Localised colon cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.

Abstract

•This ESMO Clinical Practice Guideline provides key recommendations on the management of localised colon cancer.•Authorship includes a multidisciplinary group of experts from different institutions and countries in Europe and abroad.•Diagnostic work-up is reviewed.•Key treatment recommendations are included in each section.•Follow-up indications are provided. Colorectal cancer (CRC) is the third most common tumour in men and the second in women, accounting for 10% of all tumour types worldwide. Incidence is 25% higher in males and differs greatly between countries. With more than 600 000 deaths estimated each year, CRC is the fourth most common cancer-related cause of death globally.1Arnold M. Sierra M.S. Laversanne M. et al.Global patterns and trends in colorectal cancer incidence and mortality.Gut. 2017; 66: 683-691Crossref PubMed Scopus (2671) Google Scholar,2Allemani C. Weir H.K. Carreira H. et al.Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2).Lancet. 2015; 385: 977-1010Abstract Full Text Full Text PDF PubMed Scopus (421) Google Scholar The growing incidence in some countries reflects a modification in lifestyle and its consequences related with ‘Westernisation’ such as obesity, physical inactivity, alcohol consumption, high red meat intake and cigarette smoking.3Kerr J. Anderson C. Lippman S.M. Physical activity, sedentary behaviour, diet, and cancer: an update and emerging new evidence.Lancet Oncol. 2017; 18: e457-e471Abstract Full Text Full Text PDF PubMed Scopus (315) Google Scholar Some data suggest a putative role in colon cancer carcinogenesis for factors that cause imbalances in gut microbiota.4Bullman S. Pedamallu C.S. Sicinska E. et al.Analysis of fusobacterium persistence and antibiotic response in colorectal cancer.Science. 2017; 358: 1443-1448Crossref PubMed Scopus (654) Google Scholar,5Pleguezuelos-Manzano C. Puschhof J. Rosendahl Huber A. et al.Mutational signature in colorectal cancer caused by genotoxic pks(+) E. coli.Nature. 2020; 580: 269-273Crossref PubMed Scopus (350) Google Scholar The mortality rate in the European Union is 15–20 out of 100 000 in males and 9–14 out of 100 000 in females and has decreased over time, particularly in females. In affected European individuals, 5-year survival ranges from 28.5% to 57% in men and from 30.9% to 60% in women, with a pooled estimation in 23 countries of 46.8% in men and 48.4% in women.6Torre L.A. Siegel R.L. Ward E.M. Jemal A. Global cancer incidence and mortality rates and trends–an update.Cancer Epidemiol Biomarkers Prev. 2016; 25: 16-27Crossref PubMed Scopus (2343) Google Scholar The risk of developing colon cancer depends on factors which can be classified into lifestyle or behavioural characteristics and genetically determined factors. Screening tests are modulated according to the individual probability of developing CRC.7Lauby-Secretan B. Vilahur N. Bianchini F. et al.The IARC perspective on colorectal cancer screening.N Engl J Med. 2018; 378: 1734-1740Crossref PubMed Scopus (140) Google Scholar, 8Ryan N.A.J. Morris J. Green K. et al.Association of mismatch repair mutation with age at cancer onset in Lynch syndrome: implications for stratified surveillance strategies.JAMA Oncol. 2017; 3: 1702-1706Crossref PubMed Scopus (86) Google Scholar, 9Inadomi J.M. Screening for colorectal neoplasia.N Engl J Med. 2017; 376: 149-156Crossref PubMed Scopus (69) Google Scholar Age is considered the major unchangeable risk factor for sporadic colon cancer: nearly 70% of patients are >65 years of age and this disease is rare before the age of 40 years, even though data from Western registries show an increased incidence in the 40–44-year age group.10Davis D.M. Marcet J.E. Frattini J.C. et al.Is it time to lower the recommended screening age for colorectal cancer?.J Am Coll Surg. 2011; 213: 352-361Abstract Full Text Full Text PDF PubMed Scopus (100) Google Scholar Individuals with any of the following are considered at high risk of colon cancer and must be actively screened and in case of inherited syndromes, also referred for genetic counselling (see ESMO guidelines for hereditary gastrointestinal cancer11Stjepanovic N. Moreira L. Carneiro F. et al.Hereditary gastrointestinal cancers: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.Ann Oncol. 