A Phase 3 interventional study of Ovarian Function Suppression + Aromatase Inhibitor and Adjuvant Chemotherapy + Ovarian Function Suppression in Breast Cancer, sponsored by NRG Oncology. Recruiting at 1,276 sites in 9 countries. Open to female participants aged 18 Years to 60 Years. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by NRG Oncology · Phase 3, Interventional, and Treatment
This Phase III Trial will determine whether adjuvant chemotherapy (ACT) added to ovarian function suppression (OFS) plus endocrine therapy (ET) is superior to OFS plus ET in improving invasive breast cancer-free survival (IBCFS) among premenopausal, early- stage breast cancer (EBC) patients with estrogen receptor (ER)-positive, HER2-negative tumors and 21-gene recurrence score (RS) between 16-25 (for pN0 patients) and 0-25 (for pN1 patients).
Younger age at diagnosis is an adverse prognostic factor in early breast cancer: women who are less than 35 years of age at diagnosis are more likely to die from their disease than their older counterparts following standard treatments. There remains a pressing need for advancements in therapeutic options for this patient population. One increasingly utilized option is ovarian suppression, which was first reported as treatment for advanced breast cancer in 1896 and has been examined in a multitude of clinical trials over the past century. As chemotherapeutic options became more commonplace for breast cancer therapy, however, the role of ovarian suppression became uncertain.
In the pre-genomic era, several studies evaluated the role of ovarian suppression compared to chemotherapy, with conflicting results. These studies either looked at ovarian suppression alone or at tamoxifen compared to chemotherapy. A meta-analysis examining LHRH-agonists (luteinizing hormone-releasing hormone) in the Early Breast Cancer Overview group (LHRH-agonists in Early Breast Cancer Overview group 2007) showed that when LHRH-agonists were added to tamoxifen, chemotherapy, or both, there was a 12.7% reduction in the risk of recurrence and a 15.1% reduction in the risk of death. When compared to chemotherapy, LHRH-agonists appeared to be equally as effective, especially if patients were less than 40 years of age. These older studies, conducted in the pre-taxane/anthracycline era, typically used CMF (cyclophosphamide, methotrexate, and fluorouracil) chemotherapy, and were designed prior to the use of genomic assays .
14,825 studies on the registry are indexed under Breast Neoplasms; 3,319 are open to participants now.
This study's planned enrollment of 3,960 is above the median of 72 across 10,896 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →NRG Oncology is the lead sponsor of 72 studies on the registry; 25 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
A patient cannot be considered eligible for this study unless ALL of the following conditions are met.
Oncotype DX RS must be less than 26.
* Patients with a "Low Risk" or "MP1" MammaPrint (a genomic test that analyzes the activity of certain genes in early-stage breast cancer) result must have eligibility assessed with an Oncotype DX RS at pre-entry (see Section 3.1). Blocks or unstained slides must be sent to the Genomic Health centralized laboratory for testing at no cost to these patients. If MammaPrint High Risk or MP2, these patients are not eligible.
Exclusion Criteria:
Definitive clinical or radiologic evidence of disease.
Known results from most recent lab studies obtained as part of routine care prior to study entry showing ANY of the following values:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Karnofsky performance status (KPS)
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HER2
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Aromatase inhibitor co-administered with a GnRH agonist (gonadotropin releasing hormone) for 5 years. The choice of AI is per investigator discretion. The choice of GnRH agonist and dosing schedule is per investigator's discretion. Options commonly include goserelin, leuprolide, or triptorelin given monthly or every-three-months. The dose and schedule of AI should be consistent with the drug package insert. Endocrine treatment beyond 5 years is at the investigator's discretion. Bilateral oophorectomy may substitute for ovarian suppression if desired.
Drug: Ovarian Function Suppression + Aromatase Inhibitor
Adjuvant chemotherapy of investigator's choice followed by an aromatase inhibitor (AI) co-administered with an GnRH agonist for 5 years. The choice of AI is per investigator discretion. The choice of GnRH agonist and dosing schedule is per investigator's discretion. Options commonly include goserelin, leuprolide, or triptorelin given monthly or every-three-months. The dose and schedule of AI should be consistent with the drug package insert. Endocrine treatment beyond 5 years is at the investigator's discretion. Bilateral oophorectomy may substitute for ovarian suppression if desired.
