Classification of rectal cancer according to recurrence types - comparison of Japanese guidelines and Western guidelines

Table 2 Distance to the lower border of the tumor according to localization by rigid endoscopy and enema examination

Classification	Rigid endoscope				Enema examination
	mean ± SD	Range	n		mean ± SD	Range	n
RS	10.3 ± 2.3	6-13.5	12 (11.8)		12.3 ± 2.8	7-21	105 (29.9)
Ra	7.7 ± 1.6	5-12	38 (37.6)		7.2 ± 2.3	3-18	90
Rb	3.5 ± 1.8	0-7	54 (53.4)		3.2 ± 2.3	0-10	156
	0-5 cm	6-10 cm	11-15 cm	> 15 cm	Total
RS	0	28 (26.6)	66 (62.8)	11 (10.4)	105
Ra	17 (18.8)	67 (74.4)	5 (4.4)	1 (1.1)	90
Rb	132 (84.6)	24 (15.3)	0	0	156

Classifications: Rb (below the peritoneal inversion), Ra (between the inferior margin of second sacral vertebrae and Rb) and RS (between Ra and sacral promontory). SD: Standard deviation.