Swedish Colorectal Cancer Registry Research Articles

Postoperative morbidity following Hartmann's procedure in comparison to anterior resection and abdominoperineal resection for rectal cancer-a population-based study.

There is ongoing controversy regarding the extent to which Hartmann's procedure (HP) should be used in rectal cancer treatment. This study was designed to investigate 30-day postoperative morbidity and mortality following HP, anterior resection (AR) and abdominoperineal resection (APR) for rectal cancer using a national registry. All patients operated for rectal cancer, tumour height 5-15 cm, between the years 2010 and 2017, were identified through the Swedish colorectal cancer registry. A total of 8476 patients were included: 1210 (14%) undergoing HP, 5406 (64%) AR and 1860 (22%) APR. HP was associated with an increased risk of intra-abdominal infection (OR 1.7, CI 1.26-2.28, P = 0.0004) compared to AR and APR, while APR was related to an increased risk of overall complications (OR 1.18, CI 1.01-1.40, P = 0.040). No significant difference was observed in the rate of reoperations and readmissions between HP, AR and APR, and type of surgical procedure was not a risk factor for 30-day mortality. Findings from a subgroup analysis of patients with a tumour 5-7 cm from the anal verge revealed that HP was not associated with increased risk for complications or 30-day mortality. For patients where AR is not appropriate HP is a valid alternative with a favourable outcome. APR was associated with the highest overall 30-day complication rate.

Hartmann's Procedure Versus Intersphincteric Abdominoperineal Excision in Patients with Rectal Cancer: Report from the Swedish Colorectal Cancer Registry (SCRCR).

The primary outcome was to compare overall postoperative surgical complications within 30 days after Hartmann's procedure (HP) compared with intersphincteric abdominoperineal excision (iAPE). The secondary outcome was major surgical complications (Clavien-Dindo ≥ III). There is uncertainty regarding the optimal surgical method in patients with rectal cancer when an anastomosis is unsuitable. Rectal cancer patients with a tumor height >5 cm, registered in the Swedish Colorectal Cancer Registry who received HP or iAPE electively in 2017-2020 were included, (HP, n = 696; iAPE, n = 314). Logistic regression analysis adjusting for body mass index, American Society of Anesthesiologists classification, sex, age, preoperative radiotherapy, tumor height, cancer stage, operating hospital, and type of operation was performed. Patients in the HP group were older and had higher American Society of Anesthesiologists scores. The mean operating time was less for HP (290 vs 377 min). Intraoperative bowel perforations were less frequent in the HP group, 3.6% versus 10.2%. Overall surgical complication rates were 20.3% after HP and 15.9% after iAPE (P = 0.118). Major surgical complications were 7.5% after HP and 5.7% and after iAPE (P = 0.351). Multiple regression analysis indicated a higher risk of overall surgical complications after HP (odds ratio: 1.63; 95% confidence interval = 1.09-2.45). HP was associated with a higher risk of surgical complications compared with iAPE. In patients unfit for anastomosis, iAPE may be preferable. However, the lack of statistical power regarding major surgical complications, prolonged operating time, increased risk of bowel perforation, and lack of long-term outcomes, raises uncertainty regarding recommending intersphincteric abdominoperineal excision as the preferred surgical approach.

Diverting ostomy prior to neoadjuvant treatment in rectal cancer should be used selectively: A retrospective single-center cohort study.

Rectal cancer patients commonly benefit from neoadjuvant therapy before resection surgery. For these patients, an elective ostomy diversion is frequently considered, despite the absence of conclusive evidence when a diversion is advantageous. This is a retrospective observational single-center study on a 4-year consecutive rectal cancer cohort undergoing neoadjuvant therapy, aiming at improving the understanding of risks and benefits associated with ostomy diversion. Baseline characteristics, tumor-specific data, clinical events, and outcomes were collected using the Swedish Colorectal Cancer Registry and medical records. Thirty-two (30.2%) of the 106 included patients presented with endoscopic impassable tumors at diagnosis, of which 18 (56.2%) had diverting ostomy. Three out of 14 with impassable tumor and no diversion developed a bowel obstruction. None of the patients with an endoscopically passable tumor at diagnosis (n = 74) experienced a bowel obstruction. The elective diversions (n = 40) were not associated with serious complications (Clavien-Dindo grade ⩾ 3b). Patients with a diverting ostomy (n = 30) had similar time intervals from diagnosis to neoadjuvant treatment and to definite tumor resection as those without diversion but experienced more complex primary tumor resections in terms of blood loss and operation time. An elective diverting ostomy is a relatively safe procedure in rectal cancer patients requiring neoadjuvant therapy. More than one out of five non-diverted patients with endoscopically impassable rectal tumors developed bowel obstruction and would potentially have benefited from an elective diversion.

