Multi-institutional Study to Increase Breast Conserving Surgery (BCS) Rate With Personalized Neoadjuvant Strategy in ER Positive and HER2 Negative Breast Cancer Patients for Whom BCS is Not Feasible

  • End date
    Dec 31, 2028
  • participants needed
  • sponsor
    Seoul National University Hospital
Updated on 27 October 2022
endocrine therapy
hormone therapy
breast-conserving surgery
her2/neu-negative breast cancer


In ER+ and HER2- breast cancer(BC) patients for whom BCS is not feasible, we investigate the rate of BCS can be increased while decreasing unnecessary chemotherapy thru selective neoadjuvant chemotherapy or neoadjuvant endocrine therapy using tools of nodal status, Ki-67, and multigene assay(Mammaprint)


In patients with resectable BC, the neoadjuvant chemotherapy is recognized as one of the standard therapy in order to control and prevent the micrometastasis.

Conducting neoadjuvant chemotherapy can lead to increased numbers of BCS compared with adjuvant chemotherapy and the prognosis of BC patients is known to be improved when there is pathological complete response (pCR) after neoadjuvant chemotherapy compared with no pCR.

The effect of neoadjuvant chemotherapy is different in breast cancer subtypes. The quasi-pCR in HR- HER2+ BC is reported as 67% while 37% and 13% in triple negative and HR+ HER2- BC, respectively and it indicates that neoadjuvant chemotherapy has only limited effect in HR+ BC and the declined quality of life and the fecundity loss due to chemotherapy is a serious socioeconomic loss, especially in young patients.

According to the SOFT trial, for high risk, pre-menopausal women, use of exmestane (AI, Aromatase Inhibitors) and ovarian suppression as adjuvant systemic therapy did improve the PFD compared with the use of tamoxifen and ovarian suppression.

Neoadjuvant hormonal therapy as well as neoadjuvant chemotherapy has benefits in making inoperable BC to operable BC and improving the possibility of BCS by reducing the tumor size with complete response or partial response. Although these neoadjuvant systemic therapies have an ultimate objective to reduce the recurrence rate and improve the survival rate, the overall survival and disease-free survival has been reported similar to adjuvant systemic therapies. The clinical response rate of neoadjuvant hormonal therapy ranged from 13.5% to 100%, the radiologic response rate by ultrasound ranged from 20% to 91.7%, and these are statistically similar to the response rate of the neoadjuvant chemotherapy in ER+ patients. Most studies where letrozole was tested among AIs showed that letrozole has a similar or a little better effect on clinical or radiological response rate over tamoxifen and there were statistically more patients who became operable or eligible for BCS after neoadjuvant chemotherapy. Comparison studies among AIs showed that the response rates have been best achieved in letrozole over anastrozole and exemestane and the BCS rate was lowest in letrozole without statistical significance. According to the standard treatment guideline suggesting the selective use of ovarian suppression along with tamoxifen in HR+, premenopausal patients, a study investigated the combined treatment of letrozole with reversible ovarian ablation using goserelin (luteinizing hormone-releasing hormone: LHRH). The results showed that the response rate of the combination treatment of goserelin and anastrozole for 24 weeks as neoadjuvant hormonal therapy was statistically superior to goserelin and tamoxifen in premenopausal BC patients and this was not observed in the adjuvant setting. The most commonly used agents in BC are goserelin and leuprorelin(Leuplin) and their mechanism of action is to desensitize the hypothalamus and suppress the ovarian function by reducing the secretion of LH and FSH.

MammaPrint, which analyses 70-gene expressed in breast cancer, can identify low risk patients who may safely forgo chemotherapy and high risk patients who can benefit from chemotherapy. Recent results from MINDACT trial have proved that 46.2% of HR+ and clinical high risk patients were classified into MammaPrint low risk and they could avoid unnecessary chemotherapy. In 2017 San Antonio breast cancer symposium, Dubsky et al. reported the analysis of correlation between neoadjuvant chemotherapy and score of Endopredict(EP) multigene assay in ER+ and HER2- patients treated on ABCSG 34. In neoadjuvant chemotherapy group, reduction of tumor size in patients with low EP score(Endopredict low risk group) was significantly low(NPV 100%). Meanwhile, in neoadjuvant hormonal therapy group, reduction of tumor size in patients with high EP score(Endopredict high risk group) was significantly low(NPV 92%). These results support the evidence that response of neoadjuvant chemotherapy or hormonal therapy can be predicted by the molecular score of tumor and selective treatment can maximize the effect.

Accordingly, in this study, patients with MammaPrint test is performed, neoadjuvant chemotherapy is conducted to genomic High Risk patients, and neoadjuvant endocrine therapy is conducted to Low Risk patients. Although adjuvant therapy is conducted after the completion of this study, in case there is progressive disease (PD) after neoadjuvant endocrine therapy, adjuvant chemotherapy is conducted.

Condition Breast Cancer
Treatment Letrozole, MammaPrint, Leuprorelin acetate
Clinical Study IdentifierNCT03900637
SponsorSeoul National University Hospital
Last Modified on27 October 2022


Yes No Not Sure

Inclusion Criteria

Histopathologically and immunohistochemically confirmed ER+ and HER2- BC patients
Stage I-IIIA BC patients with detectable tumor sizes
BC patients for whom BCS is not feasible due to tumor sizes or locations (two surgeons at each institution evaluate the infeasibility of BCS)
Patients without distant metastasis which were identified pathologically or radiologically
Female patients ≥ 19 years
Diagnosis of menopause is defined as no menstruation for 1-year or both ovaries removed surgically
ECOG 0-2
Patients with adequate bone marrow function
Hemoglobin 10 g/dL, ANC 1,500/mm3, Plt 100,000/mm3
Patients with adequate kidney function
serum Cr ≤ 1.5 mg/dL
Patients with adequate liver function
Bilirubin: ≤ 1.5 times of upper normal limit
AST/ALT: ≤ 1.5 times of upper normal limit
Alkaline phosphatase: ≤ 1.5 times of upper normal limit
Patients who decided to voluntarily participate in this trial with written informed

Exclusion Criteria

History of treatment for ipsilateral BC or breast carcinoma in situ
Confirmed distant metastasis of BC
History of cancer other than BC
Pregnant (positive pregnancy test within a week of enrollment) or breast-feeding patients
Uncontrolled severe infection
Psychiatric illness or epilepsy
Male BC patients
Inability to understand and willingness to sign a written informed consent
Mammographic extensive microcalcification
Multicentral, Bilateral BC
History of chemotherapy or endocrine therapy on contralateral BC for the past 2 years
Undetectable and unmeasurable primary tumor size
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer  to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact


Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note