Title
A Phase III Clinical Trial Evaluating De-Escalation of Breast Radiation for Conservative Treatment of Stage I, Hormone Sensitive, HER2-Negative, Oncotype Recurrence Score

Description
This Phase III Trial evaluates whether breast conservation surgery and endocrine therapy results in a non-inferior rate of invasive or non-invasive ipsilateral breast tumor recurrence (IBTR) compared to breast conservation with breast radiation and endocrine therapy.

Objective
Primary Objective:

To evaluate whether breast conservation surgery and endocrine therapy results in a non-inferior rate of invasive or non-invasive ipsilateral breast tumor recurrence (IBTR) compared to breast conservation with breast radiation and endocrine therapy.

To evaluate whether breast conservation surgery and endocrine therapy inclusive of any second breast conservation surgery for salvage of IBTR results in a non-inferior rate of overall breast conservation compared to breast conserving surgery, endocrine therapy and radiation for IBTR.

To evaluate whether breast conservation surgery and endocrine therapy results in a non-inferior rate of invasive ipsilateral breast tumor recurrence (IIBTR) compared to breast conservation, breast radiation, and endocrine therapy.

To evaluate whether breast conservation surgery and endocrine therapy results in a non-inferior relapse free interval (RFI) compared to breast conservation, breast radiation, and endocrine therapy.

To evaluate whether breast conservation surgery and endocrine therapy results in a non-inferior distant disease-free survival(DDFS) compared to breast conservation, breast radiation, and endocrine therapy.

To evaluate whether breast conservation surgery and endocrine therapy results in a non-inferior overall survival (OS) compared to breast conservation, breast radiation, and endocrine therapy.

To evaluate whether there is a difference in patient-reported breast pain in women who do and do not receive breast radiation.

To evaluate whether there is a difference in patient-reported worry about recurrence in women who do and do not receive breast radiation.

To evaluate whether adherence to endocrine therapy following breast conservation surgery alone is non inferior compared to endocrine therapy with breast conservation surgery and breast radiation.

Treatment Active Comparator: Arm 1: Breast Radiation Therapy + Endocrine Therapy -
Radiation therapy to the breast and hormonal drug for at least 5 years. Tamoxifen 20 mg daily Anastrozole 1 mg daily Letrozole 2.5 mg daily Exemestane 25 mg daily

Active Comparator: Arm 2: No Breast Radiation Therapy + Endocrine Therapy -
No radiation therapy, only hormonal drug for at least 5 years. Tamoxifen 20 mg daily Anastrozole 1 mg daily Letrozole 2.5 mg daily Exemestane 25 mg daily

Key Eligibility For full study eligibility, please see this study's ClinicialTrails.gov record.

Applicable Disease Sites
Breast

Participating Institutions
DN Greenwald Center; Johnson Creek, UW Cancer Center; Oconomowoc Memorial Hospital, Waukesha Memorial; UW Cancer Center at ProHealth; UW Health Carbone Cancer Center Rockford; UW Health Eastpark Medical Center; UW Health University Hospital; Waukesha Memorial Hosp