Prognostic value of preoperative enhanced computed tomography as a quantitative imaging biomarker in pancreatic cancer

Table 5 Univariate analysis using Cox regression for postoperative overall survival in all patients

Variable	No. of patients, n (%)	No. of events	Median OS (mo) (95%CI)	P value
Age (yr)				0.699
≤ 60	31 (46.3)	27	14.6 (9.1-20.0)
> 60	36 (53.7)	30	10.2 (5.7-14.7)
Sex				0.651
Male	42 (62.7)	34	10.2 (4.3-16.1)
Female	25 (37.3)	23	13.6 (9.2-18.1)
Tumour location				0.836
Head/uncinate	44 (65.7)	36	12.0 (7.7-16.3)
Body/tail	23 (34.3)	21	12.8 (4.1-21.6)
AJCC stage (2017)				0.005
I	11 (16.4)	6	27.3 (14.9-39.6)
II	27 (40.3)	23	12.0 (10.2-13.8)
III	29 (43.3)	28	8.9 (5.0-12.7)
CA19-9				0.033
< 37 ng/mL	20 (29.9)	14	15.8 (10.4-21.2)
≥ 37 ng/mL	47 (70.1)	43	11.3 (7.2-15.3)
Tumour differentiation				0.255
Highly/moderately	49 (73.1)	42	14.7 (11.9-17.6)
Poorly/undifferentiated	18 (26.9)	15	8.2 (5.7-10.7)
Surgical margin				0.141
Negative	57 (85.1)	47	12.3 (7.5-17.1)
Positive	10 (14.9)	10	12.0 (2.9-21.1)
Vascular invasion				0.435
No	51 (76.1)	41	12.3 (7.7-16.9)
Yes	16 (23.9)	16	12.0 (4.8-19.2)
Adjuvant chemotherapy				0.000
No	33 (49.3)	32	8.2 (6.6-9.7)
Yes	34 (50.7)	25	17.7 (14.4-20.9)
TRER				0.001
≤ 0.7	44 (65.7)	42	10.0 (5.9-14.1)
> 0.7	23 (34.3)	15	22.0 (12.4-31.6)

CI: Confidence interval; CA19-9: Carbohydrate antigen 19-9; AJCC: American Joint Committee on Cancer; TRER: Tumour relative enhancement ratio; OS: Overall survival.