Breast Cancer Classified as TNM Stage 0-IIIaROMNCT05490433
Robot-assisted vs. Open Nipple-sparing Mastectomy With Immediate Breast Reconstruction
A study testing Robot-assisted Nipple-Sparing Mastectomy (RNSM) and Conventional nipple sparing mastectomy(CNSM) in people with Breast Cancer Classified as TNM Stage 0-IIIa, run by Yonsei University at 17 sites in South Korea.
Trial summary
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). Read more about this study
- Who is it for?
- Ages 19 to 70 years, women only
- Conditions the study is for
- Breast Cancer Classified as TNM Stage 0-IIIa
- What is being tested?
- Robot-assisted Nipple-Sparing Mastectomy (RNSM) and Conventional nipple sparing mastectomy(CNSM)
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 790 participants
- Where
- 17 sitesSouth Korea
- Study dates
- 26 Oct 2022to Jun 2032
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 70 years
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Show all 17Show fewer
- 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.
Trial locations and contacts
17 sites in 1 country. Contact the study team or a site near you to ask about taking part.
17 sites in 1 country
South Korea17 sites, 17 recruiting
- Recruiting
Samsung Changwon Medical Center
Changwon
Hee Jun Choi, M.D. PhD, 82-10-9955-5801, heejun1.choi@samsung.com
- Recruiting
Keimyung University Dongsan Hospital
Daegu
Moo Hyun Lee, MD, 82-10-2315-0197, mhlee197@gmail.com
- Recruiting
Kyungpook National University Chilgok Hospital
Daegu
Jeeyeon Lee, MD, PhD, 82-10-5134-0001, j.lee@knu.ac.kr
- Not yet recruiting
Yeungnam University Medical Center
Daegu
Jeong eun Choi, MD, PhD, 82-10-2524-7017, cjegs@yu.ac.kr
- Recruiting
Myongji Hospital
Goyang-si
Hyukjai Shin, M.D. PhD, 82 10 8803 5433, drgsshj@gmail.com
- Recruiting
The Catholic University of Korea, Incheon ST. Mary's Hospital
Incheon
Young Joon Kang, M.D. PhD., 82-10-2638-3847, yjkang.md@gmail.com
- Recruiting
Kosin University Gospel Hospital
Pusan
seong jeong, MD, 82-10-3820-5483, ist2000good@daum.net
- Not yet recruiting
Chungnam National University Sejong Hospital
Sejong
Younju Lee, 82-10-3356-4405, jaennejuya@cnuh.co.kr
- Not yet recruiting
Asan Medical Center
Seoul
Beom Seok Go, PhD, 82-10-5313-4537, spdoctorko@gmail.com
- Not yet recruiting
Gangnam Severance Hospital
Seoul
Sung Gwe Ahn, M.D, Ph.D, 82-10-9948-0247, ASG2004@yuhs.ac
- Recruiting
Korea University Anam Hospital
Seoul
Ji Young You, MD, PhD, 82-10-3554-7482, mdjean83@gmail.com
- Not yet recruiting
Korea University Ansan Hospital
Seoul
Hye yoon Lee, M.D., 82-31-412-7660, heygemma@korea.ac.kr
- Recruiting
Samsung Medical Center
Seoul
Jai Min Ryu, MD, PhD, 82-10-9933-5243, sheol1981@naver.com
- Recruiting
Seoul National University Hospital
Seoul
Han-Byoel Lee, MD, PhD, 82-10-9035-8211, hblee80@gmail.com
- Not yet recruiting
Soonchunhyang University Hospital Seoul
Seoul
Ji Hyun Lee, M.D., amearashi@schmc.ac.kr
- Recruiting
Yonsei University Health System, Severance Hospital
Seoul
Hyung Seok Park, MD, PhD, 82-10-6760-2974, imgenius@yuhs.ac
- Recruiting
Yongin Severance Hospital
Yongin-si
Joo Heung Kim, M.D., 82-10-7203-1555, PIANAC@yuhs.ac
About this study
Official title: 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.
Read the detailed description
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.
- Being tested
- Robot-assisted Nipple-Sparing Mastectomy (RNSM), Conventional nipple sparing mastectomy(CNSM)
- Keywords
- Breast cancer
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Robot-assisted Nipple-Sparing Mastectomy (RNSM)Procedure or surgery
Patients undergoing robot-assisted nipple-sparing mastectomy (RNSM) with immediate breast reconstruction (IBR) will be enrolled in this group. RNSM will be performed using robotic surgical platforms, including the da Vinci S, Si, X, Xi, and SP systems. The procedure will be conducted through an axillary or lateral chest wall incision.
