Current treatment of pT1 rectal cancers in Denmark: A retrospective national cohort study.

AIM: Organ preservation strategies for patients with rectal cancer are increasingly common. In appropriately selected patients, local excision (LE) of pT1 cancers can reduce morbidity without compromising cancer-related outcomes. However, determining the need for completion surgery after LE can be challenging, and it is unknown if prior LE compromises subsequent total mesorectal excision (TME). The aim of this study is to describe the current management of patients with pT1 rectal cancers. METHOD: This is a retrospective national cohort study of the Danish Colorectal Cancer Group database, including patients with newly diagnosed pT1 cancers between 2016 and 2020. Patients were stratified according to treatment into LE alone, completion TME after LE or upfront TME. The treatment and outcomes of these groups were compared. RESULTS: A total of 1056 patients were included. Initial LE was performed in 715 patients (67.7%), of whom 194 underwent completion TME (27.1%). The remaining 341 patients underwent upfront TME (32.3%). Patients undergoing LE alone were more likely to be male with low rectal cancers and greater comorbidity. No differences in specimen quality or perioperative outcomes were noted between patients undergoing completion or upfront TME. Eighty-five patients (15.9%) had lymph node metastases (LNM). Pathological risk factors poorly discriminated between patients with and without LNM, with similar rates seen in patients with zero (14.1%), one (12.0%) or two (14.4%) risk factors. CONCLUSION: LE is a key component of the treatment of pT1 rectal cancer and does not appear to affect the outcomes of completion TME. Patient selection for completion TME remains a major challenge, with current stratification methods appearing to be inadequate.

Fistula development after anal abscess drainage-a multicentre retrospective cohort study.

PURPOSE: Anal abscesses are common and, despite correct treatment with surgical drainage, carry the risk of developing fistulas. Studies identifying risk factors for the development of anal fistulas are sparse. This study aimed to identify the risk factors for anal fistulas after anal abscess surgery. METHODS: This was a multicentre, retrospective cohort study of patients undergoing acute surgery for anal abscesses in the Capital Region of Denmark between 2018 and 2019. The patients were identified using ICD-10 codes for anal abscesses. Predefined clinicopathological factors and postoperative courses were extracted from patient records. RESULTS: A total of 475 patients were included. At a median follow-up time of 1108 days (IQR 946-1320 days) following surgery, 164 (33.7%) patients were diagnosed with an anal fistula. Risk factors for developing fistulas were low intersphincteric (OR 2.77, 95CI 1.50-5.06) and ischioanal (OR 2.48, 95CI 1.36-4.47) abscesses, Crohn's disease (OR 5.96, 95CI 2.33-17.2), a history of recurrent anal abscesses (OR 4.14, 95CI 2.47-7.01) or repeat surgery (OR 5.96, 95CI 2.33-17.2), E. coli-positive pus cultures (OR 4.06, 1.56-11.4) or preoperative C-reactive protein (CRP) of more than 100 mg/L (OR 3.21, 95CI 1.57-6.71). CONCLUSION: Several significant clinical risk factors were associated with fistula development following anal abscess surgery. These findings are clinically relevant and could influence the selection of patients for specialised follow-up, facilitate expedited diagnosis, and potentially prevent unnecessarily long treatment courses.

Robot-assisted TAMIS: a systematic review of feasibility and outcomes.

