Danish Colorectal Cancer Group Research Articles

Neoadjuvant chemotherapy in patients undergoing colonic resection for locally advanced nonmetastatic colon cancer: Anationwide propensity score matched cohort study.

Neoadjuvant chemotherapy (NCT) for nonmetastatic colon cancer is not routinely used, and is currently only recommended as a treatment option for a subgroup of patients with T4b colon cancers in clinical guidelines. However, NCT may cause downstaging of the tumour, increase resectability, eradicate micrometastases and thereby improve long-term outcomes for patients with nonmetastatic colon cancer. The aim of this study was to investigate the short-term postoperative outcomes in a nationwide cohort of patients with locally advanced colon cancer (LACC) receiving NCT. Using the Danish Colorectal Cancer Group Database, data were retrieved on patients diagnosed with LACC (defined as clinical T3 with extramural tumour invasion >5mm or T4) and treated with resection with a curative intent between 2015 and 2019. Propensity score matching (PSM) in a 1:1 ratio was performed to compare short-term surgical and oncological outcomes in patients receiving NCT with patients operated on without receiving NCT. A total of 179 LACC patients were treated with NCT and 1131 were not. After PSM, 145 patients remained in each group. We found no significant differences in any short-term postoperative outcomes between the two groups. We found significant differences in favour of NCT regarding radicality and pathological N category [86% vs. 81% R0 (P=0.029) and 51% vs. 46% pN0 (P=0.017), respectively]. Neoadjuvant chemotherapy for LACC does not result in worse short-term postoperative outcomes and may increase the R0 rate as well as node-negative disease. Results on long-term benefits including survival are awaited from several ongoing randomized controlled trials.

Anastomosis technique and leakage rates in minimally invasive surgery for right-sided colon cancer. A retrospective national cohort study.

The aim of this study was to describe the different techniques currently used in Denmark to construct right-sided ileocolic anastomoses in minimally invasive surgery, and investigate, compare and analyse the anastomotic configurations and their anastomotic leakage (AL) rates. This was a retrospective register-based, study design using prospectively collected data from the Danish Colorectal Cancer Group (DCCG) database. All patients aged 18years or older with a malignant colorectal tumour in Denmark in the period of 1 February 2015 until 31 December 2019, and who had an elective, curative, minimally invasive right hemicolectomy (MIRH) with ileocolic anastomosis, were included. Three thousand three hundred ninety-eight patients were included. The most commonly used anastomotic approach was the extracorporeal (EC) hand-sewn anastomosis (HA) with end-to-end configuration (59%) and the second most used was the EC stapled anastomosis (SA) side-to-side configuration (20%). The latter had a higher AL rate compared with the hand-sewn technique (3.8% vs. 1.3%), and had significantly higher odds ratio (OR) (OR: 2.85, 95% CI: 1.56-4.92, p < 0.0001) for AL in the adjusted regression model. The least used technique was the end-to-side HA which also had a significantly higher OR (OR: 3.05, 95% CI: 1.30-7.15, p = 0.010) compared with the end-to-end HA. Smoking was an independent factor associated with higher OR for AL. The ileocolic end-to-end HA was the most commonly used technique and had the lowest AL rate in MIRH for colon cancer. The EC SA technique and tobacco smoking were independent risk factors for leakage of the ileocolic anastomosis.

Epidural Analgesia and Recurrence after Colorectal Cancer Surgery: A Danish Retrospective Registry-based Cohort Study.

