Proton radiotherapy as a treatment strategy to increase survival in locally advanced pancreatic cancer in the body and tail: a retrospective study

Table 3 Univariate and multivariate analyses of prognostic factors for overall survival (n = 200)

Variables	Univariate		Multivariate
Variables	HR (95% CI)	P value	HR (95% CI)	P value
Age ≧ 65 years	1.06 (0.65–1.73)	0.822
Gender, Male	0.97 (0.71–1.32)	0.836
Body mass index < 18.5 kg/m²	1.43 (1.01–2.01)	0.044	1.17 (0.81–1.68)	0.403
ECOG-PS, 1–2	1.04 (0.75–1.46)	0.811
CA19-9 ≧ 231.9 U/mL	1.86 (1.35–2.55)	< 0.001	1.75 (1.27–2.43)	0.001
CEA ≧ 3.5 ng/mL	1.39 (1.02–1.91)	0.040	1.12 (0.81–1.55)	0.502
Previous treatment, Yes	1.26 (0.92–1.73)	0.149
Major arterial invasion
SMA only versus CA only	1.61 (1.03–2.50)	0.036	1.62 (1.00–2.62)	0.049
SMA and CA versus CA only	1.56 (1.10–2.22)	0.014	1.56 (1.08–2.25)	0.017
Tumor size ≧ 40 mm	1.01 (0.73–1.37)	0.963
Bile duct invasion, positive	1.24 (0.81–1.91)	0.322
Duodenal invasion, positive	1.44 (0.85–2.44)	0.170
Anterior peripancreatic invasion, positive	1.49 (1.07–2.09)	0.020	1.65 (1.15–2.43)	0.006
Venous invasion, positive	1.25 (0.70–2.20)	0.450
Other organ invasion, positive	1.15(0.47–2.82)	0.755
UICC N, 1 and 2	0.94 (0.67–1.32)	0.742
Complete scheduled concurrent chemotherapy, No	1.66 (1.17–2.34)	0.004	1.63 (1.13–2.35)	0.009
Acute toxicities CTCAE grade ≧ 3	1.20 (0.87–1.65)	0.259
Late toxicities CTCAE grade ≧ 3	1.43 (0.81–2.53)	0.220
GTV V60 GyE ≧ 60%	0.98 (0.71–1.35)	0.911

HR hazard ratio, CI confidence interval, ECOG-PS Eastern Cooperative Oncology Group-Performance Status, CEA carcinoembryonic antigen, CA19-9 carbohydrate antigen 19–9, SMA superior mesenteric artery, CA coeliac artery, UICC Union for International Cancer Control, TNM tumor-node-metastasis classification 8th edition, CTCAE common terminology criteria for adverse events, GTV gross tumor volume, GyE Gy equivalents, V60GyE the volume ratio irradiated over 60 GyE
Significant P values (< 0.05) are in bold

ISSN: 1748-717X