Once-daily radiation therapy for inflammatory breast cancer.
OBJECTIVE
Inflammatory breast cancer (IBC) is a rare and aggressive breast cancer variant treated with multimodality therapy. A variety of approaches intended to escalate the intensity and efficacy of radiation therapy have been reported, including twice-daily radiation therapy, dose escalation, and aggressive use of bolus. Herein, we examine our outcomes for patients treated with once-daily radiation therapy with aggressive bolus utilization, focusing on treatment technique.


METHODS
A retrospective review of patients with nonmetastatic IBC treated from January 1, 2000, through December 31, 2010, was performed. Locoregional control (LRC), disease-free survival (DFS), overall survival (OS) and predictors thereof were assessed.


RESULTS
Fifty-two women with IBC were identified, 49 (94%) of whom were treated with neoadjuvant chemotherapy. All underwent mastectomy followed by adjuvant radiation therapy. Radiation was delivered in once-daily fractions of 1.8 to 2.25 Gy (median, 2 Gy). Patients were typically treated with daily 1-cm bolus throughout treatment, and 33 (63%) received a subsequent boost to the mastectomy scar. Five-year Kaplan Meier survival estimates for LRC, DFS, and OS were 81%, 56%, and 64%, respectively. Locoregional recurrence was associated with poorer OS (P<.001; hazard ratio [HR], 4.1). Extracapsular extension was associated with worse LRC (P=.02), DFS (P=.007), and OS (P=.002). Age greater than 50 years was associated with better DFS (P=.03). Pathologic complete response was associated with a trend toward improved LRC (P=.06).


CONCLUSIONS
Once-daily radiation therapy with aggressive use of bolus for IBC results in outcomes consistent with previous reports using various intensified radiation therapy regimens. LRC remains a challenge despite modern systemic therapy. Extracapsular extension, age ≤50 years, and lack of complete response to chemotherapy appear to be associated with worse outcomes. Novel strategies are needed in IBC, particularly among these subsets of patients.
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Lindsay
L
Brown
Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
William
W
Harmsen
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Miran
M
Blanchard
Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota.
Matthew
M
Goetz
Department of Surgery, Mayo Clinic, Rochester, Minnesota.
James
J
Jakub
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Robert
R
Mutter
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Ivy
I
Petersen
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Jessica
J
Rooney
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Michael
M
Stauder
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Elizabeth
E
Yan
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota. Electronic address: laack.nadia@mayo.edu.
Nadia
N
Laack
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D017024:Chemotherapy, Adjuvant / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult