Predictors of durable no evidence of disease status in de novo metastatic inflammatory breast cancer patients treated with neoadjuvant chemotherapy and post-mastectomy radiation.
BACKGROUND
Definitive locoregional therapy including surgery and post-mastectomy radiation therapy (PMRT) has been offered to select IBC patients with de novo metastatic disease. Herein we examined predictive factors for progression-free survival after comprehensive PMRT radiation +/- locoregional treatment of metastatic sites.


METHODS
Charts of T4d, any N, M1 (de novo) patients who completed PMRT to ≥ 50 Gy from 2006-2011 were reviewed. Patients who received doses <50Gy to the primary site, received radiation at another facility or were treated pre-operatively were excluded. The remaining 36 patients formed the study cohort. Progression-free survival post-PMRT (PFSx) was assessed from the last day of radiation. Median dose to primary fields was 51 Gy. Boost doses ranged from 6-16 Gy.


RESULTS
Median age at diagnosis was 54 (range 33-70). Median follow up from primary irradiation completion was 31 months. Sixteen patients were Stage IV NED at last follow-up (IR 37-60 mo). Fifteen patients died of disease. Five patients experienced an in-field recurrence, three of which resulted from local recurrence at the medial edge of the field. Actuarial 5 year locoregional control (LRC) was 86%. Median PFSx was 20 months. All sites of gross disease were treated with radiation in 21/36 patients. Location of metastatic disease had no correlation with PFSx. Estrogen receptor (ER)- patients had shorter 5-yr actuarial PFSx (28% vs. 66%, P = 0.03) and 5 year actuarial OSx (37% vs 71%, P = 0.02). Nine patients (25%) developed a pathological complete response (pCR) after chemotherapy and with a median follow-up of 59 months, 7 remained without evidence of disease.


CONCLUSIONS
Despite the poor prognosis associated with metastatic IBC, our data suggest that select patients may be appropriate candidates for locoregional therapy. Patients who achieve a pCR or those with ER + disease have a favorable PFSx. It remains unclear whether all gross disease needs to be addressed with locoregional therapy to provide benefit.
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Vinita
V
Takiar
Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Catherine L
CL
Akay
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Michael C
MC
Stauder
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Welela
W
Tereffe
Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Ricardo H
RH
Alvarez
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Karen E
KE
Hoffman
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
George H
GH
Perkins
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Eric A
EA
Strom
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Thomas A
TA
Buchholz
Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Naoto T
NT
Ueno
Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX USA.
Gildy
G
Babiera
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, TX USA ; Department of Radiation Oncology-Unit 97, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030 USA.
Wendy A
WA
Woodward
Inflammatory breast cancer; Metastatic disease; Pathologic complete response; Post-mastectomy; Radiation therapy