2019; 30: 1558-1571Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar):•a medical history of adenoma, colon cancer, inflammatory bowel disease (Crohn’s disease and ulcerative colitis);•significant family history of CRC or adenoma;•an inherited cancer syndrome (2%–5% of all CRC), such as familial adenomatous polyposis coli and its variants (1%), Lynch-associated syndromes (hereditary non-polyposis colon cancer) (2%–4%), Turcot, Peutz–Jeghers and MUTYH-associated polyposis syndrome. CRC arises following progression of normal mucosa to an invasive tumour, passing through different intermediate stages of premalignant and invasive malignant lesions; this stepwise process facilitates cancer prevention and early diagnosis when the tumour is still at an early stage and curable, through screening programmes. For average-risk populations, European and American evidence-based guidelines for quality assurance in CRC screening12Atkin W.S. Valori R. Kuipers E.J. et al.European guidelines for quality assurance in colorectal cancer screening and diagnosis. First edition – colonoscopic surveillance following adenoma removal.Endoscopy. 2012; 44: E151-E163PubMed Google Scholar,13Lin J.S. Piper M.A. Perdue L.A. et al.Screening for colorectal cancer: updated evidence report and systematic review for the US preventive services task force.JAMA. 2016; 315: 2576-2594Crossref PubMed Scopus (480) Google Scholar should be followed. •Colonoscopic techniques, despite being invasive, have the advantage of being both diagnostic and therapeutic.•A complete colonoscopy is the recommended method for CRC screening in average-risk men and women based on higher sensitivity and specificity when compared with other tests14Bretthauer M. Kaminski M.F. Løberg M. et al.Population-based colonoscopy screening for colorectal cancer: a randomized clinical trial population-based colonoscopy screening for colorectal cancer.JAMA Intern Med. 2016; 176: 894-902Crossref PubMed Scopus (201) Google Scholar [II, B]. The optimal age range for testing is 50–74 years [V, C] with an optimal repetition interval for a negative test of 10 years [III, C].•Flexible sigmoidoscopy (FS) carried out every 5–10 years may be an alternative for those who refuse colonoscopy [II, B]. The combination of this method with a yearly faecal occult blood test (FOBT) (see below) is recommended to reduce the risk of a right colon tumour [III, B].•Other invasive tests including capsule colonoscopy are not recommended for screening [IV]. •Non-colonoscopic tests are recommended in average-risk men and women from the age of 50 not already taking part in colonoscopic screening programmes. The optimal frequency of testing is every year and no later than every three years [I, B]. A colonoscopy must be carried out at the earliest convenience when the test results are positive [I, A].•Among the available tests, faecal immunochemical testing (FIT) appears to be superior to high-resolution guaiac FOBT with respect to the detection rate and positive predictive value for adenomas and cancer [III]. Other novel methods including DNA-based or tests using other markers (e.g. M2-PK) lack formal comparisons of their performance, and integration with other assays needs to be monitored. Screening for high-risk populations is covered in the ESMO guidelines for hereditary gastrointestinal cancer.11Stjepanovic N. Moreira L. Carneiro F. et al.Hereditary gastrointestinal cancers: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.Ann Oncol. 