Drug: Ovarian Function Suppression + Aromatase Inhibitor · Drug: Adjuvant Chemotherapy + Ovarian Function Suppression
Aromatase inhibitor co-administered with a GnRH agonist for 5 years. The choice of AI is per investigator discretion. The choice of GnRH agonist and dosing schedule is per investigator's discretion. Options commonly include goserelin, leuprolide, or triptorelin given monthly or every-three-months. The dose and schedule of AI should be consistent with the drug package insert. Endocrine treatment beyond 5 years is at the investigator's discretion. Bilateral oophorectomy may substitute for ovarian suppression if desired.
Adjuvant chemotherapy of investigator's choice followed by an aromatase inhibitor (AI) co-administered with an GnRH agonist for 5 years. The choice of AI is per investigator discretion. The choice of GnRH agonist and dosing schedule is per investigator's discretion. Options commonly include goserelin, leuprolide, or triptorelin given monthly or every-three-months. The dose and schedule of AI should be consistent with the drug package insert. Endocrine treatment beyond 5 years is at the investigator's discretion. Bilateral oophorectomy may substitute for ovarian suppression if desired.
Invasive breast cancer-free survival (IBCFS)
Time from randomization to the first diagnosis of local invasive recurrence following mastectomy, local invasive recurrence in the ipsilateral breast following lumpectomy, regional recurrence, distant recurrence, contralateral invasive breast cancer, or death from any cause prior to recurrence or contralateral breast cancer.
Time frame: Time from randomization for duration of trial, 11 years
Invasive disease-free survival (IDFS)
Time from randomization to the first diagnosis of local invasive recurrence following mastectomy, local invasive recurrence in the ipsilateral breast following lumpectomy, regional recurrence, distant recurrence, contralateral invasive breast cancer, second non-breast primary cancer (excluding squamous or basal cell carcinoma of the skin), or death from any cause prior to recurrence or second primary cancer.
Time frame: Time from randomization for duration of trial, 11 years
Overall survival
Time from randomization to death from any cause
Time frame: Time from randomization for duration of trial, 11 years
Distant recurrence-free interval (DRFI)
Time from randomization until the first diagnosis of distant metastasis or death from breast cancer, regardless of occurrence of any intervening local or regional recurrences, contralateral breast cancers, or non-breast second primary cancers. This endpoint is censored at the time of death from causes other than breast cancer.
Time frame: Time from randomization for duration of trial, 11 years
Breast cancer-free interval (BCFI)
Time from randomization until the first diagnosis of local invasive recurrence, regional recurrence, distant recurrence, contralateral breast cancer or death from breast cancer.
Time frame: Time from randomization for duration of trial, 11 years
Menopausal symptoms measured by the FACT ESS-19 score
The FACT-ES 19 Item Endocrine Symptom Subscale (ESS-19) score. The score is calculated as a sum of 19 endocrine symptom items. The score range is 0-76 and a higher score indicates better QOL.
Time frame: Measured at one year after randomization
Pain during aromatase inhibitor (AI) therapy
The pain severity question from the PROMIS-29 Profile. Pain will be measured on a 0-10 scale using the pain questions from the PROMIS-29 profile.
Time frame: Measured at one year after randomization
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Plan to share: Yes — NCI is committed to sharing data in accordance with NIH policy. For more details on how clinical trial data is shared, access the link to the NIH data sharing policy page.
Data sharing details ↗ · grants.nih.gov
No publications or documents are linked to this record.
Started Oct 2023 (actual). Primary completion is estimated for Jan 2032, 99 months after the start.
Of 328 non-industry phase 3 interventional studies under Breast Neoplasms, half reached primary completion within 79 months of starting (the median), counting those still running; a quarter within 50 and three quarters within 127. This study's planned 99 months is above that.
Counting every sponsor, half of 600 studies reached it within 59 months; a quarter within 36 and three quarters within 96.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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NRG Oncology