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.