A Study to Evaluate Circulating Tumor DNA (ctDNA) and Immunophenotyping as Potential Biomarkers in Patients Undergoing Regional Nodal Irradiation for Breast Cancer


About this study

The purpose of this study is to estimate the circulating tumor DNA (ctDNA)detection rate and mutational load in breast cancer patients with indications for regional nodal irradiation.

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.

Inclusion Criteria:

  • Histologically confirmed primary or recurrent invasive breast cancer with plans for adjuvant radiation therapy at the Mayo Clinic.
  • Oligometastatic breast cancer (≤ 3 sites of metastases) is permitted provided that the disease is managed with curative intent.
  • Patients treated with lumpectomy or mastectomy.
  • Patients must have indication for regional nodal irradiation.
  • Age 18 or older.
  • Willingness to provide informed consent and expresses understanding of this protocol and its requirements, risks, and discomforts.
  • Patients must have completed their final breast surgery including re-excision of margins for invasive cancer and DCIS or chemotherapy within 90 days prior to registration but no sooner than 21 days prior to the initiation of radiation therapy (RT).
  • Bilateral breast cancer is permitted.
  • Positive or close margins is allowed.

Exclusion Criteria: 

  • Other active malignancy ≤ 2 years prior to registration (exceptions: non-melanotic skin cancer or carcinoma-in-situ of the cervix).
  • Pregnancy or lactation.
  • Inability on the part of the patient to understand the informed consent to be compliant with the protocol.


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

Robert Mutter, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

More information


Publications are currently not available

Mayo Clinic Footer