BACKGROUND: In the advancement of transanal local excision, robot-assisted transanal minimal invasive surgery is the newest development. In the confined area of the rectum, robot-assisted surgery should, theoretically, be superior due to articulated utensils, video enhancement, and tremor reduction, however, this has not yet been investigated. The aim of this study was to review the evidence reported to-date on experience of using robot-assisted transanal minimal invasive surgery for treatment of rectal neoplasms. METHODS: A comprehensive literature search of Embase and PubMed from May to August 2021were performed. Studies including patients diagnosed with rectal neoplasia or benign polyps who underwent robot-assisted transanal minimal invasive surgery were included. All studies were assessed for risk of bias through assessment tools. Main outcome measures were feasibility, excision quality, and complications. RESULTS: Twenty-five studies with a total of 322 local excisions were included. The studies included were all retrospective, primarily case-reports, -series, and cohort studies. The median distance from the anal verge ranged from 3.5 to 10 cm and the median size was between 2.5 and 5.3 cm. Overall, 4.6% of the resections had a positive resection margin. The overall complication rate was at 9.5% with severe complications (Clavien-Dindo score III) at 0.9%. CONCLUSION: Based on limited, retrospective data, with a high risk of bias, robot-assisted transanal minimal invasive surgery seems feasible and safe for local excisions in the rectum.

Perianal Crohn's Disease and the Development of Colorectal and Anal Cancer: A Systematic Review and Meta-analysis.

BACKGROUND AND AIMS: The aim of this systematic review was to assess the literature on the incidence and risk factors for colorectal cancer and anal cancer in patients with perianal Crohn's disease. METHOD: A systematic review of the literature was performed using PubMed, Embase and Google Scholar. A meta-analysis was then conducted using a random-effects model. RESULTS: Five studies were included in the systematic review. Of the total patients, 26.5% had perianal Crohn's disease. The median follow-up was 6 years. In total, 127 cases of colorectal cancer were found [0.43% of the included Crohn's disease patients]. Perianal involvement was present in 50% of colorectal cancer patients [0.89% of the population]. Three of the studies specified the cancer to be rectal or anal, which were present in 68 and 24 cases [0.3% and 0.1% of patients], respectively. In a subgroup analysis of rectal and anal cancer, perianal involvement was most frequent in anal cancer, accounting for 46% of the cases. In the rectal cancer group, 37% had perianal involvement. The higher incidence of colorectal cancer in patients with perianal Crohn's disease was confirmed in a meta-analysis. CONCLUSION: Half of the patients with colorectal cancer and anal cancer were found to have perianal Crohn's disease. In patients with perianal involvement, there was a higher percentage of anal cancer compared with rectal cancer. These results support the theory that patients with perianal Crohn's disease are at increased risk for developing colorectal and anal cancer. Studies collecting more detailed data regarding patients and their cancers are needed to further specify the disease course.

[Treatment of perianal fistulas with mesenchymal stem cells].

Treatment of perianal fistulas are challenged by insufficient healing and a high rate of relapse. Existing sphincter-sparing procedures have healing rates of around 50%. Treatment with mesenchymal stem cells of both autologous and allogenic origin and freshly collected autologous adipose tissue show both promising healing rates and few complications and may be offered to patients with complicated fistulas not suited for other treatment modalities.

[Endoscopic vacuum-assisted treatment of a large supralevator abscess].

Supralevatory abscesses (SA) are rare entities complicating diagnosis and treatment. We present the case report of a 64-year-old male with a large SA and a low transsphincteric fistula requiring surgery. Due to comorbidities and the size of the SA an endoscopic vacuum therapy (EVC) was placed for adequate drainage with good results at the six weeks follow-up. EVC is minimally invasive with continual drainage, it promotes granulation and reduces the cavity. EVC could be a new method of treating SA in multimorbid patients. However, these patients should be chosen by an experienced surgeon.

[Transanal endoscopic microsurgery for excision of a symptomatic tailgut cyst].

A tailgut cyst is a rare tumour originating from the embryonic remnant of the retrorectal space. The cyst is often asymptomatic, but it can cause abdominal or rectal pain and urogenital symptoms. When diagnosed, resection is the choice of treatment, and traditionally open surgery has been preferred. In this case report, we present a 30-year-old female patient with a painful tailgut cyst. She was found to be candidate for transanal endoscopic microsurgery, which was successfully performed.

Effectiveness of infliximab treatment of complex idiopathic anal fistulas.

