Table 8.

Management of metastatic rectal cancer.

Site	NCCN a Recommendations	ESMO b Recommendations	JSCCR c Recommendations
Peritoneal	Systemic therapy If obstructed or imminent obstruction: Resection or diverting ostomy or bypass or stenting (for upper rectal lesions only)	Complete cytoreductive surgery and HIPEC in appropriate cases. Cytoreductive surgery is particularly effective in patients with low-volume peritoneal disease (PCI < 12) and no evidence of systemic disease	Peritoneal metastases: - Complete resection is strongly recommended for P1. - Complete resection is recommended for P2 when easily resectable.
Liver Lung	Resectable: Neoadjuvant therapy, followed by staged or synchronous resection Unresectable: Chemotherapy +/− immunotherapy or targeted therapy +/− SCRT or CRT to convert to resectable	Resectable liver disease: -Upfront surgical resection +/− adjuvant FOLFOX (or CAPOX) or -Perioperative FOLFOX Unresectable liver disease: - conversion therapy i.e., systemic therapy to convert to resectable disease -local ablative techniques Lung only: -ablative techniques if resection is limited by comorbidity, the extent of lung parenchyma resection or other factors Oligometastatic disease (OMD): - Treatment strategies based on the possibility of achieving complete removal using surgical resection and/or local ablative treatment (LAT) - For patients with OMD, systemic therapy is the standard of care and should be considered as the initial part of every treatment strategy	Liver metastases: -If resectable, liver metastases should be resected upon confirming the radicality of the primary resection. - Simultaneous resection of the primary lesion and liver metastases can be safely performed. - Depending on the difficulty of hepatectomy and the general condition of the patient, metachronous resection is also performed. Lung metastases: - If resectable, resection of lung metastases should be considered after resection of the primary tumour. - Metachronous resection is generally performed to remove lung metastases after primary resection.

Adapted with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) for Guideline Rectal Cancer V.1.2022. © 2022 National Comprehensive Cancer Network, Inc. All rights reserved. The NCCN Guidelines^® and illustrations herein may not be reproduced in any form for any purpose without the express written permission of NCCN. To view the most recent and complete version of the NCCN Guidelines, go online to NCCN.org. The NCCN Guidelines are a work in progress that may be refined as often as new significant data become available. 5FU = 5-fluorouracil; RT = radiotherapy; CRT = chemoradiotherapy; SCRT = short course radiotherapy; CRM = circumferential resection margin; PCI = peritoneal carcinomatosis index; HIPEC = Hyperthermic intraperitoneal chemotherapy; P1 = metastases to the adjacent but not to the distant peritoneum; P2, a few metastases to the distant peritoneum; ^a NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) [14]; ^b European Society of Medical Oncology (ESMO) guidelines [17]; ^c Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines [18].