Surgery is the main curative treatment for colorectal cancer. Yet the immunologic and humoral response to surgery may facilitate progression of micro-metastases. It has been suggested that epidural analgesia preserves immune competency and prevents metastasis formation. Hence, the authors tested the hypothesis that epidural analgesia would result in less cancer recurrence after colorectal cancer surgery. The Danish Colorectal Cancer Group Database and the Danish Anesthesia Database were used to identify patients operated for colorectal cancer between 2004 and 2018 with no residual tumor tissue left after surgery. The exposure group was defined by preoperative insertion of an epidural catheter for analgesia. The primary outcome was colorectal cancer recurrence, and the secondary outcome was mortality. Recurrences were identified using a validated algorithm based on data from Danish health registries. Follow-up was until death or September 7, 2018. The authors used propensity score matching to adjust for potential preoperative confounders. In the study population of 11,618 individuals, 3,496 (30.1%) had an epidural catheter inserted before surgery. The epidural analgesia group had higher proportions of total IV anesthesia, laparotomies, and rectal tumors, and epidural analgesia was most frequently used between 2009 and 2012. The propensity score-matched study cohort consisted of 2,980 individuals in each group with balanced baseline covariates. Median follow-up was 58 months (interquartile range, 29 to 86). Recurrence occurred in 567 (19.0%) individuals in the epidural analgesia group and 610 (20.5%) in the group without epidural analgesia. The authors found no association between epidural analgesia and recurrence (hazard ratio, 0.91; 95% CI, 0.82 to 1.02) or mortality (hazard ratio, 1.01; 95% CI, 0.92 to 1.10). In colorectal cancer surgery, epidural analgesia was not statistically significantly associated with less cancer recurrence.

Sixty-Day Mortality of Patients With Metastatic Colorectal Cancer Randomized to Systemic Treatment vs Primary Tumor Resection Followed by Systemic Treatment

The role of primary tumor resection (PTR) in synchronous patients with metastatic colorectal cancer (mCRC) who had unresectable metastases and few or absent symptoms of their primary tumor is unclear. Studying subgroups with low postoperative mortality may identify patients who potentially benefit from PTR. To determine the difference in 60-day mortality between patients randomized to systemic treatment only vs PTR followed by systemic treatment, and to explore risk factors associated with 60-day mortality. CAIRO4 is a randomized phase 3 trial initiated in 2012 in which patients with mCRC were randomized to systemic treatment only or PTR followed by systemic treatment with palliative intent. This multicenter study was conducted by the Danish and Dutch Colorectal Cancer Group in general and academic hospitals in Denmark and the Netherlands. Patients included between August 2012 and December 2019 with histologically proven colorectal cancer, unresectable metastases, and a primary tumor with few or absent symptoms were eligible. Systemic treatment, consisting of fluoropyrimidine-based chemotherapy with bevacizumab vs PTR followed by fluoropyrimidine-based chemotherapy with bevacizumab. The aim of the current analysis was to compare 60-day mortality rates in both treatment arms. A secondary aim was the identification of risk factors for 60-day mortality in the treatment arms. These aims were not predefined in the study protocol. A total of 196 patients were included in the intention-to-treat analysis (112 [57%] men; median [IQR] age, 65 [59-70] years). Sixty-day mortality was 3% (95% CI, 1%-9%) in the systemic treatment arm and 11% (95% CI, 6%-19%) in the PTR arm (P = .03). In a per-protocol analysis, 60-day mortality was 2% (95% CI, 1%-7%) vs 10% (95% CI, 5%-18%; P = .048). Patients with elevated serum levels of lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, and/or neutrophils who were randomized to PTR had a significantly higher 60-day mortality than patients without these characteristics. Patients with mCRC who were randomized to PTR followed by systemic treatment had a higher 60-day mortality than patients randomized to systemic treatment. Especially patients randomized to the PTR arm with elevated serum levels of lactate dehydrogenase, neutrophils, aspartate aminotransferase, and/or alanine aminotransferase were at high risk of postoperative mortality. Final study results on overall survival have to be awaited. ClinicalTrials.gov Identifier: NCT01606098.

The Impact of Patient Characteristics and Tumor Biology on the Accuracy of Preoperative Staging of Colon Cancer in Denmark. A Nationwide Cohort Study.

