Abstract OT2-03-01: NRG oncology/NSABP B-51/RTOG 1304: A phase III superiority clinical trial designed to determine if chest wall and regional nodal radiotherapy (CWRNRT) post mastectomy (Mx) or the addition of RNRT to breast RT post breast-conserving surgery (BCS) will reduce invasive cancer events in patients (pts) with positive axillary (Ax) nodes and convert to ypN0 after neoadjuvant chemotherapy (NC)

Background:This phase III post-NC trial evaluates if CWRNRT post Mx or whole breast irradiation (WBI) with RNRT after BCS significantly reduces the invasive breast cancer recurrence-free interval (IBC-RFI) rate in pts presenting with positive Ax nodes that are pathologically negative after NC. Secondary aims are OS, LRRFI, DRFI, DFS-DCIS, and second primary cancer, as well as comparing RT effect on cosmesis in reconstructed Mx pts.Correlative science studies examine RT effect by tumor subtype, molecular outcome predictors for residual disease pts, and predictors for the degree of reduction in loco-regional recurrence.Methods:Clinical T1-3, N1 IBC pts with positive Ax nodes (FNA or core needle biopsy) complete ≥8 wks of NC (anthracycline and/or taxane). HER2-positive pts receive anti-HER2 therapy (tx). After NC, BCS or Mx is performed with a sentinel node biopsy (≥2 nodes) and/or Ax dissection with histologically negative nodes. ER/PR and HER2 neu status before NC is required. Pts receive required systemic tx. Radiation credentialing with a facility questionnaire and a case benchmark is required. Randomization for Mx pts is to no CWRNRT or CWRNRT and for BCS pts to WBI or WBI+RNRT.Statistics:1636 pts to be enrolled over 5 yrs with definitive analysis at 7.5 yrs. Study is powered at 80% to test that RT reduces the annual hazard rate of events for IBCR-FI by 35% for an absolute risk reduction in the 5-yr cumulative rate of 4.6%. Intent-to-treat analysis with 3 interim analys...
Source: Cancer Research - Category: Cancer & Oncology Authors: Tags: Ongoing Clinical Trials Source Type: research