Comparing OSNA and ultrastaging to find sentinel lymph node metastases in endometrial cancer

One Step Nucleic Acid Amplification (OSNA) Versus Ultrastaging to Detect Sentinel Lymph Node Metastasis in Endometrial Cancer: a Randomized, Multicenter, Controlled Trial (SENT-OSNA Study)

NA · Fondazione Policlinico Universitario Agostino Gemelli IRCCS · NCT06935305

This study tests whether the OSNA molecular test finds sentinel lymph node metastases as well as standard ultrastaging in people having surgery for early-stage endometrial cancer.

Quick facts

PhaseNA
Study typeInterventional
Enrollment1922 (estimated)
SexFemale
SponsorFondazione Policlinico Universitario Agostino Gemelli IRCCS (other)
Locations1 site (Rome, Italy)
Trial IDNCT06935305 on ClinicalTrials.gov

What this trial studies

This is a randomized non-inferiority trial that assigns patients before surgery to either standard histopathologic ultrastaging or the OSNA molecular assay to detect metastases in sentinel lymph nodes. The primary endpoint is the proportion of randomized patients with at least one positive sentinel lymph node, with a planned sample size of 1,922 patients and two interim analyses using an O'Brien–Fleming alpha spending approach. Secondary analyses include classification of isolated tumor cells, micro- and macrometastases and quantification of CK19 mRNA copy number to estimate metastasis volume. Analyses will report proportions with 95% confidence intervals and summarize baseline variables using medians and interquartile ranges.

Who should consider this trial

Good fit: Adults with histologically confirmed endometrial cancer who appear to have FIGO stage I–II disease and are scheduled for radical surgery with an attempt at sentinel lymph node mapping are eligible.

Not a fit: Patients with uterine sarcoma, dedifferentiated or undifferentiated histologies, prior pelvic nodal surgery, neoadjuvant therapy, very large preoperative lymph nodes, or those not undergoing SLN mapping are unlikely to benefit from this trial.

Why it matters

Potential benefit: If successful, OSNA could provide equally reliable and faster intraoperative detection of sentinel node metastases, potentially reducing the need for additional procedures.

How similar studies have performed: Smaller studies and experience in other cancers suggest OSNA can perform comparably to ultrastaging, but large randomized evidence specifically in endometrial cancer is limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Histologically confirmed endometrial cancer
* Apparent (pre-operative) FIGO stage I-II
* Radical surgery
* Attempt of SLN mapping

Exclusion Criteria:

* Uterine sarcoma (including endometrial stromal sarcoma)
* Fertility sparing surgery
* Dedifferentiated histology
* Undifferentiated histology
* Neoadjuvant therapy
* Previous surgery to pelvic lymph nodes
* Lymph nodes with short axis \>15 mm at pre-operative imaging

Where this trial is running

Rome, Italy

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Endometrial Cancer, endometrial cancer, OSNA, sentinel lymph node, ultrastaging

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.