Simple SummaryThe roles of mismatch repair and other colon tumor characteristics were investigated in a nationwide registry study with data extracted from the Danish Colorectal Cancer Group. Mismatch repair can arise during DNA replication. In this study, 6102 patients were included with a median age of 72 (range 23–97 years). The mismatch repair was deficient in 24% and proficient in 76%. Mismatch repair deficiency impacted the accuracy of the preoperative staging of colon cancer. In the future, mismatch repair status should be taken into consideration in the clinical staging of colon cancer.Background: Colon cancer is a common disease in western populations. The aim of this study was to assess the impact of mismatch repair (MMR) deficiency and other patient and tumor characteristics on the accuracy of preoperative staging by comparing histopathological T- and N-categories of the resected specimen with the preoperative clinical stage in a nationwide cohort of patients treated for colon cancer by elective bowel resection with curative intent. Methods: A register study of a cohort extracted from the Danish Colorectal Cancer Group (DCCG) database, which holds prospective data on all new cases of colon and rectum cancer in Denmark. Patients diagnosed with colon cancer and treated with an elective bowel resection with curative intent in the years 2016–2019 were analyzed. Results: A total of 6102 patients were included (n = 3161 (52%) men and n = 2941 (48%) women) with a median age of 72 years (range 23–97 years). MMR was deficient in 24% of the patients and proficient in 76%. MMR deficiency, tumor sidedness and histopathological type were significant predictors of the accuracy of preoperative staging of colon cancer in univariate and multivariate analysis. MMR status in particular showed a strong impact on the risk of overstaging. Conclusions: MMR deficiency, but also tumor sidedness and to some degree histopathological type, impacted the accuracy of preoperative staging of colon cancer. MMR status should be taken into consideration in everyday clinical staging.

A nationwide comparison of short-term outcomes after transanal, open, laparoscopic, and robot-assisted total mesorectal excision.

Laparoscopic rectal cancer surgery has several limitations. Transanal total mesorectal excision (TaTME) can potentially overcome these limitations. The aim of this study was to compare the rates of non-radical surgery and anastomotic leakage after TaTME, open TME (OpTME), laparoscopic TME (LaTME) and robotic TME (RoTME) procedures in a nationwide cohort. We extracted the demographic, perioperative and pathological data of patients who underwent a curative OpTME, LaTME, RoTME or TaTME procedure between January 2014 and December 2018 from the national database of the Danish Colorectal Cancer Group (DCCG). We conducted multiple group-comparisons, uni- and multivariate analyses to determine the factors associated with positive resection margin (+RM) and anastomotic leakage. We included 2393 patients (OpTME = 205, LaTME = 1163, RoTME = 713 and TaTME = 312). The rate of +RM was 5.7% after TaTME. The lowest rate of +RM was achieved after RoTME (8.2%, 4.7%, 2.52%, and 5.7%, after OpTME, LaTME, RoTME and TaTME respectively, p<0.001). In multivariate analysis, having a T4 tumour and intraoperative bowel perforation were associated with the risk of +RM (p<0.001, p<0.001, respectively). The factors associated with anastomotic leakage in multivariate analysis were male gender, high BMI and intraoperative bowel perforation (p<0.001, p=0.049, p=0.002, respectively). TaTME was associated with the highest rate of sphincter-saving procedures (79.8%, p<0.001), the lowest rate of bowel perforation (2.9%, p=0.028) and the lowest rate of conversion to open surgery (1.3%, p<0.001). In a nationwide audit of TME approaches, the rate of +RM was lowest after RoTME. No differences were found between the four approaches regarding the risk of anastomotic leakage. TaTME offered advantages related to sphincter-saving, perforation and conversion.

Younger age at onset of colorectal cancer is associated with increased patient’s delay

AimThis study aimed to investigate if younger age at diagnosis of colorectal cancer was associated with a diagnostic delay. The secondary objective was to evaluate if symptomatology varied with age. MethodThe study population consisted of the cohorts from two prospective multicentre studies conducted in Sweden and Denmark, the QoLiRECT and QoLiCOL studies. These studies investigated the quality of life in patients with colorectal cancer. Participants responded to the validated questionnaires used to extract information on patient’s and doctor’s delay as well as first presenting symptoms. Clinical variables were retrieved from the Swedish Colorectal Cancer Registry and the Danish Colorectal Cancer Group Database. Results2574 patients were included, 1085 from QoLiRECT and 1489 from QoLiCOL. The probability of an increased patient’s delay was higher when age decreased by 10 years (the SD in both QoLiRECT and QoLiCOL), adjusted OR 1.19 (95%CI: 1.10; 1.30), p < 0.001. A similar effect was found for doctor’s delay, but the age effect was smaller in this case, adjusted OR 1.05 (95%CI: 0.97; 1.15), p = 0.177. When the age effect was analysed non-linearly, an increased probability of a delay was seen for patients from around 60 years and below. Younger patients were equally or more likely to report the symptoms of blood in stool, diarrhoea, constipation, mucus in faeces, faecal urgency, faecal emptying difficulties and pain compared to older patients. ConclusionYounger patients were more likely to have an increased patient’s delay, probably contributing to a delayed diagnosis of colorectal cancer. Symptomatology at diagnosis was similar irrespective of age.