2019; 30: 1558-1571Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar Colon cancer arises from the mucosa of the bowel, growing both into the lumen and the bowel wall, and/or spreading to adjacent organs. Symptoms are associated with relatively large tumours and/or advanced disease stages and may not be specific for colon cancer. Alterations in bowel habit, general or localised abdominal pain, weight loss without other specific causes, weakness, iron deficiency and anaemia are the most common symptoms and depend on the location and stage of the primary tumour.15McDermott F.T. Hughes E.S.R. Pihl E. et al.Prognosis in relation to symptom duration in colon cancer.Br J Surg. 1981; 68: 846-849Crossref PubMed Scopus (57) Google Scholar,16Ford A.C. Veldhuyzen van Zanten S.J. Rodgers C.C. et al.Diagnostic utility of alarm features for colorectal cancer: systematic review and meta-analysis.Gut. 2008; 57: 1545-1553Crossref PubMed Scopus (117) Google Scholar Colon cancer can occur with multiple or synchronous lesions (3.6%)17Lam A. Carmichael R. Buettner P.G. et al.Clinicopathological significance of synchronous carcinoma in colorectal cancer.Am J Surg. 2011; 202: 39-44Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar with identical or different histological patterns and stages of development. Metachronous primary tumours arise in up to 3% of cases during the 5 years after surgery, and the incidence increases up to 9% after several decades in long-term survivors, justifying long-term surveillance of the colon in patients who have already experienced colon cancer.18Fajobi O. Yiu C. Sen-Gupta S.B. Boulos P.B. Metachronous colorectal cancers.Br J Surg. 1998; 85: 897-901Crossref PubMed Scopus (56) Google Scholar A complete work-up should be carried out to achieve an accurate histological diagnosis of the primary tumour, assess the baseline characteristics of the patient and determine the extent of the disease (see Table 1).Table 1Diagnostic work-up for localised CRCLocal assessmentLoE, GoRComplete colonoscopyI, AImaging work-upCT scan: • LungV • AbdominalI, B • PelvicI, B CT colonography (when complete colonoscopy is not feasible)I, A MRI abdominal (to clarify ambiguous lesions or define pT4b)II, ALaboratory work-upComplete blood countII, A CoagulationII, A Liver function panelII, A Kidney function panelII, A AlbuminIII, A CEAIII, ACEA, carcinoembryonic antigen; CRC, colorectal cancer; CT, computed tomography; GoR, grade of recommendation; LoE, level of evidence; MRI, magnetic resonance imaging. Open table in a new tab CEA, carcinoembryonic antigen; CRC, colorectal cancer; CT, computed tomography; GoR, grade of recommendation; LoE, level of evidence; MRI, magnetic resonance imaging. In the absence of a bowel obstruction or massive haemorrhage, which may constitute indications of an urgent tumour resection, a total colonoscopy is recommended for diagnostic confirmation of colon cancer [I, A]. There are many advantages of endoscopy including determination and marking of the exact tumour location and biopsy of the lesion and detection and removal of (further) synchronous precancerous or cancerous lesions. Combining the limited left-sided colonoscopy with computed tomography (CT), colonoscopy is an alternative if full colonoscopy is not feasible [I, A].19Halligan S. Wooldrage K. Dadswell E. et al.Computed tomographic colonography versus barium enema for diagnosis of colorectal cancer or large polyps in symptomatic patients (SIGGAR): a multicentre randomised trial.Lancet. 2013; 381: 1185-1193Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar In cases where complete colonic exploration cannot be carried out before surgery, a complete colonoscopy should be carried out within 3–6 months [IV, B]. After colonic tumour diagnosis, clinical examination and laboratory tests must be carried out to provide a correct assessment of patient status and characteristics before deciding the definitive treatment approach [II, A]. Besides a comprehensive physical examination20Hamilton W. Round A. Sharp D. Peters T.J. Clinical features of colorectal cancer before diagnosis: a population-based case-control study.Br J Cancer. 2005; 93: 399-405Crossref PubMed Scopus (185) Google Scholar [IV], blood tests including complete blood count, coagulation, liver and kidney functions tests as well as albumin can provide relevant clinical information regarding the patient’s baseline conditions and the existence of cancer-related complications [II, A]. In addition, serum levels of carcinoembryonic antigen (CEA), although not sufficient for colon cancer diagnosis themselves in the absence of a confirmatory tumour biopsy (because of low specificity and sensitivity), should be evaluated before surgery and monitored during the follow-up period to help the early detection of metastatic disease [III, A].21Konishi T. Shimada Y. Hsu M. et al.Association of preoperative and postoperative serum carcinoembryonic antigen and colon cancer outcome.JAMA Oncol. 