OBJECTIVES: To investigate the effects of infliximab treatment in patients with complex idiopathic anal fistulas refractory to standard surgical treatment. MATERIALS AND METHODS: We retrospectively evaluated the effects ofinfliximab treatmentin patients with complex idiopathic anal fistulas refractory to standard surgical intervention. The primary outcome was achievement of substantial clinical improvement defined as sustained, reduced inflammatory activity at perioperativeevaluation, i.e., only minimal-to-moderate secretion and induration and a reduction of fistula size of a magnitude that would make it possible to perform a lay-open or sphincter-sparring closure procedure. Secondary outcomes weresymptom improvement, adverse treatment events and fistula healing after the surgical procedure in those achieving the primary outcome. RESULTS: Twenty-two patients were included (18 high transsphincteric, 3complex low transsphincteric, 1 suprasphincteric fistula). Fistulas had been present for a median of 24 [interquartile range, IQR: 12-33] months. In total, 16 patients (73%) achieved the primary outcome of substantial clinical improvement. Median time from infliximab initiation to patients achieved the primary outcome was 11 [IQR: 8-22] months. Sixteen of the patients responding to infliximab received subsequent lay-open or sphincter-sparring closure procedure surgery. Of these, ten (63%) achieved fistula healing. No serious infectious complications to infliximab treatment were seen. One patient developed a new abscess. One patient developed psoriasis (pustolosispalmoplantaris). CONCLUSIONS: Infliximab treatment may be considered a supplement to repeated curettage and setondrainage in the management of selected, complex idiopathic anal fistulas. Such combined treatment may make otherwise refractory fistulas amenable to definitive closure attempts.

Incidence of Incisional Hernia Repair After Laparoscopic Compared to Open Resection of Colonic Cancer: A Nationwide Analysis of 17,717 Patients.

BACKGROUND: It remains unknown whether laparoscopic compared to open surgery translates into fewer incisional hernia repairs (IHR). The objectives of the current study were to compare the long-term incidence of IHR and the size of repaired hernias between patients subjected to laparoscopic or open resection of colonic cancer. METHODS: This was a nationwide cohort study comprised of patients undergoing resection for colonic cancer between January 2007 and March 2016 according to the Danish Colorectal Cancer Group database. Patients who subsequently underwent IHR were identified in the Danish Ventral Hernia Database, from which information about the priority of the hernia repair and the size of the fascial defect was retrieved. RESULTS: The study included 17,717 patients, of whom 482 (2.7%) underwent subsequent IHR during a median follow-up of 4.7 (interquartile range 2.8-6.9) years. There was no significant difference in the 5-year cumulative incidence of hernia repair after laparoscopic compared to open colonic resection (3.9%, CI 3.3-4.4% vs 4.1%, CI 3.5-4.6%). After adjustment for confounders, laparoscopic approach was associated with an increased rate of emergency IHR (HR 2.37, 95% CI 1.03-5.46, P = 0.042) as opposed to elective IHR (HR 0.91, 95% CI 0.73-1.14, P = 0.442). Laparoscopic surgery was significantly associated with a decreased fascial defect area compared to open surgery (mean difference -16.0 cm2, 95% CI -29.4 to -2.5, P = 0.020). CONCLUSIONS: There was no difference in the incidence of IHR after open compared to laparoscopic resection. Compared to the open approach, laparoscopic resection increased the rate of subsequent emergency IHR, suggesting that a more aggressive therapeutic approach may be warranted in this patient group upon diagnosis of an incisional hernia.

Increased Leak Rates Following Stapled Versus Handsewn Ileocolic Anastomosis in Patients with Right-Sided Colon Cancer: A Nationwide Cohort Study.

