Comparison of Adjuvant Endocrine Therapy and Accelerated Partial Breast Irradiation following Lumpectomy for the Treatment of Early-Stage Breast Cancer Patients Over 65, CAMERAN Study

PRIMARY OBJECTIVE:

I. To compare quality of life at 1 year after breast conserving surgery in those who receive adjuvant accelerated partial breast irradiation alone versus adjuvant endocrine therapy alone as measured by the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (EORTC QLQ-C30) and Quality of Life Questionnaire - Breast Cancer (QLQ-BR45).

SECONDARY OBJECTIVES:

I. To assess the 2-year outcome of disease-free survival, including ductal carcinoma in situ (DCIS) (disease free survival [DFS]-DCIS), in subjects who have received accelerated partial breast irradiation alone versus endocrine therapy alone after breast conserving surgery.

II. To assess the 2-year overall survival (OS) in subjects who have received accelerated partial breast irradiation alone versus endocrine therapy alone after breast conserving surgery.

EXPLORATORY OBJECTIVES:

I. To measure the adherence to the planned endocrine therapy in the endocrine therapy alone arm using a medication usage questionnaire that has been developed at University of North Carolina (UNC) and utilized prospectively. This questionnaire was developed to understand both extent of endocrine therapy (ET) use and reason-specific underuse to measure medication adherence.

II. To assess 5-year DFS-DCIS in subjects who have received accelerated partial breast irradiation alone versus endocrine therapy alone after breast conserving surgery.

III. To assess 5-year OS in subjects who receive accelerated partial breast irradiation alone versus endocrine therapy alone after breast conserving surgery.

IV. To measure patient-level knowledge of clinical trials to evaluate if patient-level knowledge changes after they participate in a clinical trial.

V. To measure patient-level attitudes towards clinical trials to understand if patient-level attitudes change after patient participation in a cancer clinical trial.

VI. To measure patient-reported financial toxicity according to Functional Assessment of Chronic Illness Therapy's (FACIT’s) Comprehensive Score for Financial Toxicity (COST) as there are various costs associated with not only cancer care but also cancer clinical trial participation.

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM A: Patients receive adjuvant endocrine therapy daily for 5 years as per standard of care at the discretion of the treating medical oncologist.

ARM B: Within 12 weeks of surgery, patients undergo accelerated partial breast irradiation with either intensity modulated radiation therapy (IMRT) or 3-dimensional conformal radiation therapy (3D CRT) over 5 fractions every other day (excluding weekends). Patients undergo computed tomography (CT) scan on study.

After completion of study treatment, patients are followed up at 1 year, 2 years, and up to 5 years post-operatively.