Survival benefits and disparities in radiation therapy for elderly patients with pancreatic ductal adenocarcinoma

Table 2 Logistic regression model of factors associated with receiving radiation in elderly patients with pancreatic ductal adenocarcinoma between 2004 and 2018 from Surveillance, Epidemiology, and End Results database

Variables	Subgroups	Odds ratio (95%CI)	P value
Age (yr)	65-80	Reference
	> 80	0.84 (0.74-0.97)	0.014
Year of diagnosis	2004-2010	Reference
	2011-2018	0.47 (0.42-0.52)	< 0.001
Sex	Female	Reference
	Male	1.01 (0.91-1.11)	0.909
Race	White	Reference
	Black	1.1(0.93-1.3)	0.25
	Other	0.90 (0.77-1.05)	0.19
Marital status	Married	Reference
	Unmarried	0.92 (0.83-1.03)	0.144
Primary site	Head	Reference
	Body/tail	0.87 (0.77-0.99)	0.032
	Other	0.85 (0.73-0.98)	0.031
Histology grade	Grade I-II	Reference
	Grade III-IV	0.95(0.82-1.11)	0.55
	Unknow	1(0.87-1.16)	0.948
Node status	Negative	Reference
	Positive	0.99 (0.89-1.11)	0.864
Tumor size (cm)	< 2	Reference
	2-4	1.24 (1.04-1.48)	0.016
	> 4	1.23 (1.02-1.48)	0.033
SEER stage	Localized	Reference
	Regional	1.01 (0.86-1.19)	0.891
	Distant	0.17 (0.14-0.21)	< 0.001
Surgery	No	Reference
	Yes	1.02 (0.88-1.17)	0.804
Chemotherapy	No	Reference
	Yes	7.05 (6.14-8.1)	< 0.001

SEER: Surveillance, Epidemiology, and End Results; CI: Confidence interval.