Robotic versus laparoscopic right colectomy for colon cancer: a nationwide cohort study.

On a national level, the minimally invasive approach is widely adopted in Denmark. The adoption of robotic colorectal surgery is increasing; however, the advantage of a robotic approach in right colectomy is still uncertain. The purpose of this study was to compare robotic right colectomy with laparoscopic right colectomy on a national level. This was a nationwide database study based on data from the Danish Colorectal Cancer Group database. Patients from all colorectal centers in Denmark in the period 2014-2018 treated with curative intend in an elective setting with either robotic or laparoscopic right colectomy were identified. Propensity score matching was performed to adjust for confounding, and the groups were compared on demographics, disease characteristics, operative data, and postoperative and pathology outcomes. Reporting was done in accordance with the STROBE statement. In total, 4002 patients were available for analysis. Propensity score matching in ratio 2:1 identified 718 laparoscopic and 359 robotic cases. After matching, we found a higher lymph node yield in the robotic group compared to the laparoscopic group, (32.5 vs. 28.4, P < 0.001), while radicality, plane of dissection, and pathological disease stages showed no differences. There were no statistical differences in morbidity and mortality. Intracorporeal anastomosis (23.7% vs. 4.5%, P < 0.001) was more commonly performed with a robotic approach. Robotic approach was associated with a significant higher lymph node yield and with similar postoperative morbidity compared to a laparoscopic approach for right colectomy.

Prediction of 90-day mortality after surgery for colorectal cancer using standardized nationwide quality-assurance data.

BackgroundPersonalized risk assessment provides opportunities for tailoring treatment, optimizing healthcare resources and improving outcome. The aim of this study was to develop a 90-day mortality-risk prediction model for identification of high- and low-risk patients undergoing surgery for colorectal cancer.MethodsThis was a nationwide cohort study using records from the Danish Colorectal Cancer Group database that included all patients undergoing surgery for colorectal cancer between 1 January 2004 and 31 December 2015. A least absolute shrinkage and selection operator logistic regression prediction model was developed using 121 pre- and intraoperative variables and internally validated in a hold-out test data set. The accuracy of the model was assessed in terms of discrimination and calibration.ResultsIn total, 49 607 patients were registered in the database. After exclusion of 16 680 individuals, 32 927 patients were included in the analysis. Overall, 1754 (5.3 per cent) deaths were recorded. Targeting high-risk individuals, the model identified 5.5 per cent of all patients facing a risk of 90-day mortality exceeding 35 per cent, corresponding to a 6.7 times greater risk than the average population. Targeting low-risk individuals, the model identified 20.9 per cent of patients facing a risk less than 0.3 per cent, corresponding to a 17.7 times lower risk compared with the average population. The model exhibited discriminatory power with an area under the receiver operating characteristics curve of 85.3 per cent (95 per cent c.i. 83.6 to 87.0) and excellent calibration with a Brier score of 0.04 and 32 per cent average precision.ConclusionPre- and intraoperative data, as captured in national health registries, can be used to predict 90-day mortality accurately after colorectal cancer surgery.

Risk of Pharmacological or Hospital Treatment for Depression in Patients with Colorectal Cancer-Associations with Pre-Cancer Lifestyle, Comorbidity and Clinical Factors.

