Beyond the tumor region: Peritumoral radiomics enhances prognostic accuracy in locally advanced rectal cancer

Table 2 Univariate and multivariate analyses of clinicoradiological characteristics in the training set

Variable	Training	Univariate analysis		Multivariate analysis
		3-year PFS (%)	1P value	HR (95%CI)2	2P value
Age (years)	273		0.518
Sex			0.424
Male	184	86.23
Female	89	83.09
BMI			0.013a
< 18.5	31	67.59		1 (Ref.)
18.5-24	112	86.39		0.44 (0.20-0.98)	0.045a
> 24	130	88.40		0.40 (0.18-0.91)	0.029a
CEA level (ng/mL)			0.312
< 5	151	87.38
≥ 5	122	82.51
CA199 level (U/mL)			0.112
< 35	186	87.54
≥ 35	87	80.19
NCRT regimen
Capecitabine + RT	114	83.32	0.667
CapeOx + RT	155	86.89
Other	4	75.00
Adjuvant chemotherapy			0.936
No	69	85.31
Yes	204	85.19
Clinical T stage			0.698
cT2	20	90.00
cT3	167	83.10
cT4	86	88.24
Clinical N stage			0.776
cN0	45	88.72
cN1	125	84.66
cN2	63	84.04
cNx	40	84.71
Overall clinical stage			0.323
II	45	88.72
III	228	84.52
Tumor location (cm)			0.535
≤ 5	111	85.40
5.1-10	148	84.36
> 10	14	92.86
Circumferential tumor extent			0.810
1/4-2/4	37	86.15
3/4	68	86.74
4/4	168	84.37
MRF status			0.011a
Negative	123	90.12		1 (Ref.)
Positive	150	81.19		1.71 (0.86-3.42)	0.129a
EMVI			0.667
Negative	191	85.75
Positive	82	84.00
ypT stage			0.005a
ypT0-2	150	89.88		1 (Ref.)
ypT3-4	123	79.53		1.25 (0.59-2.63)	0.561
ypN stage			< 0.001a
ypN0	231	88.62		1 (Ref.)
ypN1	36	69.44		2.45 (1.18-5.07)	0.016a
ypN2	6	50.00		3.88 (1.28-11.79)	0.017a
TRG			0.006a
1-2	140	89.87		1 (Ref.)
3-5	133	80.30		1.71 (0.83–3.53)	0.145

¹P prediction of OS calculated according to the log-rank test.

²P HR and P value calculated using multivariate Cox regression analysis.

^aP < 0.05.

BMI: Body mass index; CA199: Carbohydrate antigen 199; CapeOx: Capecitabine plus oxaliplatin; CEA: Carcinoembryonic antigen; EMVI: Extramural vascular invasion; MRF: Mesorectal fascia; NCRT: Neoadjuvant chemoradiotherapy; RT: Radiotherapy; TRG: Tumor regression grade; ypT stage: Pathological T stage after neoadjuvant chemoradiotherapy; ypN stage: Pathological N stage after neoadjuvant chemoradiotherapy; PFS: Progression-free survival; HR: Hazard ratio; CI: Confidence interval.