NCT05879926 · NRG Oncology
Evaluating the Addition of Adjuvant Chemotherapy to Ovarian Function Suppression Plus Endocrine Therapy in Premenopausal Patients With pN0-1, ER-Positive/HER2-Negative Breast Cancer and an Oncotype Recurrence Score Less Than or Equal to 25
(OFSET)
What this study is about
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).
View original scientific description
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).
Interventions
DRUG
Ovarian Function Suppression + Aromatase Inhibitor
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.
DRUG
Adjuvant Chemotherapy + Ovarian Function Suppression
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.
Primary outcome measures
Invasive breast cancer-free survival (IBCFS)
Time frame: Time from randomization for duration of trial, 11 years
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- A patient cannot be considered eligible for this study unless ALL of the following conditions are met.
- The patient or a legally authorized representative must provide study-specific informed consent prior to pre-entry and, for patients treated in the U.S., authorization permitting release of personal health information.
- Female patients must be greater than or equal to 18 years of age.
- Patients must be premenopausal (evidence of functioning ovaries) at the time of pre-entry. For study purposes, premenopausal is defined as:
- Age 50 years or under with spontaneous menses within 12 months; or
- Age greater than 50-60 years with spontaneous menses within 12 months plus follicle-stimulating hormone (FSH) and estradiol levels in the premenopausal range; or
- Patients with amenorrhea due to IUD or prior uterine ablation must have FSH and estradiol levels in the premenopausal range; or
- Patients with prior hysterectomy must have FSH and estradiol le
Where
- Birmingham, Alabama
- Anchorage, Alaska
- Fairbanks, Alaska
- Kingman, Arizona
- Phoenix, Arizona
- Fort Smith, Arkansas
- Jonesboro, Arkansas
- Little Rock, Arkansas
- Anaheim, California
- Antioch, California
- Arroyo Grande, California
- Auburn, California
And 792 more locations — see the full list below.
Collaborators
National Cancer Institute (NCI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 2, 2026 · Source of record for eligibility and locations