BACKGROUND: Data on anastomotic leak rates after stapled versus handsewn ileocolic anastomosis are conflicting. In a Cochrane review, the combined estimate favored the stapled technique, but recent cohort studies demonstrated a 2-fold increase in anastomotic leak with the stapled approach. OBJECTIVE: The purpose of this study was to investigate anastomotic leak rates following stapled versus handsewn ileocolic anastomosis. DESIGN: This was a nationwide, retrospective cohort study. SETTING: Data were obtained from the Danish Colorectal Cancer Group and National Patient Registry databases. PATIENTS: Danish patients, ≥18 years of age, undergoing right hemicolectomy for a first-time diagnosis of adenocarcinoma in the right colon with primary anastomosis between October 2014 and December 2015 were included. MAIN OUTCOME MEASURES: The primary outcome was anastomotic leak rate. Secondary outcomes included 30-day mortality. Covariates included demographics, comorbidity, tumor stage, and surgical variables. Multivariable logistic regression and propensity score matching were used to adjust for confounding. RESULTS: The 1414 patients included 391 (28%) in the stapled group and 1023 (72%) in the handsewn group. Forty-five patients (3.2%) developed anastomotic leak: 21 of 391 (5.4%) and 24 of 1023 (2.4%) in the stapled and handsewn group (p = 0.004). This difference was confirmed in multivariable analysis (adjusted OR, 2.91; 95% CI, 1.53-5.53; p < 0.001), and after propensity score matching (OR, 2.41; 95% CI, 1.24-4.67; p = 0.009). Thirty-day mortality was 15.6% (7/45) and 2.1% (29/1369) in patients with and without anastomotic leak (p < 0.001), with no difference between the stapled and handsewn approach. LIMITATIONS: The study's design was retrospective, with no information on allocation to the stapled or handsewn approach. CONCLUSIONS: The present study demonstrated a 2-fold increase in anastomotic leak after stapled versus handsewn ileocolic anastomoses. Previous opinions on the optimal anastomosis technique for colon cancer should be scrutinized given the devastating short-term outcome of anastomotic leak. See Video Abstract at http://links.lww.com/DCR/A819.

Pancreatic function following post-endoscopic retrograde cholangiopancreatography pancreatitis: A controlled cohort study with long-term follow-up.

BACKGROUND: Acute pancreatitis is one of the most common causes of gastrointestinal-related hospitalization and the incidence is increasing. Endo- and exocrine pancreatic function can be compromised after acute pancreatitis. OBJECTIVE: The purpose of this study was to explore the long-term consequences of post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) on pancreatic function. METHODS: A follow-up study was carried out with prospective assessment of endo- and exocrine pancreatic function among cases with previous PEP and matched controls from a Danish cohort consisting of 772 patients undergoing first-time ERCP. Pancreatic function was evaluated by faecal-elastase-1 test, blood levels of haemoglobin A1c, C-peptide, vitamin B12, vitamin D and indirectly by changes in body weight. RESULTS: Twenty-nine cases and 49 controls participated in the study. Mean follow-up time (standard deviation) was 58 (21) months. Twelve (41%), eight (28%) and nine (31%) patients had mild, moderate and severe PEP, respectively. There was no difference between cases and controls with regard to pancreatic function parameters and PEP severity was not associated with pancreatic function. Factors associated with pancreatic function impairment included body mass index, alcohol consumption, age and smoking. CONCLUSION: This study suggests that long-term pancreatic function following PEP is similar to the pancreatic function of other patients with comparable gallstone-related morbidity.

Oncological outcome following laparoscopic versus open surgery for cancer in the transverse colon: a nationwide cohort study.

BACKGROUND: The literature on transverse colonic cancer resection is sparse. The optimal surgical approach for this disease is thus unknown. This study aimed to examine laparoscopic versus open surgery for transverse colonic cancer. METHODS: This study was a nationwide, retrospective cohort study of all patients registered with a transverse colonic cancer in Denmark between 2010 and 2013. Data were obtained from the Danish Colorectal Cancer Group, the Danish Pathology Registry, Danish National Patient Registry, and patients' records. Main outcome measures were surgical resection plane, lymph node yield, and long-term cancer recurrence and survival. RESULTS: In total, 357 patients were included. Non-mesocolic resection was more frequent with laparoscopic compared with open resection (adjusted odds ratio 2.44, 95% CI 1.29-4.60, P = 0.006). Median number of harvested lymph nodes was higher after open compared with laparoscopic resection (22 versus 19, P = 0.03). Non-mesocolic resection (adjusted hazard ratio 2.45, 95% CI 1.25-4.79, P = 0.01) and increasing tumor stage (P < 0.001) were factors associated with recurrence. Cancer recurrence was significantly associated with an increased risk of mortality (adjusted hazard ratio 4.32, 95% CI 2.75-6.79, P < 0.001). Overall mortality was, however, not associated with the surgical approach or surgical plane. CONCLUSIONS: Although associated with a lower rate of mesocolic resection plane and fewer lymph nodes harvested, laparoscopic surgery for transverse colonic cancers led to similar long-term results compared with open resection.

