Usefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

Table 1 Clinicopathological characteristics of study patients

Median age (mean ± SD) (yr)	64 (61.75 ± 10.0)
M:F	1:1
Lymph node involvement prior to radiotherapy (cN)
cN0	25	62.5%
cN+	15	37.5%
Tumor stage
ypT0	1	2.5%
ypT1	4	10%
ypT2	6	15%
ypT3	29	72.5%
Lymph node status
ypN0	26	65%
ypN1	8	20%
ypN2	6	15%
Number of lymph node assessed-median (mean ± SD)	16 (18 ± 11.5)
Number of affected lymph nodes-median (mean ± SD)	0 (2.6 ± 6.9)
Tumor histological grade (G)1
G1	5	12.8%
G2	32	82.1%
G3	2	5.1%
Median tumor diameter1 (mean ± SD) (mm)	33.5 (33.7 ± 16.1)

¹One case ypT0 (2.5%) had not been taken into account.

Table 2 Relationship between “T-downstaging” and prognostic parameters

Feature	Group R (n = 11)	Group NR (n = 29)	P
Median age (range) (mean ± SD) (yr)	70 (55-77) (67.7 ± 7.2)	61 (45-70) (59.4 ± 9.9)	< 0.05
Tumor stage			< 0.000
ypT0	1 (9.1%)	0
ypT1	4 (36.4%)	0
ypT2	6 (54.6%)	0
ypT3	0	29 (100.0%)
TRG			< 0.08
1	1 (9.1%)	0
2	2 (18.2%)	1 (3.5%)
3	6 (54.6%)	11 (37.9%)
4	2 (18.2%)	14 (48.3%)
5	0	3 (10.3%)
NG			< 0.08
1	5 (45.5%)	4 (13.8%)
2	2 (18.2%)	4 (13.8%)
3	4 (36.4%)	21 (72.4%)

Table 3 Relationship between tumor stage and TRG

	TRG 1	TRG 2	TRG 3	TRG 4	TRG 5
Local tumor stage1a
ypT0	1	-	-	-	-
ypT1	-	2	2	-	-
ypT2	-	-	4	2	-
ypT3	-	1	11	14	3
Lymph nodes involvement2c
ypN0	1	3	14	8	-
ypN1	-	-	1	5	2
ypN2	-	-	2	3	1

¹Spearman R correlation r = 0.47;

^aP < 0.005, comparison between different local tumor stages.

²Spearman R correlation r = 0.47;

^cP < 0.005, comparison between different lymph nodes involvements.

Table 4 Relationship between tumor stage and NG

	NG 1	NG 2	NG 3
Local tumor stage1b
ypT0	1	-	-
ypT1	3	1	-
ypT2	1	1	4
ypT3	4	4	21
Lymph node involvement2a
ypN0	9	5	12
ypN1	-	-	8
ypN2	-	1	5

¹Spearman R correlation r = 0.42;

^bP < 0.01, comparison between different local tumor stages.

²Spearman R correlation r = 0.45;

^aP < 0.005, comparison of lymph node involvement.