Potential risk factors

Table 1. Factors reported to be associated or not associated with anastomotic and/or intraluminal recurrence risk specifically. Note that a factor may be present in both categories. Risk factors are shown for rectal and colon cancer separately, if reported accordingly.

	Potential risk factor for anastomotic and/or intraluminal recurrence	Factors not associated with anastomotic and/or intraluminal recurrence risk
Tumor size, nodal involvement	Rectal: tumor >5-6 cm^1,2, T3-T4^2,3, N2²	Rectal: T and N stage^4,5Colon: T and N stage²
Histology	CRC: mucinous type^1,2Colon: PNI+², LVI+^2,6Rectal ca: LVI+⁵	CRC: histological grade^2,3,5,7Rectal: LVI+^2,4,6, PNI+^3,4
Resection margin	Rectal: distal margin <8 mm⁵, distal margin involvement³	Rectal: clear distal margin <10 mm^2-4,8circumferential margin size^3,4Colon: clear distal margin <10 mm²
Surgical technique	Rectal: no intraoperative rectal washout^9,10	Rectal: no intraoperative rectal washout^2,11use of stapler^11,12minimally invasive approach²
Adjuvant treatment	Rectal: neoadjuvant treatment^4,13,14	Rectal: neoadjuvant treatement^2,3adjuvant treatment^2,3,5Colon: adjuvant treatment¹
Perioperative complications		CRC: emergency surgery, bowel perforation, obstruction, anastomotic leakage^1,2
Other factors	Colon: age¹Rectum: preoperative CEA level²CRC: preoperative CEA level¹	Rectal: age^1,2,4CRC: sex¹

CRC, colorectal cancer; LVI, lymphovascular invasion; PNI, perineural invasion; CEA, carcinoembryonic antigen.