During surgery, posterior areolar tissue sampling for frozen section biopsy will be recommended. If suspicious lesions are detected at the superficial or posterior margins, frozen section biopsy of those lesions will also be performed. When tumor involvement of the nipple-areola complex (NAC), superficial margin, or posterior margin is confirmed by frozen section biopsy, additional resection including the skin and NAC, or postoperative radiotherapy, will be considered.
Conventional nipple sparing mastectomy(CNSM)Procedure or surgery
Patients who undergo conventional nipple-sparing mastectomy (CNSM) with immediate breast reconstruction (IBR) will be enrolled in this group. CNSM is performed without the use of robotic or endoscopic surgical systems, and all types of skin incisions are permitted.
During surgery, posterior areolar tissue sampling for frozen section biopsy is recommended. If suspicious lesions suggesting tumor involvement are identified at the superficial or posterior margins, frozen section biopsy should also be performed. When frozen section biopsy confirms tumor involvement of the nipple-areola complex (NAC), superficial margin, or posterior margin, additional excision including the skin and NAC, or postoperative radiotherapy, will be considered.
| Study group | Role | What they receive |
|---|---|---|
| robot assisted nipple sparing mastectomy(RNSM) | Experimental | Robotic nipple sparing mastectomy, robotic mastectomy, hybrid robotic nipple sparing mastectomy, robotic nipple mammary complex and skin sparing mastectomy, robot nipple sparing mastectomy Receives: Procedure: Robot-assisted Nipple-Sparing Mastectomy (RNSM) |
| Conventional nipple sparing mastectomy(CNSM) | Active comparator | Total mastectomy, mastectomy, nipple sparing mastectomy, skin sparing mastectomy, nipple sparing breast resection, open nipple sparing mastectomy, general nipple sparing Mammastectomy, an open-window nipple sparing mastectomy Receives: Procedure: Conventional nipple sparing mastectomy(CNSM) |
What is being measured
The primary outcome is the main question the study is designed to answer.
5-year disease-free survival rate(DFS)
From the date of surgery to the first qualifying event, or censored at the date of last follow-up if no event occurs
- Events: local/regional/distant recurrence, contralateral breast cancer, or all-cause mortality.
- Local recurrence: recurrence in the ipsilateral breast or chest muscles, ipsilateral chest wall, or nipple-areola complex (NAC).
- Regional recurrence: recurrence in the ipsilateral axillary lymph nodes, ipsilateral infra/supraclavicular lymph nodes, or ipsilateral internal mammary lymph nodes.
- intraepithelial carcinoma is included as an event for local recurrence and contralateral breast cancer.
- patients without an event are censored at the last known disease assessment.
Statistical analysis (non-inferiority)
- DFS will be analyzed using a Cox proportional hazards model stratified by institution and clinical stage.
- The hazard ratio (HR) for RNSM vs CNSM and its 95% confidence interval (CI) will be estimated.
Measured: The DFS period is calculated from the date of surgery to the time of the first event, or censored at the date of last follow-up if no event is reported.
Secondary outcomes (15)
5-Year Overall Survival (OS)
Events for OS are defined as death from any cause. OS time will be calculated in months from the date of surgery to the date of the event.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Breast Cancer-Specific Survival (BCSS)
Events for BCSS include death attributable to breast cancer. Deaths from unrelated causes will be censored.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Distant Recurrence-Free Survival (DRFS)
Events for DRFS are defined as the first occurrence of distant recurrence. Local recurrence and contralateral breast cancer will be censored.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Locoregional Recurrence-Free Survival (LRFS)
Events for LRFS include the first occurrence of local or regional recurrence. Distant recurrence and contralateral breast cancer will be censored.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Nipple Recurrence Rate (NR)
NR is defined as the first recurrence of the nipple-areola complex (NAC). Recurrence in the ipsilateral breast or chest muscles, chest wall, regional lymph nodes, contralateral breast, or distant sites will be censored.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Positive Margin Rate (at Surgery)
A positive margin is defined as tumor involvement of the NAC, superficial, posterior, or circumferential margins confirmed in the final pathology report. The overall positive margin rate will be analyzed.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Conversion Rate to Open Surgery (RNSM Group Only; at Surgery)
In the RNSM group, intraoperative conversion from RNSM to CNSM will be analyzed. Reasons for conversion will be documented.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Operation time
Total operative time includes both mastectomy and reconstruction. Each component will be measured separately and analyzed.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
30-Day Postoperative Complication Rate
The complication rate within 30 days post-surgery will be calculated as the total number of complications per patient in each group. Both the total number of complications per patient and the number of Clavien-Dindo grade III or higher complications per patient will be analyzed. NAC necrosis rate will also be evaluated.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Clavien-Dindo Classification of Postoperative Complications (within 180 days)
Postoperative complications will be assessed using the Clavien-Dindo classification. Grade III or higher complications, including flap or implant loss, will be analyzed.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Flap or Implant Loss Rate (within 1 year postoperatively)
Measured: Flap or implant loss within 1 year of surgery will be recorded and analyzed.
