An observational study in Breast Cancer, sponsored by Clinica Universidad de Navarra, Universidad de Navarra. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-27.
Sponsored by Clinica Universidad de Navarra, Universidad de Navarra · Observational
Prospective study will establish a comprehensive international registry specifically for patients who have undergone surgery for primary breast cancer without SLNB. The main objective of this registry is to gather detailed, real-world data on the outcomes of this particular treatment approach, providing insights into the clinical efficacy and quality of life of patients when SLNB is omitted.
All patients with histologically confirmed invasive breast cancer and a negative axillary US who are candidates for omitting SLN biopsy or any axillary surgery will be informed about the possible participation in the study. The inclusion and exclusion criteria are verified by the investigator and written informed consent is obtained from the patient. Surgical treatment, pathological assessment and postoperative locoregional and systemic therapy should be conducted according to institutional and national standards. Since the OXYGENATE study in a non-interventional trial, the study sites do not deviate from their own institutional protocol at any timepoint. The follow up on patient status is conducted yearly during the first 5 years after surgery.
12,544 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.
This study's planned enrollment of 827 is above the median of 184 across 2,642 observational studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Clinica Universidad de Navarra, Universidad de Navarra is the lead sponsor of 158 studies on the registry; 36 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Early stage breast cancer patients with omission of SLN
Inclusion Criteria:
Older than 18 years old cT1-2 cN0 Negative preoperative assessment of the axilla Breast surgery as first treatment No axillary surgery Multifocal/ multicentric breast cancer Candidates to receive breast conserving surgery Written informed consent must be signed and dated by the patient and the investigator prior to inclusion.
Patients must be accessible for follow-up.
Exclusion Criteria Synchronous distant metastases Any axillary surgery Neoadjuvant treatment Previous malignancy Bilateral breast cancer Previous primary systemic therapy Pregnancy or breastfeeding Pre-operative diagnosis (cytology or histology) of axillary lymph node metastases Pre-operative radiological evidence of multiple involved or suspicious nodes Patients with psychiatric, addictive, or any disorder, which compromises their ability to give informed consent for participation in this study.
Procedure: Omission SLN
Omission SLN
Axillary Recurrence
Determine the clinical efficacy of omitting a SLN i
Time frame: from enrollement to the end of follow up 5 years
3 year axillary recurrence
Identify if patients with no axillary surgery had an increased axillary recurrence
Time frame: 3 years
No study locations are listed for this record.
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes
Supporting information: Study protocol, Sap, Icf
This study is not yet recruiting, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Clinica Universidad de Navarra, Universidad de Navarra