Simple SummaryDepression is a common disorder in cancer patients. In this population-based prospective cohort study, we investigated if patients with colorectal cancer experience a higher risk of pharmacological or hospital treatment for depression than age- and gender-matched cancer-free comparison persons when differences in lifestyle, anthropometry, socioeconomic position or comorbidity where taken into account. To identify potential risk factors, we further investigated the associations between depression and antidepressant use and pre-cancer lifestyle factors, clinical factors and treatment factors. The study results may help point toward vulnerable groups of patients at risk of depression.We investigated the risk of depression in colorectal cancer (CRC) patients and associated risk factors. The 1324 patients with CRC and 6620 matched cancer-free participants from the Diet, Cancer and Health study were followed for up to 16 years for either a first hospitalization for depression or antidepressant prescription after diagnosis of CRC cancer or study entry date. Information on the outcome and covariates was retrieved from the Danish Colorectal Cancer Group database, the national health registries and questionnaires. Cumulative incidence of depression was estimated, and Cox regression models were used to evaluate the association between risk factors and depression incidence. During follow-up, 191 (14.4%) patients with CRC and 175 (2.6%) cancer-free comparison persons experienced depression. After adjustments, in the first year after cancer diagnosis, patients with CRC had a 12-fold higher hazard compared with the cancer-free population (HR, 12.01; 95% CI, 7.89–18.28). The risk decreased during follow-up but remained significantly elevated with an HR of 2.65 (95% CI, 1.61–4.36) after five years. Identified risk factors were presence of comorbidities, advanced disease stage and use of radiotherapy, while life style factors (pre-cancer or at diagnosis) and chemotherapy did not seem to contribute to the increased risk.

Completion total mesorectal excision following transanal endoscopic microsurgery does not compromise outcomes in patients with rectal cancer.

Transanal endoscopic microsurgery (TEM) represents a choice of treatment in patients with neoplastic lesions in the rectum. When TEM fails, completion total mesorectal excision (cTME) is often required. However, a concern is whether cTME increases the rate of abdominoperineal resections (APR) and is associated with higher riskof incomplete mesorectal fascia (MRF) resection. The aim of this study was to compare outcomes of cTME with primary TME (pTME) in patients with rectal cancer. This was a nationwide study on all patients with cTME from the Danish Colorectal Cancer Group database between 2005 and 2015. Patients with cTME were compared to patients with pTME after propensity score matching (matching ratio 1:2). Matching variables were age, gender, tumor distance from anal verge, American Society of Anesthesiologists (ASA) score and American Joint Committee on Cancer (AJCC) stage. A total of 60 patients with cTME were compared with 120 patients with pTME. Patients with cTME experienced more intraoperative complications as compared to pTME patients (18.3% vs. 6.7%, p = 0.021). However, there was no difference in the rate of perforations at or near the tumor/previous TEM site (6.7% vs. 2.5%, p = 0.224), conversion to open surgery (p = 0.733) or 30-day morbidity (p = 0.86). On multivariate analysis, cTME was not a risk factor for APR (OR 2.49; 95% CI 0.95-6.56; p = 0.064) or incomplete MRF (OR 1.32; 95% CI 0.48-3.63; p = 0.596). There was no difference in the rate of local recurrence between cTME and pTME (5.2% vs. 4.3%, p = 0.1), distant metastases (6.8% vs. 6.8%, p = 1), or survival (p = 0.081). The mean follow-up time was 6years. In our study, the largest so far on the subject, we find no difference in postoperative short- or long-term outcomes between cTME and pTME.

The impact of postoperative complications and delay of adjuvant chemotherapy on oncological outcomes in patients with colorectal cancer.