Patient-Reported Outcomes (between 3 and 12 months postoperatively)
Breast satisfaction will be evaluated using the BREAST-Q version 2.0 scale administered before and after mastectomy. Higher scores indicate better outcomes.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Surgeon Satisfaction (between 3 and 12 months postoperatively)
Surgical satisfaction will be evaluated by the operating surgeon. Overall symmetry, postoperative scarring, and NAC symmetry will be scored using a 0-10 scale, with higher scores indicating better outcomes.
Overall symmetry, postoperative scar, and NAC symmetry are measured using scoring system 0-10. The higher scores are, the better an outcome is.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Cost-Effectiveness (between 3 and 12 months postoperatively; optional)
Cost-effectiveness will be assessed between 3 and 12 months after the final surgery using the Korean version of the EuroQol 5-Dimension (EQ-5D) questionnaire. Higher scores indicate better outcomes across all dimensions.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
30-Day Estimated Postoperative Complication Rate
Based on a sample size of 790 (632 after accounting for 20% dropout), the study has at least 80% power to detect various assumed complication rates between the conventional and robotic groups, with a non-inferiority margin of 7.5%. The assumed 30-day complication rate for the conventional group is 25-50%. The maximum 30-day complication rate for the robotic group to be considered non-inferior is presented in Table 2. These will be analyzed as secondary endpoints.
Measured: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2022
- Study start26 Oct 2022
- Primary completionJun 2032 (estimated)
- Study completionJun 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast Cancer Classified as TNM Stage 0-IIIaStudies of the same condition, open and under way.
- More trials run by Yonsei UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- RNSM and CNSM procedures are systematic at 1:1 ratio after obtaining consent forms for research participation and checking criteria for exclusion from selection It is randomly assigned from the award. The patient is subjected to a single blind examination so that the surgical method is unknown before surgery. Reconstruction methods after resection are discussed with breast and/or plastic surgeons
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 790 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yonsei University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hyung Seok Park, MD, PhD, Principal investigator, Yonsei University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05490433
- Sponsor's protocol ID
- 4-2022-0600
- Acronym
- ROM
- Status last verified
- Nov 2025
- First submitted
- 3 Aug 2022
- Last updated
- 17 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Multicenter Randomized Clinical Trial: Robot-assisted vs. Open Nipple-sparing Mastectomy With Immediate Breast Reconstruction (ROM) Trial
- ClinicalTrials.gov ID
- NCT05490433
- Acronym / sponsor ID
- ROM / 4-2022-0600
- Keywords
- Breast cancer
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 790 participants (estimated)
- Lead sponsor
- Yonsei UniversityUniversity, hospital or other
- Study start
- 26 Oct 2022 (actual)
- Primary completion
- Jun 2032 (estimated)
- Study completion
- Jun 2032 (estimated)
- First posted
- 5 Aug 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- RNSM and CNSM procedures are systematic at 1:1 ratio after obtaining consent forms for research participation and checking criteria for exclusion from selection It is randomly assigned from the award. The patient is subjected to a single blind examination so that the surgical method is unknown before surgery. Reconstruction methods after resection are discussed with breast and/or plastic surgeons
| Arm | Type | Receives |
|---|---|---|
| robot assisted nipple sparing mastectomy(RNSM) | Experimental | Procedure: Robot-assisted Nipple-Sparing Mastectomy (RNSM)Robotic nipple sparing mastectomy, robotic mastectomy, hybrid robotic nipple sparing mastectomy, robotic nipple mammary complex and skin sparing mastectomy, robot nipple sparing mastectomy |
| Conventional nipple sparing mastectomy(CNSM) | Active comparator | Procedure: Conventional nipple sparing mastectomy(CNSM)Total mastectomy, mastectomy, nipple sparing mastectomy, skin sparing mastectomy, nipple sparing breast resection, open nipple sparing mastectomy, general nipple sparing Mammastectomy, an open-window nipple sparing mastectomy |
Who may qualify
- Ages
- 19 to 70 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (17 listed)
- Patients scheduled for breast-conserving surgery or deemed ineligible for immediate breast reconstruction (IBR).
