Mismatch repair protein expression and intratumoral budding in rectal cancer are associated with an increased pathological complete response to preoperative chemoradiotherapy: A case-control study

Table 1 Clinical-pathological characteristic of 216 patients with rectal carcinoma with preoperative chemo-radiotherapy, divided by type of pathological response n (%)

	No pathological complete response group (controls) (n = 144)	Pathological complete response group (cases) (n = 72)	P
Median age (yr ± SD)	56.67 ± 11.94	57.22 ± 13.65	0.7593
Sex
Female	48 (33.3)	24 (33.3)	1.01
Male	96 (66.7)	48 (66.7)
Histologic grade
G1	30 (20.8)	27 (37.5)
G2	44 (30.6)	6 (8.3)	< 0.0011
G3	70 (48.6)	39 (54.2)	0.1471
Budding
Low (0-4 buds)	63 (43.8)	44 (61.6)	0.0161
High (5 or more buds)	81 (56.2)	28 (38.4)
Missmatch repair status
MMR proficient	112 (77.8)	41 (56.9)	0.0011
MMR defective	32 (22.2)	31 (43.1)
CDX2 expression
Absent	8 (5.6)	7 (9.7)	0.1951
Present	136 (94.4)	65 (90.3)
MLH1
Non expressed	23 (16)	26 (36.1)	0.0011
Normal	121 (84)	46 (63.9)
PMS2
Non expressed	23 (16)	26 (36.1)	0.0011
Normal	121 (84)	46 (63.6)
MSH2
Non expressed	11 (7.6)	0	0.0102
Normal	133 (92.4)	72 (100)
MSH6
Non expressed	12 (8.3)	4 (5.6)	0.5872
Normal	132 (91.7)	68 (94.4)
Lymphovascular invasion
Absent	130 (90.3)	63 (87.5)	0.1051
Present	14 (9.7)	9 (12.5)

¹Value calculated form Chi square test with the first group as the reference;

²Values calculated from Fischer’s exact test;

³Value calculated from a Student t-test. MMR: Mismatch repair system; SD: Standard deviation.