Pilot Trial of Preop Partial Radiation in Breast Cancer Patients

Overview

The purpose of our study is to assess the feasibility of preoperative partial breast (APBI) radiation in breast cancer patients. The primary outcome is the acute wound complication rate. We also aim to evaluate cosmetic outcomes and late toxicities as secondary objectives. Another goal is to examine the histopathology of tumors before and after radiation to assess the response and other immunologic and/or molecular changes to the tumor and its environment elicited by the radiation treatment. We hope that this will guide future trials that could change practice in specific patient subgroups.

Our primary objective is to demonstrate that the incidence of grade 3 or more wound complications in patients with non-metastatic and clinically node negative breast cancer or DCIS who are eligible for BCS and treated with pre-operative partial breast irradiation (PBI) at 1 month is no worse than the rates in the current standard of care (6-20%). Our secondary objective is to demonstrate that the physician reported cosmetic outcome at 1 and 3 years after the end of treatment is better than what has been reported for the current standard of practice for patients undergoing BCS and hypofractionated WBI (around 35% reported poor/fair cosmesis at 3 years, Shaitelman et al.). Tertiary objectives are to measure acute and late radiation-related toxicities, such as radiation dermatitis, telangiectasia, and fibrosis, in this cohort of patients and to measure biologic markers that radiation may influence. To measure the pre-operative APBI clinical target volume (CTV) and compare it to the post-op APBI CTV volume that would have been contoured as CTV if the partial breast was to be delivered post-operatively. To measure the incidence of fair/poor patient-reported cosmetic outcomes using the BCTOS cosmetic scale. To study cancer biology before and after radiation treatment.