2018; 4: 309-315Crossref PubMed Scopus (97) Google Scholar, 22Duffy M.J. van Dalen A. Haglund C. et al.Clinical utility of biochemical markers in colorectal cancer: European Group on Tumour Markers (EGTM) guidelines.Eur J Cancer. 2003; 39: 718-727Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 23Locker G.Y. Hamilton S. Harris J. et al.ASCO 2006 update of recommendations for the use of tumor markers in gastrointestinal cancer.J Clin Oncol. 2006; 24: 531305327Crossref Scopus (1234) Google Scholar In addition, CEA level determination after colon cancer diagnosis is of particular importance since baseline levels add information in defining prognosis; a postoperative serum CEA level >5 ng/ml (or even >2.35) suggests a worse outcome.21Konishi T. Shimada Y. Hsu M. et al.Association of preoperative and postoperative serum carcinoembryonic antigen and colon cancer outcome.JAMA Oncol. 2018; 4: 309-315Crossref PubMed Scopus (97) Google Scholar Preoperative assessment of tumour extension is required to determine whether the patient should be referred for primary tumour resection or, in the presence of unresectable distant metastases, systemic therapy. Approximately 20% of newly diagnosed colon cancers have synchronous metastases, the most frequently involved organ being the liver (17%), followed by peritoneum (5%), lung (5%) and lymph nodes (3%).24van der Geest L.G. Lam-Boer J. Koopman M. et al.Nationwide trends in incidence, treatment and survival of colorectal cancer patients with synchronous metastases.Clin Exp Metastasis. 2015; 32: 457-465Crossref PubMed Scopus (297) Google Scholar CT of the thoracic, abdominal and pelvic cavities with intravenous (i.v.) contrast administration is the preferred radiological method for the evaluation of the presence of distant metastases of CRC [II, B]. This test allows evaluation of locoregional tumour extension and its complications (e.g. obstruction, perforation, fistula, abscess).25Horton K.M. Abrams R.A. Fishman E.K. Spiral CT of colon cancer: imaging features and role in management.Radiographics. 2000; 20: 419-430Crossref PubMed Scopus (140) Google Scholar Nevertheless, CT scanning may fail to detect peritoneal metastases, where sensitivity is relatively poor and depends on implant localisation and size.26Nerad E. Lahaye M.J. Maas M. et al.Diagnostic accuracy of CT for local staging of colon cancer: a systematic review and meta-analysis.AJR Am J Roentgenol. 2016; 207: 984-995Crossref PubMed Scopus (100) Google Scholar,27Koh J.L. Yan T.D. Glenn D. Morris D.L. Evaluation of preoperative computed tomography in estimating peritoneal cancer index in colorectal peritoneal carcinomatosis.Ann Surg Oncol. 2009; 16: 327-333Crossref PubMed Scopus (249) Google Scholar Contrast-enhanced magnetic resonance imaging (MRI) permits better definition of the soft tissues. It constitutes the reference test when it is necessary to evaluate the relationship of locally advanced tumours with surrounding structures or in defining ambiguous liver lesions previously detected by CT scan [II, A].28Sahani D.V. Bajwa M.A. Andrabi Y. et al.Current status of imaging and emerging techniques to evaluate liver metastases from colorectal carcinoma.Ann Surg. 2014; 259: 861-872Crossref PubMed Scopus (45) Google Scholar Likewise, MRI can substitute for CT scanning in patients with iodine-contrast allergies or chronic renal insufficiency where the glomerular filtration rate is <30 ml/min [II, A].29ACR Committee on Drugs and Contrast MediaManual on Contrast Media Version 10.3. American College of Radiology, 2018https://www.acr.org/-/media/ACR/Files/Clinical-Resources/Contrast_Media.pdfGoogle Scholar, 30van der Molen A.J. Reimer P. Dekkers I.A. et al.Post-contrast acute kidney injury – Part 1: definition, clinical features, incidence, role of contrast medium and risk factors: Recommendations for updated ESUR Contrast Medium Safety Committee guidelines.Eur Radiol. 