Treatment of Complex Fistula-in-Ano With a Nitinol Proctology Clip.

BACKGROUND: The treatment of complex anocutaneous fistulas remains a major therapeutic challenge balancing the risk of incontinence against the chance of permanent closure. OBJECTIVE: The purpose of this study was to investigate the efficacy of a nitinol proctology clip for closure of complex anocutaneous fistulas. DESIGN: This is a single-center cohort study with retrospective analysis of all of the treated patients. SETTINGS: Data were obtained from patient records and MRI reports, as well as follow-up telephone calls and clinical follow-up with endoanal ultrasonography. PATIENTS: All of the patients were treated for high transsphincteric and suprasphincteric anocutaneous fistulas at the Digestive Disease Center, Bispebjerg Hospital, between May 2013 and February 2015. INTERVENTIONS: All of the patients were treated with the nitinol proctology clip. MAIN OUTCOME MEASURES: Primary outcome was fistula healing after proctology clip placement, as evaluated through clinical examination, endoanal ultrasonography, and MRI. RESULTS: The fistula healing rate 1 year after the clip procedure was 54.3% (19 of 35 included patients). At the end of follow-up, 17 (49%) of 35 patients had persistent closure of the fistula tracks. No impairment of continence function was observed. Treatment outcome was not found to be statistically associated with any clinicopathological characteristics. LIMITATIONS: The study is limited by its retrospective and nonrandomized design. Selection bias may have occurred, because treatment options other than the clip were available during the study period. The small number of patients means that there is a nonnegligible risk of type II error in the conclusion, and the follow-up may be too short to have detected all of the failures. CONCLUSIONS: Healing rates were comparable with those of other noninvasive, sphincter-sparing techniques for high-complex anocutaneous fistulas, with no risk of incontinence. Predictive parameters for fistula healing using this technique remain uncertain. See Video Abstract at http://links.lww.com/DCR/A347.

Differential Impact of Anastomotic Leak in Patients With Stage IV Colonic or Rectal Cancer: A Nationwide Cohort Study.

BACKGROUND: Anastomotic leak has a negative impact on the prognosis of patients who undergo colorectal cancer resection. However, data on anastomotic leak are limited for stage IV colorectal cancers. OBJECTIVE: The purpose of this study was to investigate the impact of anastomotic leak on survival and the decision to administer chemotherapy and/or metastasectomy after elective surgery for stage IV colorectal cancer. DESIGN: This was a nationwide, retrospective cohort study. SETTINGS: Data were obtained from the Danish Colorectal Cancer Group, the Danish Pathology Registry, and the National Patient Registry. PATIENTS: Patients who were diagnosed with stage IV colorectal cancer between 2009 and 2013 and underwent elective resection of their primary tumors were included. MAIN OUTCOME MEASURES: The primary outcome was all-cause mortality depending on the occurrence of anastomotic leak. Secondary outcomes were the administration of and time to adjuvant chemotherapy, metastasectomy rate, and risk factors for leak. RESULTS: Of the 774 patients with stage IV colorectal cancer who were included, 71 (9.2%) developed anastomotic leaks. Anastomotic leak had a significant impact on the long-term survival of patients with colon cancer (p = 0.04) but not on those with rectal cancer (p = 0.91). Anastomotic leak was followed by the decreased administration of adjuvant chemotherapy in patients with colon cancer (p = 0.007) but not in patients with rectal cancer (p = 0.47). Finally, anastomotic leak had a detrimental impact on metastasectomy rates after colon cancer but not on resection rates of rectal cancer. LIMITATIONS: Retrospective data on the selection criteria for primary tumor resection and metastatic tumor load were unavailable. CONCLUSIONS: The impact of anastomotic leak on patients differed between stage IV colon and rectal cancers. Survival and eligibility to receive chemotherapy and metastasectomy differed between patients with colon and rectal cancers. When planning for primary tumor resection, these factors should be considered.