Importance of resection margin after resection of colorectal liver metastases in the era of modern chemotherapy: population-based cohort study.

Resection margin has been associated with overall survival following liver resection for colorectal liver metastasis. The aim of this study was to examine how resection margins of 0.0 mm, 0.1-0.9 mm and ≥1 mm influence overall survival in patients resected for colorectal liver metastasis in a time of modern perioperative chemotherapy and surgery. Using data from the national registries Swedish Colorectal Cancer Registry and Swedish National Quality Registry for Liver, Bile Duct and Gallbladder Cancer, patients that had liver resections for colorectal liver metastasis between 2009 and 2013 were included. In patients with a narrow or unknown surgical margin the original pathological reports were re-reviewed. Factors influencing overall survival were analysed using a Cox proportional hazard model. A total of 754 patients had a known margin status, of which 133 (17.6%) patients had a resection margin <1 mm. The overall survival in patients with a margin of 0 mm or 0.1-0.9 mm was 42 (95% c.i. 31 to 53) and 48 (95% c.i. 35 to 62) months respectively, compared with 75 (95% c.i. 65 to 85) for patients with ≥1 mm margin, P < 0.001. Margins of 0 mm or 0.1-0.9 mm were associated with poor overall survival in the multivariable analysis, HR 1.413 (95% c.i. 1.030 to 1.939), P = 0.032, and 1.399 (95% c.i. 1.025 to 1.910), P = 0.034, respectively. Despite modern chemotherapy the resection margin is still an important factor for the survival of patients resected for colorectal liver metastasis, and a margin of ≥1 mm is needed to achieve the best possible outcome.

Assessment by a multidisciplinary team conference affects treatment strategy and overall survival in patients with synchronous colorectal liver metastases

BackgroundThe aim of this retrospective observational study was to investigate the geographical or sex differences in patients with synchronous colorectal liver metastases (sCRLM) in terms of assessment by a multidisciplinary team conference (MDT), curative treatment, and overall survival. MethodAll sCRLM patients in the South-East Health Care Region of Sweden from 2009 to 2015 were included (n = 615). Data were derived from the Swedish Colorectal Cancer Registry, Swedish Registry of Liver and Bile Surgery and medical records. ResultsPatients who had a hepatobiliary unit (HBU) at the nearest hospital were more likely to undergo liver surgery (HBU+, 37% (n = 106), compared to HBU−, 22% (n = 60); p = 0.001) and had a better median survival (p < 0.001). No sex differences were observed. In multivariate Cox regression analyses of overall survival, assessment by an MDT that included a liver surgeon was independently linked to better survival (HR 0.574, 0.433–0.760). ConclusionThere were no sex differences in access to liver surgery or overall survival, however, there were geographical inequalities, where residency near a hospital with HBU was associated with increased overall survival and the possibility to receive liver surgery. Assessment at MDT with liver surgeon present was associated with greater survival, indicating its important role for treatment.

Minor impact of anastomotic leakage in anterior resection for rectal cancer on long-term male urinary and sexual function

PurposeAnastomotic leakage after anterior resection for rectal cancer induces bowel dysfunction, but the influence on urinary and sexual function is largely unknown. This cross-sectional cohort study evaluated long-term effect of anastomotic leakage on urinary and sexual function in male patients.MethodsPatients operated with anterior resection for rectal cancer in 15 Swedish hospitals 2007–2013 were identified. Anastomotic leakage and other clinical variables were retrieved from the Swedish Colorectal Cancer Registry and medical records. Urinary and sexual dysfunction were evaluated at 4 to 11 years after surgery using the International Prostate Symptom Score, International Index of Erectile Function, and European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire CR29. The effect of anastomotic leakage on average scores of urinary and sexual dysfunction was evaluated as a primary outcome, and the single items permanent urinary catheter and sexual inactivity as secondary outcomes. The association of anastomotic leakage and functional outcomes was analyzed using regression models with adjustment for confounders.ResultsAfter a median follow-up of 84 months (interquartile range: 67–110), 379 out of 864 eligible men were included. Fifty-nine (16%) patients had anastomotic leakage. Urinary incontinence was more common in the leakage group, with an adjusted mean score difference measured by EORTC QLQ ColoRectal–29 of 8.69 (95% confidence interval: 0.72–16.67). The higher risks of urinary frequency, permanent urinary catheter, and sexual inactivity did not reach significance.ConclusionAnastomotic leakage after anterior resection had a minor negative impact on urinary and sexual function in men.

