A Study of Tamoxifen Citrate for Treating Patients with Metastatic or Recurrent Breast Cancer


About this study

The purpose of this studyis to assess how well tamoxifen citrate works in patients with metastatic or recurrent breast cancer. Estrogen can cause the growth of breast cancer cells. Hormone therapy using tamoxifen citrate may fight cancer by blocking the use of estrogen by tumor cells.


Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Eligibility Criteria

  • Disease Characteristics
    • Histologically confirmed adenocarcinoma of the breast
      • Stage III (locally advanced), metastatic, or recurrent disease
      • Deemed not resectable
    • Estrogen-receptor and/or progesterone-receptor positive disease
      • Receptor status is based on most recent results
      • Receptor testing on metastatic disease is not required
    • Measurable or non-measurable disease
    • History of CNS metastasis allowed provided it has been treated (surgery, radiotherapy, or radiosurgery) within the past 4 weeks and does not require medications to control symptoms
      • No known leptomeningeal disease allowed
  • Patient Characteristics
    • ECOG performance status 0-2
    • Menopausal status not specified
    • Total bilirubin ≤ 1.5 times upper limit of normal (ULN)
    • ALT and AST ≤ 2.5 times ULN (≤ 5 times ULN if liver metastases present)
    • Not pregnant or nursing
    • Negative pregnancy test
    • Fertile patients must use effective nonhormonal contraception
    • No medical or psychiatric conditions that would interfere with protocol compliance, the ability to provide informed consent, assessment of response, or anticipated toxicities
    • More than 5 years since prior invasive malignancies except curatively treated basal cell or squamous cell carcinoma of the skin or carcinoma in situ of the cervix
  • Prior Concurrent Therapy
    • See Disease Characteristics
    • No prior investigational agents in the metastatic setting
    • Other prior investigational agents in any setting must have been completed at least 6 weeks prior to study registration and should be discussed with the study PI
    • Prior tamoxifen as adjuvant treatment is allowed as long as the patient did not have disease relapse or progression while on adjuvant tamoxifen or within 4 weeks of last dose
      • Prior tamoxifen for advanced disease is not allowed
      • No prior chemotherapy or trastuzumab (Herceptin) for metastatic disease
    • Prior chemotherapy, trastuzumab, or bevacizumab in the adjuvant setting allowed provided it has been completed ≥ 4 weeks before study therapy
    • Must not have had more than 2 lines of non-hormonal treatment in the locally advanced or metastatic setting, including trastuzumab (Herceptin), bevacizumab, or other biologics
    • Treatment in the advanced setting must have been completed at least 2 weeks prior to study initiation
    • Prior aromatase inhibitors (e.g., anastrozole, letrozole, exemestane, aminoglutethamide) are allowed in the adjuvant or metastatic setting
    • At least 2 weeks since prior and no concurrent medications that are strong to moderate inhibitors of CYP2D6 and may alter tamoxifen citrate metabolism including, but not limited to
      • Paroxetine (Paxil)
      • Fluoxetine (Prozac)
      • Bupropion (Wellbutrin)
      • Quinidine (Cardioquin)
    • May not initiate bisphosphonate therapy while receiving treatment on this study
      • If have begun receiving bisphosphonate therapy prior to registration may continue at the same intervals used prior to study registration
    • Concurrent radiotherapy to painful sites of bone disease or areas of impending fractures allowed provided the following criteria are met:
      • Radiotherapy was initiated before study entry
      • Sites of measurable or non-measurable disease are outside the radiotherapy port
      • Recovered from prior radiotherapy
    • No other concurrent hormonal therapy
    • No concurrent chemotherapy

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Matthew Goetz, M.D.

Closed for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

More information


Publications are currently not available

Additional contact information

Cancer-related trials contact form

Phone: 855-776-0015 (toll-free)

International patient clinical studies questions