[Positron emission tomography/computed tomography in follow-up programmes for patients with colorectal cancer].

The current follow-up programmes for patients with colorectal cancer (CRC) after curative surgery do not include 18F-fluorodeoxyglucose-positron emission tomography (PET). Several small studies on selected patient populations indicate a high sensitivity of PET/computed tomography (CT) on visualizing relapse in patients with CRC after curative surgery. Therefore, PET/CT could probably be valuable in patients with unexplained increase in carcinoembryonic antigen level or a clinical suspicion of relapse, but PET/CT is not recommended as a standard in follow-up after CRC.

Pulmonary nodules and metastases in colorectal cancer.

Patients with newly diagnosed colorectal cancer (CRC) are subjected to a preoperative thoraco-abdominal CT scan to determine the cancer stage. This staging is of relevance with regard to treatment and prognosis. About 20% of the patients have distant metastatic spread at the time of diagnosis, i.e. synchronous metastases. Most common are hepatic metastases followed by pulmonary involvement. The optimal staging modality for detecting synchronous pulmonary metastases is debated. It has been argued, that synchronous pulmonary metastases (SPCM) are rare in CRC and that the consequence of detecting SPCM is minimal. Furthermore, the current staging practice is complicated by a high number of incidental findings on the thoracic CT, so-called indeterminate pulmonary nodules (IPN). IPN can potentially represent SPCM. The purpose of this thesis was to estimate the prevalence, characteristics and clinical significance of IPN and SPCM detected at the primary staging in CRC. Study I was a systematic review of published studies on IPN in CRC focusing on the prevalence and radiological characteristics of IPN proving to be malignant. This knowledge would be of value in management strategies for IPN. On average 9% of all patients staged with a thoracic CT had IPN, however, the prevalence varied significantly between patients series. This was mainly attributed to varying/lacking definitions on IPN and variable radiological expertise in the assessment of the scans. Data were too inconsistently reported in the case series for a robust statement to be made on potential radiological characteristics suggestive of malignancy in IPN. Lymph node metastasis was the most common clinicopathological finding associated with malignancy of IPN. In conclusion, one patient of every 100 scanned patients had an IPN proving to a SPCM at follow-up, but we found no evidence that IPN should result in intensified diagnostic work-up besides routine follow-up for CRC. Study II was an analysis of the prevalence of and risk factors for SPCM in a Danish nationwide cohort of patients with newly diagnosed CRC from 2001 to 2011. SPCM were detected in 7.5% of the patients and in 37% of these cases the metastatic spread was confined to the lungs. The prevalence of SPCM increased with the implementation of thoracic CT in CRC staging. SPCM impaired survival significantly and was associated with increasing age and rectal cancer. Resection of the primary tumour, resection of the SPCM and treatment with chemotherapy were associated with improved survival. Unfortunately, however, only very few patients were subjected to all three treatment measures, and the improved prognosis could simply be the result of a selection bias. The inter-observer variation in classification of findings at thoracic CT scans was investigated in study III and was based on staging CT scans from a local cohort of patients with newly diagnosed CRC. Based on an experienced thoracic radiologist's assessment of the scans, we searched for radiological characteristics of IPN that could predict malignancy of the nodule. There was a significant difference in the number of IPNs detected between the primary and the thoracic radiologist's assessment. The thoracic radiologist classified fewer nodules as IPN and even reported with higher specificity and sensitivity for SPCM. More than 20% of IPNs (as classified by the thoracic radiologist) proved to be SPCM. Unfortunately, no radiological characteristics could be associated with a malignant outcome. In continuation of these findings we suggested a secondary review of scans with IPN be a group of dedicated thoracic radiologists. This approach might reduce the need for additional work-up for IPN and calls for clarification in future prospective studies. Identification of patients in particular risk of SPCM could be of value in the assessment of pulmonary nodules. Several biomarkers have been proposed for differential metastatic patterns in CRC. In study IV we investigated the significance of mismatch repair status (MMR) for the location of metastatic spread in a nationwide Danish cohort of patients with newly diagnosed CRC between 2010 and 2012. Deficient MMR was associated with a reduced risk of synchronous metastatic disease, however, the risk reduction only applied to hepatic metastases. MMR had no impact on SPCM and is therefore currently of no use in the assessment of IPN.