Postoperative complications are believed to result in poorer long-term oncological outcomes. The contribution of time to chemotherapy has not been analysed in detail. Our aim was to examine the association between postoperative complications and long-term oncological outcomes and overall survival, and the influence of delay in chemotherapy on these outcomes. The study was a nationwide register-based observational study that included patients undergoing surgery for colorectal cancer and receiving adjuvant chemotherapy in Denmark between 2010 and 2015. Information regarding postoperative complications was obtained from the Danish Colorectal Cancer Group national clinical registry. A Cox regression model was used to estimate disease-free survival, recurrence-free survival and all-cause mortality in patients surviving for 180days or more after surgery. A total of 4083 patients were included, of whom 690 had postoperative complications. Postoperative complications were associated with increased odds of delay to adjuvant chemotherapy (odds ratio 4.56, 95% CI 3.67-5.66, p<0.0001). An unadjusted analysis revealed that patients with complications had poorer disease-free survival and recurrence-free survival and had increased all-cause mortality. In multivariate analysis, postoperative complications were not associated with poorer disease-free survival [hazard ratio (HR) 1.02, 95% CI 0.88-1.18, p=0.80] recurrence-free survival (HR 1.05, 95% CI 0.89-1.25, p=0.56) or all-cause mortality (HR 1.04, 95% CI 0.86-1.26, p=0.67). This study showed no association between the occurrence of postoperative complications and long-term prognosis when adjusting for time to adjuvant chemotherapy.

Urinary dysfunction after colorectal cancer treatment and impact on quality of life-a national cross-sectional study in males.

Despite advances in the treatment of colorectal cancer, postoperative urogenital dysfunction is still a problem although its exact extent remains unclear. The aim of this study was to identify the prevalence and patterns of urinary dysfunction in men following treatment for colorectal cancer and the impact of urinary dysfunction on quality of life. A retrospective national Danish cross-sectional study was performed in patients treated for colorectal cancer between 2001 and 2014. Patients answered questionnaires on urinary function and quality of life including the International Consultation on Incontinence Modular Questionnaire-Male Lower Urinary Tract Symptoms measuring voiding and incontinence. Results were analysed based on data on demographics and treatment-related factors obtained from the Danish Colorectal Cancer Group database. A total of 5710 patients responded to the questionnaire (response rate 52.8%). In both crude analysis and after adjusting for patient-related factors (age, time since surgery and American Society of Anesthesiologists score), both voiding (P<0.0001) and incontinence scores (P<0.0001) were significantly higher after rectal cancer than after colon cancer. In the rectal cancer group, abdominoperineal excision was found to be a significant risk factor for both voiding (P<0.0001) and incontinence (P=0.011), while radiotherapy only impaired continence (P=0.014). Significant correlations between high voiding and incontinence scores and impaired quality of life were found in both groups. We found a high prevalence of urinary dysfunction following treatment for colorectal cancer, especially in the rectal cancer group. Abdominoperineal excision was the most significant risk factor for both voiding and incontinence. Urinary dysfunction significantly impairs patients' quality of life.

Urinary dysfunction after colorectal cancer treatment and its impact on quality of life - a national cross-sectional study in women.

The aim of this study was to investigate urinary dysfunction and its impact on the quality of life of colorectal cancer survivors. We also wanted to identify the risk factors for impaired urinary function. A national cross-sectional study was performed including patients treated for colorectal cancer between 2001 and 2014. Patients answered questionnaires regarding urinary function and quality of life, including the International Consultation on Incontinence Questionnaire - Female Lower Urinary Tract Symptoms (ICIQ-FLUTS), measuring filling, voiding and incontinence. Data were compared with data on demographics and treatment-related factors from the Danish Colorectal Cancer Group (DCCG) database. We found that rectal cancer treatment significantly impaired urinary function compared with colon cancer treatment (filling score p=0.003, voiding p<0.0001, incontinence p=0.0001). Radiotherapy was the single most influential risk factor for high filling (p=0.0043), voiding (p<0.0001) and incontinence (p<0.0001) scores, whereas type of rectal resection was only significant in crude analysis. Urinary dysfunction was strongly associated with an impaired quality of life. Urinary dysfunction is common after treatment for colorectal cancer, particularly if the treatment includes radiotherapy. All patients must be informed of the risk before cancer treatment, and functional outcome should be routinely assessed at follow-up.

