Determinants of magnetic resonance imaging overstaging in rectal cancer T-staging

Table 1 Univariate analysis of factors affecting magnetic resonance imaging T-staging accuracy, n (%)

Variable	Cases	Understaging	χ2	P value	Overstaging	χ2	P value
Gender
Male	216	11 (5.1)	0.857	0.355	72 (33.3)	1.194	0.275
Female	133	10 (7.5)			52 (39.1)
Age (year)
< 60	123	6 (4.9)	0.436	0.509	39 (31.7)	1.212	0.271
≥ 60	226	15 (6.6)			85 (37.6)
BMI (kg/m2)
< 24	213	12 (5.6)	0.142	0.706	74 (34.7)	0.148	0.7
≥ 24	136	9 (6.6)			50 (36.8)
Distance from anal verge
≤ 5	174	7 (4.0)	4.16	0.1131	66 (37.9)	3.592	0.166
5-10 cm	138	13 (9.4)			50 (36.2)
≥ 10 cm	37	1 (2.7)			8 (21.6)
Maximum tumor diameter
< 4 cm	174	7 (4.0)	2.44	0.118	78 (44.8)	13.095	< 0.001
≥ 4 cm	175	14 (8.0)			46 (26.3)
Circumferential involvement
≤ 1/4	61	4 (6.6)	4.507	0.1951	30 (49.2)	18.69	< 0.001
> 1/4 - ≤ 1/2	149	8 (5.4)			60 (40.3)
> 1/2 - ≤ 3/4	77	2 (2.6)			25 (32.5)
> 3/4 - 1	62	7 (11.3)			9 (14.5)
Tumor location
Anterior	120	12 (10.0)	5.307	0.1351	39 (32.5)	4.096	0.255
Right	65	2 (3.1)			29 (44.6)
Posterior	99	3 (3.0)			37 (37.4)
Left	65	4 (6.2)			19 (29.2)
Neoadjuvant chemoradiotherapy
None	273	18 (6.6)	1.814	0.3781	89 (32.6)	6.34	0.04
Chemotherapy only	51	1 (2.0)			26 (51.0)
Chemoradiotherapy	25	2 (8.0)			9 (36.0)
Pathological type
Polyp carcinogenesis	59	1 (1.7)	1.516	0.2181	36 (61.0)	20.135	< 0.001
Primary carcinoma	290	20 (6.9)			88 (30.3)

¹Fisher’s exact test.

BMI: Body mass index.