[Amyloidosis presenting as melaena]. / Melæna som debutsymptom ved amyloidose.

Amyloidosis is a disease characterized by abnormal extracellular deposits of protein. The disease may affect the stomach, however, symptoms are rare in this case. Furthermore, the rare symptoms are diffuse and unspecific and the diagnosis relies on biopsy. We report the case of a 79-year-old female presenting with melaena and no history of amyloidosis. Gastroscopy raised suspicion of a malignant process in the stomach, but biopsy revealed gastric amyloidosis. The treatment of gastric involvement is primarily symptomatic, and causal treatment is reserved for the few.

Association of Comorbidity with Anastomotic Leak, 30-day Mortality, and Length of Stay in Elective Surgery for Colonic Cancer: A Nationwide Cohort Study.

BACKGROUND: Comorbidity has a negative influence on the long-term prognosis in patients with colorectal cancer, whereas its impact on the postoperative course is less clear. OBJECTIVES: The aim of this study was to investigate the influence of comorbidity on anastomotic leak and short-term outcomes after resection for colonic cancer. DESIGN: This is a retrospective nationwide cohort study SETTING: : Data were obtained from the Danish Colorectal Cancer Group and the National Patient Registry. PATIENTS: Patients with colonic cancer undergoing elective resection between 2001 and 2008 were selected. MAIN OUTCOME MEASURES: The primary outcome was the ability of comorbidity to predict anastomotic leak. Secondary outcomes were 30-day mortality and length of stay. Comorbidity was assessed by the Charlson Comorbidity Index. Multivariable logistic regression and receiver operating characteristics curves were used to adjust for confounding. RESULTS: The rate of anastomotic leak was 535/8597 (6.2%). The mean (95% CI) Charlson score was 0.83 (0.72-0.94) and 0.63 (0.61-0.66) for patients with and without anastomotic leak, p < 0.001. The Charlson score, as assessed in the multivariable analysis (adjusted OR, 1.07; 95% CI, 0.99-1.15; p = 0.077) and by receiver operating characteristics curves (area under the curve = 0.548), failed to predict anastomotic leak. Thirty-day mortality was 425/8587 (4.9%). In patients with anastomotic leakage, a Charlson score of ≥ 2 was associated with increased mortality in comparison with a Charlson score of <2 (adjusted HR, 1.58; 95% CI, 1.00-2.51; p = 0.047). Mean length of stay was 8.7 days (95% CI, 8.4-9.2 days) for patients without an anastomotic leak in comparison with 23.3 days (95% CI, 21.5-25.1 days) for patients with anastomotic leak and 25.5 days (95% CI, 21.7-29.3 days) in patients with anastomotic leak and a Charlson score of >2, p < 0.001. LIMITATIONS: This study is limited by the accuracy of the coding used to generate the Charlson Comorbidity Index and the retrospective study design. CONCLUSION: Comorbidity failed to predict anastomotic leak, but it was associated with an inferior short-term outcome in patients with this surgical complication.