- Clinical evidence of nipple or skin involvement on preoperative evaluation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Robot-assisted Nipple-Sparing Mastectomy (RNSM)Patients undergoing robot-assisted nipple-sparing mastectomy (RNSM) with immediate breast reconstruction (IBR) will be enrolled in this group. RNSM will be performed using robotic surgical platforms, including the da Vinci S, Si, X, Xi, and SP systems. The procedure will be conducted through an axillary or lateral chest wall incision. During surgery, posterior areolar tissue sampling for frozen section biopsy will be recommended. If suspicious lesions are detected at the superficial or posterior margins, frozen section biopsy of those lesions will also be performed. When tumor involvement of the nipple-areola complex (NAC), superficial margin, or posterior margin is confirmed by frozen section biopsy, additional resection including the skin and NAC, or postoperative radiotherapy, will be considered. | Procedure or surgery | robot assisted nipple sparing mastectomy(RNSM) |
| Conventional nipple sparing mastectomy(CNSM)Patients who undergo conventional nipple-sparing mastectomy (CNSM) with immediate breast reconstruction (IBR) will be enrolled in this group. CNSM is performed without the use of robotic or endoscopic surgical systems, and all types of skin incisions are permitted. During surgery, posterior areolar tissue sampling for frozen section biopsy is recommended. If suspicious lesions suggesting tumor involvement are identified at the superficial or posterior margins, frozen section biopsy should also be performed. When frozen section biopsy confirms tumor involvement of the nipple-areola complex (NAC), superficial margin, or posterior margin, additional excision including the skin and NAC, or postoperative radiotherapy, will be considered. | Procedure or surgery | Conventional nipple sparing mastectomy(CNSM) |
Primary outcome
5-year disease-free survival rate(DFS)
Time frame: The DFS period is calculated from the date of surgery to the time of the first event, or censored at the date of last follow-up if no event is reported.
From the date of surgery to the first qualifying event, or censored at the date of last follow-up if no event occurs * Events: local/regional/distant recurrence, contralateral breast cancer, or all-cause mortality. * Local recurrence: recurrence in the ipsilateral breast or chest muscles, ipsilateral chest wall, or nipple-areola complex (NAC). * Regional recurrence: recurrence in the ipsilateral axillary lymph nodes, ipsilateral infra/supraclavicular lymph nodes, or ipsilateral internal mammary lymph nodes. * intraepithelial carcinoma is included as an event for local recurrence and contralateral breast cancer. * patients without an event are censored at the last known disease assessment. Statistical analysis (non-inferiority) * DFS will be analyzed using a Cox proportional hazards model stratified by institution and clinical stage. * The hazard ratio (HR) for RNSM vs CNSM and its 95% confidence interval (CI) will be estimated.
15 secondary outcomes
5-Year Overall Survival (OS)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Breast Cancer-Specific Survival (BCSS)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Distant Recurrence-Free Survival (DRFS)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Locoregional Recurrence-Free Survival (LRFS)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
5-Year Nipple Recurrence Rate (NR)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Positive Margin Rate (at Surgery)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Conversion Rate to Open Surgery (RNSM Group Only; at Surgery)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Operation time
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
30-Day Postoperative Complication Rate
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Clavien-Dindo Classification of Postoperative Complications (within 180 days)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Flap or Implant Loss Rate (within 1 year postoperatively)
Time frame: Flap or implant loss within 1 year of surgery will be recorded and analyzed.
Patient-Reported Outcomes (between 3 and 12 months postoperatively)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Surgeon Satisfaction (between 3 and 12 months postoperatively)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Cost-Effectiveness (between 3 and 12 months postoperatively; optional)
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
30-Day Estimated Postoperative Complication Rate
Time frame: secondary outcome is calculated from the date of surgery to the time the first event occurs, or if the event is not reported on the last follow-up date.(After 5 years of follow-up observation of subject registration)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Nov 2025.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Hyung Seok Park, MD, PhD principal investigator
Yonsei University
17 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Robot-assisted Nipple-Sparing Mastectomy (RNSM) and Conventional nipple sparing mastectomy(CNSM) in people with Breast Cancer Classified as TNM Stage 0-IIIa, run by Yonsei University at 17 sites in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 17 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 17 sites in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Hyung Seok Park, MD, PhD (82-10-6760-2974, imgenius@yuhs.ac), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
5-year disease-free survival rate(DFS) (time frame: The DFS period is calculated from the date of surgery to the time of the first event, or censored at the date of last follow-up if no event is reported.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Nov 2025.