Pre-surgery hormone therapy to lower positive margins in lobular breast cancer

Impact of Neoadjuvant Endocrine Therapy on Surgical Outcomes in Patients With Stage 2 to 3 Invasive Lobular Carcinoma: A Prospective Study

Phase 2 Interventional Memorial Sloan Kettering Cancer Center · NCT07483307

This Phase 2 trial tests whether giving endocrine (hormone) therapy before breast-conserving surgery can reduce the chance of cancer at the edges of the removed tissue in postmenopausal people with ER+/HER2- invasive lobular breast cancer.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment176 (estimated)
Ages50 Years and up
SexFemale
SponsorMemorial Sloan Kettering Cancer Center Academic / other
Drugs / interventionschemotherapy
Locations7 sites (Basking Ridge, New Jersey and 6 other locations)
Trial IDNCT07483307 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional study gives neoadjuvant endocrine therapy (NET) to postmenopausal adults with biopsy-proven ER+/HER2- invasive lobular carcinoma who plan to undergo breast-conserving surgery. Participants receive NET prior to surgery and then proceed to excision, with the primary outcome being the presence or absence of cancer at the surgical margins on pathology. Secondary assessments include imaging and surgical outcomes to determine whether NET facilitates more complete resections and reduces the need for re-excision. Patients with advanced nodal disease, prior ipsilateral breast cancer, or contraindications to MRI are excluded.

Who should consider this trial

Good fit: Ideal candidates are postmenopausal adults age 50 or older with biopsy-confirmed cT2–T3, N0–N1 ER+/HER2- invasive lobular carcinoma who choose and are medically fit for breast-conserving surgery.

Not a fit: Patients with prior cancer in the same breast, advanced regional (cN2/cN3) or metastatic disease, those judged to need neoadjuvant chemotherapy, or those who cannot undergo surgery or MRI are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the approach could lower the rate of positive margins and reduce the need for repeat surgeries, helping more patients preserve their breasts.

How similar studies have performed: Neoadjuvant endocrine therapy has produced tumor shrinkage and enabled breast conservation in some ER+ cancers, but responses in the lobular subtype have been less consistent and this specific application is relatively understudied.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Written informed consent by participant or legally authorized representative
* Postmenopausal women aged ≥50 years with biopsy-proven cT2-T3 N0-1 ILC who opt to undergo and are medically fit to undergo BCS at enrollment.
* Tumors of the ER+/HER2- subtype, defined as:

  1. ER+: Positive for ER staining as indicated by ≥10% immunoreactive tumor nuclei.
  2. HER2-: Immunohistochemistry assay demonstrating no or faint staining in ≤10% of tumor cells (IHC 0 or 1+) or negative by dual probe in situ hybridization assay.

Exclusion Criteria:

* Patients with prior ipsilateral breast cancer.
* Patients with advanced regional disease (cN2/cN3) or stage 4 disease.
* Patients who would benefit from neoadjuvant chemotherapy, per the treating medical oncologist.
* Patients who are not candidates for definitive breast surgery (inoperable or stage 4 disease).
* Patients with gadolinium allergy, precluding the use of breast MRI.

Where this trial is running

Basking Ridge, New Jersey and 6 other locations

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.
Conditions Breast CancerHER2-negative Breast CancerHER2 Negative Breast CarcinomaER+ Breast Cancer26-095Memorial Sloan Kettering Cancer Center
Last reviewed 2026-06-13 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.