2018; 28: 2845-2855Crossref PubMed Scopus (238) Google Scholar, 31van der Molen A.J. Reimer P. Dekkers I.A. et al.Post-contrast acute kidney injury. Part 2: risk stratification, role of hydration and other prophylactic measures, patients taking metformin and chronic dialysis patients: recommendations for updated ESUR Contrast Medium Safety Committee guidelines.Eur Radiol. 2018; 28: 2856-2869Crossref PubMed Scopus (164) Google Scholar Fluorodeoxyglucose positron emission tomography (FDG-PET), with or without integrated CT (positron emission tomography/CT), does not add significant information to the CT scans on preoperative staging of CRC and is not recommended for routine use in staging of localised CRC beyond assisting in interpretation of ambiguous findings [II, A].32Furukawa H. Ikuma H. Seki A. et al.Positron emission tomography scanning is not superior to whole body multidetector helical computed tomography in the preoperative staging of colorectal cancer.Gut. 2006; 55: 1007-1011Crossref PubMed Scopus (79) Google Scholar,33Niekel M.C. Bipat S. Stoker J. Diagnostic imaging of colorectal liver metastases with CT, MR imaging, FDG PET and/or FDG PET/CT: a meta-analysis of prospective studies including patients who have not previously undergone treatment.Radiology. 2010; 257: 674-684Crossref PubMed Scopus (405) Google Scholar •In the absence of indications for urgent tumour resection, a total colonoscopy is recommended for diagnostic confirmation of colon cancer and to rule out synchronous tumours. Combining the limited left-sided colonoscopy with CT colonoscopy is an alternative if full colonoscopy is not possible [I, A].•When not carried out before or during the surgical procedure, a complete colonoscopy should be carried out within 3–6 months following tumour resection [IV, B].•Comprehensive physical examination and laboratory tests including full blood counts, biochemistry and serum CEA levels must be carried out before decisions on the definitive treatment approach [III, A].•CT of the thoracic, abdominal and pelvic cavities with i.v. contrast administration is the preferred radiological method for the evaluation of the extent of CRC [II, B].•Contrast-enhanced MRI constitutes the reference test for evaluation of the relationship of locally advanced tumours with surrounding structures or in defining ambiguous liver lesions [II, A]. Complete en bloc endoscopic resection should be carried out whenever the morphological structure of the polyp permits.34Ferlitsch M. Moss A. Hassan C. et al.Colorectal polypectomy and endoscopic mucosal resection (EMR): European Society of Gastrointestinal Endoscopy (ESGE) clinical guideline.Endoscopy. 2017; 49: 270-297Crossref PubMed Scopus (530) Google Scholar Endoscopic resection is sufficient for hyperplastic or adenomatous polyps and non-invasive (pTis, i.e. intraepithelial or intramucosal) adenocarcinomas35Aarons C.B. Shanmugan S. Bleier J.I. Management of malignant colon polyps: current status and controversies.World J Gastroenterol. 2014; 20: 16178-16183Crossref PubMed Scopus (53) Google Scholar (see Figure 1). For (pT1) invasive carcinomas, the management is determined by the polyp morphology and the presence of histological features associated with adverse outcome36Haggitt R.C. Glotzbach R.E. Soffer E.E. Wruble L.D. Prognostic factors in colorectal carcinomas arising in adenomas: implications for lesions removed by endoscopic polypectomy.Gastroenterology. 1985; 89: 328-336Abstract Full Text PDF PubMed Scopus (589) Google Scholar:•lymphatic or venous invasion;•grade 3 differentiation;•significant (grade >1) tumour budding.37Lugli A. Kirsch R. Ajioka Y. et al.Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016.Mod Pathol. 2017; 30: 1299-1311Crossref PubMed Scopus (477) Google Scholar For a pedunculated polyp with a pT1 carcinoma confined to the head, neck and stalk (Haggitt 1–3) endoscopic resection with proper follow-up is enough even with the presence of submucosal invasion, provided that no other unfavourable factors are present [IV, B].38Backes Y. Elias S.G. Groen J.N. et al.Histologic factors associated with need for surgery in patients with pedunculated T1 colorectal carcinomas.Gastroenterology. 