Inhalation or total intravenous anaesthesia and recurrence after colorectal cancer surgery: a propensity score matched Danish registry-based study

BackgroundDuring colorectal cancer surgery, the immune-modulating effects of inhalation anaesthesia may create a favourable environment for metastasis formation, leading to increased risk of recurrence. Our aim was to assess the association between inhalation vs intravenous anaesthesia and cancer recurrence in patients undergoing colorectal cancer surgery. MethodsPatients undergoing colorectal cancer surgery in 2004–18 were identified in the Danish Colorectal Cancer Group Database and Danish Anaesthesia Database. After exclusion of patients with residual tumour registered in postoperative pathology reports, local endoscopic resections, and stent insertions, we classified patients according to exposure to inhalation anaesthesia. The primary outcome was recurrence (time to recurrence), whereas secondary outcomes were all-cause mortality (time to death) and disease-free survival (time to either recurrence or death). Events of recurrence and death were identified using The Danish Civil Registration System, Danish National Pathology Registry, and Danish National Patient Registry. The sub-distribution hazards approach was used to estimate hazard ratios (HRs) for recurrence, and Cox regression was used for all-cause mortality and disease-free survival. ResultsWe identified 5238 patients exposed to inhalation anaesthesia and 6322 to intravenous anaesthesia. Propensity score matching yielded 4347 individuals in each group with balanced baseline covariates. We found a weak association between recurrence and exposure to inhalation anaesthesia (HR=1.12; 95% confidence interval [CI], 1.02–1.23). The HR estimates for all-cause mortality and disease-free survival were 1.00 (95% CI, 0.93–1.07) and 1.04 (95% CI, 0.98–1.11) respectively. ConclusionExposure to inhalation anaesthesia was associated with increased risk of recurrence after colorectal cancer surgery.

Accuracy of preoperative staging with multidetector computed tomography in colon cancer.

Multidetector computed tomography (MDCT) is the main preoperative decision-making tool in colon cancer treatment, thus the validation of daily clinical practice is warranted. The only published study validating the accuracy of MDCT in a national cohort was performed more than a decade ago. With neoadjuvant chemotherapy for patients with preoperatively assessed locally advanced cancer and the emergence of other personalized treatments we aimed to validate the accuracy of MDCT in a national cohort. The study is based on the Danish Colorectal Cancer Group (DCCG) database and included all Danish patients diagnosed with primary colon adenocarcinoma between January 2015 and December 2018. The primary study outcome was the accuracy of MDCT in identifying patients with locally advanced disease. The secondary outcomes were the accuracy of predicting UICC Stage I based on predicting the tumour category (pT3-T4 versus pT1-T2) and lymph node metastasis. A total 3465 patients were included in the analyses regarding locally advanced colon cancer. The sensitivity and specificity were 0.61 (0.58-0.64) and 0.85 (0.83-0.86), respectively, for CT to predict locally advanced disease. The sensitivity and specificity were 0.63 (0.59-0.66) and 0.80 (0.78-0.81), respectively, for predicting UICC Stage I in 4496 patients. Thirty six per cent of the patients assessed as having locally advanced disease and 58% assessed as Stage I were misclassified by MDCT. The present standard in Denmark questions whether the implementation of personalized medicine such as neoadjuvant adjuvant chemotherapy and tailor-made resections based on MDCT is justified.

Extended Right Sided Colon Resection Increases the Risk of Post-Operative Complications and Does Not Reduce the Risk of Colon Cancer Local-Regional Recurrence: Nation-Wide Population-Based Study from Danish Colorectal Cancer Group Database

Background: It is controversial whether extensive resection of right-sided colon cancer (RSCC) confer oncological benefits. The aim of this study was to examine short-and long terms outcomes of extended (ERHC) surgical removal of mesocolon compared to conventional approach (CRHC). Method: This was a retrospective population-based study based on a prospectively maintained Danish Colorectal Cancer Group database. Primary outcome measure was local-regional recurrence in patients who underwent curative resection for RSCC and secondary outcome measures was 30-day post-operative complications. Distant metastasis, unplanned intraoperative adverse events (UIAEs), 30-and 90-day post-operative mortality were also investigated. Patients who had palliative or compromised resection, emergency surgery and neo-adjuvant chemo-therapy were excluded. Results: Of the 12,855 patients with RSCC retrieved, 1,151 underwent ERHC. Patients who had ERHC were younger males with a lower ASA scores, operated by colorectal surgeons, using laparoscopic approach and had a significant higher number of harvested lymph nodes.The rate of local-regional recurrence was 1.1% (136/12,855). 1.5% (249/17.174) with no difference between CRHC and ERHC (OR 1.7 CI 95% 0.63-2.18). Post-operative complications were significantly higher in ERHC even after adjusting for age, comorbidity, access to abdomen and other covariates (OR 1.26 CI 95% 1.01-1.58). No significant difference was noticed between CRHC and ERHC in the rates of distant metastasis, UIAEs and mortality. Conclusion: This large population-based registry study showed no difference in local-regional recurrence of RSCC between conventional and extended right hemicolectomy with mesenteric resection and ligation of the middle colic vessels. Extended resection was associated with higher rates of postoperative complications. Funding Statement: None. Declaration of Interests: None Ethics Approval Statement: The data retrieved from DCCG database were fully anonymized so that none of the patient in the dataset could be traced. Data management was conducted according to the national ethical guidelines. Danish Data Protection Agency (Datatilsynet) approval was obtained (RN-2018-94).

