The influence of radiation therapy dose escalation on overall survival in unresectable pancreatic adenocarcinoma.
OBJECTIVE
Radiation therapy (RT) dose escalation in unresectable pancreatic adenocarcinoma (PAC) remains investigational. We examined the association between total RT dose and overall survival (OS) in patients with unresectable PAC.


METHODS
National cancer data base (NCDB) data were obtained for patients who underwent definitive chemotherapy and RT (chemo-RT) for unresectable PAC. Univariate (UV) and multivariate (MV) survival analysis were performed along with Kaplan-Meier (KM) estimates for incremental RT dose levels.


RESULTS
A total of 977 analyzable patients met inclusion criteria. Median tumor size was 4.0 cm (0.3-40 cm) and median RT dose was 45 Gy. Median OS was 10 months (95% CI, 9-10 months). On MV analysis RT dose <30 Gy [HR, 2.38 (95% CI, 1.85-3.07); P<0.001] and RT dose ≥30 to <40 Gy [HR, 1.41 (95% CI, 1.04-1.91); P=0.026] were associated with lower OS when compared with dose ≥55 Gy. Patients receiving RT doses from 40 to <45, 45 to <50, 50 to <55, and ≥55 Gy did not differ in OS.


CONCLUSIONS
Lack of benefit to OS with conventionally delivered RT above 40 Gy is shown. Optimal RT dose escalation methods in unresectable PAC remain an important subject for investigation in prospective clinical trials.
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
William A
WA
Hall
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Lauren E
LE
Colbert
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Dana
D
Nickleach
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Jeffrey
J
Switchenko
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Yuan
Y
Liu
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Theresa
T
Gillespie
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Joseph
J
Lipscomb
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Claire
C
Hardy
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
David A
DA
Kooby
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Roshan S
RS
Prabhu
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
John
J
Kauh
1 Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 2 Biostatistics & Bioinformatics Shared Resource at Winship Cancer Institute, Atlanta, GA, USA ; 3 Department of Surgery and Winship Cancer Institute, Emory University, Atlanta, GA, USA ; 4 Atlanta Veterans Affairs Medical Center, Atlanta, GA, USA ; 5 Rollins School of Public Health and Winship Cancer Institute, Atlanta, GA, USA ; 6 Department of Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA.
Jerome C
JC
Landry
PAC and intensity modulated radiation therapy (IMRT); PAC and radiation therapy (RT); RT dose in unresectable pancreatic cancer; Radiation dose escalation pancreatic cancer; dose response pancreatic cancer; radiation dose escalation in pancreatic adenocarcinoma (PAC); unresectable pancreatic cancer