2018; 154: 1647-1659Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar However, the presence of any unfavourable factor in a sessile or flat polyp (Paris classification) with a pT1 carcinoma mandates surgical resection in patients with average operative risk [IV, B].39Bujanda L. Cosme A. Gil I. Arenas-Mirave J.I. Malignant colorectal polyps.World J Gastroenterol. 2010; 16: 3103-3111Crossref PubMed Scopus (115) Google Scholar The goal of surgical resection is complete lesion resection, including lymph node removal for optimal risk assessment [IV, B]. In contrast, finding positive resection margins (<1 mm) constitutes only a risk for local recurrence and can be managed by excision repetition or local surveillance.39Bujanda L. Cosme A. Gil I. Arenas-Mirave J.I. Malignant colorectal polyps.World J Gastroenterol. 2010; 16: 3103-3111Crossref PubMed Scopus (115) Google Scholar When surgery is not possible due to significant comorbidities, surveillance colonoscopy within 6 months after polyp removal is recommended, as well as close oncological follow-up including CT scan to detect lymph node recurrences [IV, B].38Backes Y. Elias S.G. Groen J.N. et al.Histologic factors associated with need for surgery in patients with pedunculated T1 colorectal carcinomas.Gastroenterology. 2018; 154: 1647-1659Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar,39Bujanda L. Cosme A. Gil I. Arenas-Mirave J.I. Malignant colorectal polyps.World J Gastroenterol. 2010; 16: 3103-3111Crossref PubMed Scopus (115) Google Scholar Infiltrative colon cancers cannot be resected by colonoscopy and require surgery, with the goal of wide resection of the involved bowel segment and its lymphatic drainage [I, A]. The extent of the colonic resection is determined by the blood supply and distribution of regional lymph nodes. The resection should include a segment of colon of at least 5 cm on either side of the tumour, but wider margins are often included due to the mandatory ligation of the arterial blood supply [IV, B]. En bloc colonic and mesentery resection is recommended in order to clearly define stage II versus stage III and to identify and eradicate potential lymph node metastases; at least 12 lymph nodes should be resected when feasible [IV, B].40Voyer T.E.L. Sigurdson E.R. Hanlon A.L. et al.Colon cancer survival is associated with increasing number of lymph nodes analysed: a secondary survey of intergroup trial INT-0089.J Clin Oncol. 2003; 21: 2912-2919Crossref PubMed Scopus (932) Google Scholar Likewise, en bloc resection of adjacent organ-invaded portions must be carried out in case of pT4b41Xynos E. Gouvas N. Triantopoulou C. et al.Clinical practice guidelines for the surgical management of colon cancer: a consensus statement of the Hellenic and Cypriot Colorectal Cancer Study Group by the HeSMO.Ann Gastroenterol. 2016; 29: 3-17PubMed Google Scholar [I, B]. During the procedure, a complete assessment of the peritoneal cavity and ovaries should be carried out to investigate for possible metastasis41Xynos E. Gouvas N. Triantopoulou C. et al.Clinical practice guidelines for the surgical management of colon cancer: a consensus statement of the Hellenic and Cypriot Colorectal Cancer Study Group by the HeSMO.Ann Gastroenterol. 2016; 29: 3-17PubMed Google Scholar [I, C]. (See ESMO guidelines for metastatic colorectal cancer for the management of patients with removed metastases42Van Cutsem E. Cervantes A. Nordlinger B. Arnold D. Metastatic colorectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.Ann Oncol. 2014; 25: iii1-iii9Abstract Full Text Full Text PDF PubMed Scopus (820) Google Scholar). Laparoscopic colectomy can be safely carried out for colon cancer when technical expertise is available in the absence of contraindications in view of reduced morbidity, improved tolerance and similar oncological outcomes [I, C].43Nelson H. Sargent D.J. Wieand H.S. et al.A comparison of laparoscopically assisted and open colectomy for colon cancer.N Engl J Med. 2004; 350: 2050-2059Crossref PubMed Scopus (2879) Google Scholar,44Hewett P.J. Allardyce R.A. Bagshaw P.F. et al.Short-term outcomes of the Australasian randomized clinical study comparing laparoscopic and conventional open surgical treatments for colon cancer: the ALCCaS trial.Ann Surg. 2008; 248: 