evaluate, standardize, and disseminate this advanced surgical technique.

Study Design We designed a prospective, multicenter, randomized clinical trial (Robot vs. Open Nipple-sparing Mastectomy Trial; ROM Trial) to evaluate the oncologic outcomes of RNSM with immediate breast reconstruction (IBR), compared with conventional open nipple-sparing mastectomy (CNSM) with IBR.

Previous retrospective studies on robot-assisted endoscopic breast surgery have demonstrated a short learning curve, suggesting that the technique is feasible and reproducible even for less experienced surgeons. However, the absence of rigorously designed randomized controlled trials has been a major limitation in expanding the global adoption of robotic breast surgery. The ROM Trial was therefore established to address this unmet need.

Data Collection Clinical and pathological data to be collected include: height, weight, breast volume/weight, age, germline likely pathogenic/pathogenic mutation status, affected breast, bilaterality, breast ptosis, tumor size, TNM stage, histologic grade, histologic type, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), Ki-67 index, nipple involvement, neoadjuvant/adjuvant treatment status, postoperative complications (Clavien-Dindo classification), operative time, margin involvement, postoperative drainage amount/duration, risk-reducing mastectomy (RRM) status, reconstruction type, recurrence status, healthcare cost data, and follow-up information.

Patient Satisfaction Assessment Between 3 and 12 months (±30 days) after the final surgery, patients will be surveyed using the validated Korean version of the BREAST-Q questionnaire to evaluate satisfaction with surgery.

Cost-Effectiveness Assessment (Optional) Cost-effectiveness according to surgical method will be evaluated between 3 and 12 months (±30 days) after the final surgery, using the Korean version of the EuroQol 5-Dimension (EQ-5D) questionnaire.

Inclusion Criteria:

• Adult women (≥19 years) scheduled to undergo therapeutic mastectomy for breast cancer who desire immediate breast reconstruction (IBR).
• Breast cancer classified as clinical TNM stage 0 to IIIA, based on preoperative evaluation according to the 8th edition of the AJCC anatomic staging system.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion Criteria:

• Patients scheduled for breast-conserving surgery or deemed ineligible for immediate breast reconstruction (IBR).

• Clinical evidence of nipple or skin involvement on preoperative evaluation.

  • Pregnant or breastfeeding women.
  • Tumors consisting exclusively of lobular carcinoma in situ (LCIS).
  • Paget's disease of the breast.
  • Inflammatory breast cancer.
  • Male breast cancer.
  • Clinical stage IIIB-IV disease on preoperative evaluation.
  • breast size equal to or larger than cup E
  • History of breast cancer or bilateral breast cancer (including metachronous or synchronous disease).
  • History of non-breast malignancy, with the exception of non-melanoma skin cancer or papillary/follicular thyroid carcinoma.
  • Special histologic subtypes of breast tumors (e.g., phyllodes tumor, sarcoma, lymphoma).
  • Age >70 years.
  • American Society of Anesthesiologists (ASA) physical status classification grade ≥4.
  • Inability to provide informed consent.
  • History of prior chest radiotherapy.
  • Patients who have not undergone preoperative testing for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV), which is required for liability insurance coverage.