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

Table 1 Patients’ characteristics

Variable	n (%)
Male	579 (60)
Female	379 (40)
Age	22-93
Median	68
Location of the tumor RC	323 (33.7)
LC	284 (29.6)
R	351 (36.6)
Neoadjuvant CRT Yes	217 (61.8)
No	134 (38.2)
Histological type wel-mod	868 (90.6)
Muc	37 (3.8)
Por or Sig	21 (2.2)
PCR	26 (2.7)
Unknown	6 (0.6)
T factor 0	37 (3.8)
1	40 (4.2)
2	83 (8.6)
3	610 (63.6)
4	188 (19.6)
N factor positive	379 (39.5)
Negative	579 (60.4)
Lymphatic invasion positive	655 (68.3)
Negative	302 (31.5)
Unknown	1 (0.1)
Venous invasion positive	647 (67.5)
Negative	310 (32.3)
Unknown	1 (0.1)
Pathological Stage 0	38 (4)
I	59 (6.1)
II	482 (50.3)
III	379 (39.5)

RC: Right sided colon; LC: Left sided colon; R: Rectum; CRT: Chemoradiotherapy; wel: well differentiated adenocarcinoma; Mod: moderated differentiated adenocarcinoma; muc: mucinous adenocarcinoma; Por: Poorly differentiated adenocarcinoma; Sig: Signet cell adenocarcinoma; PCR: Pathological complete response.

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.

Table 3 Reccurence pattern according to Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma guidelines

	Liver (%)			Lung (%)			Local (%)
	Metastasis	n	P value	Metastasis	n	P value	Metastasis	n	P value
Colon cancer	77 (12.6)	530 (87.4)		33 (5.4)	574 (94.6)		21 (3.4)	586 (96.6)
RS	8 (7.5)	97 (92.5)	0.1491	5 (4.7)	100 (94.3)	0.7737	6 (5.7)	99 (94.3)	0.2657
Ra and Rb	23 (9.3)	223 (90.7)	0.3049	26 (10.5)	220 (89.5)	0.0043	5 (17.2)	24 (82.8)	0.0002
Total		958			958			740

Table 4 Recurrence pattern according to National Comprehensive Cancer Network and American Joint Committee on Cancer guidelines

	Liver (%)			Lung (%)			Local (%)
	Metastasis	n	P value	Metastasis	n	P value	Metastasis	n	P value
Colon cancer	77 (12.6)	530 (87.4)		33 (5.4)	574 (94.6)		21 (3.4)	586 (96.6)
> 12 cm	6 (11.5)	46 (88.5)		2 (3.8)	50 (96.2)		4 (8.3)	48 (91.7)
≤ 12 cm	25 (8.3)	274 (91.4)	0.0631	29 (10.7)	270 (89.3)	0.0117	7 (8.5)	75 (91.5)	0.0467
Total		958			958			740

Table 5 Recurrence pattern according to European Society for Medical Oncology guidelines

	Liver (%)			Lung (%)			Local (%)
	Metastasis	n	P value	Metastasis	n	P value	Metastasis	n	P value
Colon cancer	77 (12.6)	530 (87.4)		33 (5.4)	574 (94.6)		21 (3.4)	586 (96.6)
> 15 cm	2 (16.6)	10 (83.4)		1 (8.3)	11(91.7)		0 (0)	12 (100)
11-15 cm	5 (6.9)	66 (93.1)	0.1714	2 (2.8)	69 (97.2)	0.3357	4 (5.7)	65 (94.3)	0.3400
≤ 10 cm	24 (8.9)	244 (91.1)	0.1752	28 (10.4)	240 (89.6)	0.0036	7(13.2)	46 (86.8)	0.0010
Total		958			958			740