728-738Crossref PubMed Scopus (269) Google Scholar Obstructive CRCs can be treated in one or two stages. Two-stage procedures can include colostomy followed by colonic resection or, in the case of bowel perforation, Hartmann’s procedure followed by colostomy closure and anastomosis. One-stage procedures are preferred when carried out by experienced teams; subtotal colectomy and ileorectal anastomosis or segmental resection after intraoperative colonic lavage are alternatives in selected cases [III]. Colonic stenting45Ribeiro I.B. Bernardo W.M. Martins B.D.C. et al.Colonic stent versus emergency surgery as treatment of malignant colonic obstruction in the palliative setting: a systematic review and meta-analysis.Endosc Int Open. 2018; 6 ([published correction appears in Endosc Int Open 2018;6:C1]): E558-E567Crossref PubMed Google Scholar,46van Hooft J.E. Veld J.V. Arnold D. et al.Self-expandable metal stents for obstructing colonic and extracolonic cancer: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2020.Endoscopy. 2020; 52: 389-407Crossref PubMed Scopus (101) Google Scholar can be used in expert centres as a bridge to elective surgery, especially in patients with higher rates of postoperative complication after emergency surgery [>70 years old and/or American Society of Anesthesiologists (ASA) >II] [II]. •En bloc endoscopic resection of the polyp is sufficient for non-invasive (pTis, i.e. intraepithelial or intramucosal) adenocarcinomas [IV, B].•The presence of invasive carcinoma (pT1) in a polyp requires a thorough review with the pathologist and surgeon. High-risk features mandating surgical resection with lymphadenectomy include lymphatic or venous invasion, grade 3 differentiation, significant (grade >1) and tumour budding [IV, B].•Laparoscopic colectomy can be safely carried out for colon cancer when technical expertise is available in the absence of contraindications, in view of reduced morbidity, improved tolerance and similar oncological outcomes [I, C].•Obstructive CRCs can be treated in one- or two-stage procedures, as indicated [III, B]. Pathological reporting should be carried out at the time of surgery to precisely define nodal spread of disease and extension of the tumour through the bowel wall and on to adjacent structures, as well as to assess biopsies when a suspicion of liver or peritoneal metastases has been identified by the surgeon. The standard assessment should include47Washington M.K. Berlin J. Branton P. et al.Protocol for the examination of specimens from patients with primary carcinoma of the colon and rectum.Arch Pathol Lab Med. 2009; 133: 1539-1551Crossref PubMed Google Scholar:•morphological description of the specimen;•surgical procedure carried out;•definition of tumour site and size;•presence or absence of macroscopic tumour perforation;•histological type and grade;•extension of tumour into the bowel wall and adjacent organs (T stage);•distance of cancer from resected margins (proximal, distal and radial);•presence or absence of tumour deposits;•lymphovascular and/or perineural invasion;•presence of tumour budding37Lugli A. Kirsch R. Ajioka Y. et al.Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016.Mod Pathol. 2017; 30: 1299-1311Crossref PubMed Scopus (477) Google Scholar;•site and number of removed regional lymph nodes and their possible infiltration by cancer cells (N stage);•involvement of other organs (e.g. peritoneum) if submitted either removed or biopsied (M stage);•mismatch repair (MMR)/microsatellite instability (MSI) status of the tumour. The pathological stage must be reported according to the Union for International Cancer Control (UICC) tumour, node, metastasis (TNM) classification, 8th edition48Brierley J.D. Gospodarowicz M.K. Wittekind C. TNM Classification of Malignant Tumours. 8th edition. John Wiley & Sons, Inc., Oxford2016Google Scholar (see supplementary Table S1, available at https://doi.org/10.1016/j.annonc.2020.06.022). •A standard surgical/pathological report should include specimen description and surgical procedure, tumour site and size, macroscopic tumour perforation, histological type and grade, extension into the bowel wall and adjacent organs, distance of cancer from rese