Short-term outcomes after transanal total mesorectal excision for rectal cancer in Denmark - a prospective multicentre study.

The aim of this study was to evaluate the short-term surgical and oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer during the implementation phase of this procedure in Denmark. This is a retrospective review of prospectively recorded data. Registration was initiated by the Scientific Council of the Danish Colorectal Cancer Group (DCCG.dk) in order to assess the quality of care during the implementation of TaTME. Pre-, intra- and postoperative data including early recurrences were recorded at the operating centres. From August 2016 to April 2019, 115 TaTME procedures were registered. Patients were predominantly male (74%) with mid-rectal (88%) tumours. The level of surgical complications was comparable to previous nationwide results. Anastomotic leakage occurred in 6/109 (5.5%). One urethral injury occurred. The plane of dissection was mesorectal in 60% of cases, intramesorectal in 28% and muscularis in 12%. Nonmicroradicality was seen in 8% (R1, 6%; R2, 2%). Four local recurrences occurred after a median of 23months of follow-up. One of these was multifocal. In an implementation phase where patient selection is expected, surgical and oncological results after TaTME were comparable to those of other approaches reported in the literature.

Validation of the Danish Colorectal Cancer Group (DCCG.dk) database – on behalf of the Danish Colorectal Cancer Group

The aim of this study was to validate the clinical quality database of the Danish Colorectal Cancer Group. The validation is meant to focus on core data regarding staging of the disease, treatment provided, patient-related factors and key complications. This was a database validation study assessing the completeness of the database and the accuracy of the data by re-entering core variables into an online module in a blinded fashion and comparing re-entered data with the original database data. A sample of 5% of patients from the years 2014-2017 was randomly selected. The sample of 936 patients was identified and data were re-entered. The completeness of the data retrieved was a median of 96%, 100% and 99% for preoperative, intra-operative and postoperative variables, respectively. The overall accuracy was a median of 95%. The least accurate variable was date of diagnosis (50% perfect agreement), with agreement rising to 96% when near matches defined as correct date ±30 days were included. Intra-operative variables were of high quality, as were data on surgical complications including anastomotic leakage, where agreement was 97%. This was the first major validation of the Danish Colorectal Cancer Group's database. Overall, the completeness and quality of data were high, but the validation process also identified weaknesses, which can be crucial for future users to acknowledge and consider.

The impact of mismatch repair status to the preoperative staging of colon cancer: implications for clinical management

Aims: We sought to investigate if mismatch repair (MMR) status influences the preoperative staging of local colon cancer. Methods: Data from 590 patients in the Danish Colorectal Cancer Group national clinical database who were operated on for stage I-III colon cancer in 2010-15 were included. MMR status was determined by immunohistochemistry. Results: 22.9% had deficient(d) MMR tumors. Correlation of the clinical and pathological T-category was significant for both groups. The correlation of pre- and postoperative N-category was inferior (p &gt;0.05) in dMMR cancers compared to a significant (p &lt;0.01) correlation in proficient MMR cancers. 64.8% of dMMR tumors assessed node-positive demonstrated no sign of metastatic involvement at the postoperative assessment. Conclusion: MMR status seems to impact the accuracy of preoperative lymph node staging.