Escalated-Dose Radiotherapy for Unresected Locally Advanced Pancreatic Cancer: Patterns of Care and Survival in the United States

Authors

Christopher Shi
Brian De
Hop S Tran Cao
Suyu Liu
Marcus A Florez
Ramez Kouzy
Adam J Grippin
Matthew H G Katz
Ching-Wei D Tzeng
Naruhiko Ikoma
Michael P Kim
Sunyoung Lee
Jason Willis
Sonal S Noticewala
Bruce D Minsky
Grace L Smith
Emma B Holliday
Cullen M Taniguchi
Albert C Koong
Prajnan Das
Ethan B Ludmir
Eugene J Koay

Publication Date

6-1-2024

Journal

Cancer Medicine

Abstract

INTRODUCTION: With locally advanced pancreatic cancer (LAPC), uncontrolled local tumor growth frequently leads to mortality. Advancements in radiotherapy (RT) techniques have enabled conformal delivery of escalated-dose RT (EDR), which may have potential local control and overall survival (OS) benefits based on retrospective and early prospective studies. With evidence for EDR emerging, we characterized the adoption of EDR across the United States and its associated outcomes.

METHODS: We searched the National Cancer Database for nonsurgically managed LAPC patients diagnosed between 2004 and 2019. Pancreas-directed RT with biologically effective doses (BED10) ≥39 and ≤70 Gy was labeled conventional-dose RT (CDR), and BED10 >70 and ≤132 Gy was labeled EDR. We identified associations of EDR and OS using logistic and Cox regressions, respectively.

RESULTS: Among the definitive therapy subset (n = 54,115) of the entire study cohort (n = 91,493), the most common treatments were chemotherapy alone (69%), chemotherapy and radiation (29%), and RT alone (2%). For the radiation therapy subset (n = 16,978), use of pancreas-directed RT remained between 13% and 17% over the study period (ptrend > 0.999). Using multivariable logistic regression, treatment at an academic/research facility (adjusted odds ratio [aOR] 1.46, p < 0.001) and treatment between 2016 and 2019 (aOR 2.54, p < 0.001) were associated with greater receipt of EDR, whereas use of chemotherapy (aOR 0.60, p < 0.001) was associated with less receipt. Median OS estimates for EDR and CDR were 14.5 months and 13.0 months (p < 0.0001), respectively. For radiation therapy subset patients with available survival data (n = 13,579), multivariable Cox regression correlated EDR (adjusted hazard ratio 0.85, 95% confidence interval 0.80-0.91; p < 0.001) with longer OS versus CDR.

DISCUSSION AND CONCLUSIONS: Utilization of EDR has increased since 2016, but overall utilization of RT for LAPC has remained at less than one in five patients for almost two decades. These real-world results additionally provide an estimate of effect size of EDR for future prospective trials.

Keywords

Humans, Pancreatic Neoplasms, Male, Female, United States, Aged, Middle Aged, Radiotherapy Dosage, Retrospective Studies, Aged, 80 and over, adenocarcinoma, chemoradiotherapy, definitive therapy, dose escalation

Comments

Supplementary Materials

PMID: 38923407