Short-term results in a population based study indicate advantage for minimally invasive rectal cancer surgery versus open

BackgroundThe aim of this study was to determine if minimally invasive surgery (MIS) for rectal cancer is non-inferior to open surgery (OPEN) regarding adequacy of cancer resection in a population based setting.MethodsAll 9,464 patients diagnosed with rectal cancer 2012–2018 who underwent curative surgery were included from the Swedish Colorectal Cancer Registry. Primary outcomes: Positive circumferential resection margin (CRM < 1 mm) and positive resection margin (R1). Non-inferiority margins used were 2.4% and 4%. Secondary outcomes: 30- and 90-day mortality, clinical anastomotic leak, re-operation < 30 days, 30- and 90-day re-admission, length of stay (LOS), distal resection margin < 1 mm and < 12 resected lymph nodes. Analyses were performed by intention-to-treat using unweighted and weighted multiple regression analyses.ResultsThe CRM was positive in 3.8% of the MIS group and 5.4% of the OPEN group, risk difference -1.6% (95% CI -1.623, -1.622). R1 was recorded in 2.8% of patients in the MIS group and in 4.4% of patients in the OPEN group, risk difference -1.6% (95% CI -1.649, -1.633). There were no differences between the groups in adjusted unweighted and weighted analyses. All analyses demonstrated decreased mortality and re-admissions at 30 and 90 days as well as shorter LOS following MIS.ConclusionsIn this population based setting MIS for rectal cancer was non-inferior to OPEN regarding adequacy of cancer resection with favorable short-term outcomes.

Hartmann’s procedure in rectal cancer surgery is often an intraoperative decision: a retrospective multicenter study

PurposeThis study aimed to investigate patient-related factors predicting the selection of rectal cancer patients to Hartmann’s procedure as well as to investigate how often, and on what grounds, anterior resection is intraoperatively changed to Hartmann’s procedure.MethodsProspectively collected data from the Swedish Colorectal Cancer Registry regarding patients with rectal cancer operated upon from January 1 2007 to June 30 2017 in the county of Skåne were retrospectively reviewed. Data were expanded with further details from medical charts. A univariable analysis was performed to investigate variables associated with unplanned HP and significant variables included in a multivariable logistic regression analysis.ResultsAltogether, 1141 patients who underwent Hartmann’s procedure (275 patients, 24%), anterior resection (491 patients, 43%), or abdominoperineal resection (375 patients, 33%) were included. Patients undergoing Hartmann’s procedure were significantly older and had more frequently comorbidity. The decision to perform Hartmann’s procedure was made preoperatively in 209 (76%) patients, most commonly because of a comorbidity (27%) or oncological reasons (25%). Patient preference was noted in 8% of cases. In 64 cases (23%), the decision was made intraoperatively, most often due to anastomotic difficulties (60%) and oncological reasons (22%). Anastomotic difficulties were most often reported due to technical difficulties, a low tumor or neoadjuvant radiotherapy. Male gender was a significant risk factor for undergoing unplanned Hartmann’s procedure.ConclusionsThe decision to perform Hartmann’s procedure was frequently made intraoperatively. Hartmann’s procedure should be considered and discussed preoperatively in old and frail patients, especially in the presence of mid-rectal cancer and/or male gender, since these factors increase the risk of intraoperative anastomotic difficulties.

Despite multi-disciplinary team discussions the socioeconomic disparities persist in the oncological treatment of non-metastasized colorectal cancer

BackgroundThe introduction of national guidelines should eliminate previously observed associations between socioeconomic status (SES) and colorectal cancer treatment. The aim of the study was to investigate whether inequalities remain. MethodsCRCBaSe, a register-linkage originating from the Swedish Colorectal Cancer Registry, was used to identify information on patient and tumour characteristics, for 83,460 patients with stage I-III disease diagnosed 2008–2021. SES was measured as disposable income (quartiles) and the highest level of education. Outcomes of interest were emergency surgery, multidisciplinary team (MDT) conference discussion, and oncological treatment. Differences in treatment between SES groups were explored using multivariable logistic regression adjusted for year of diagnosis, age at diagnosis, sex, civil status, comorbidities, tumour location and stage. ResultsPatients in the highest income quartile had a lower risk of emergency surgery (OR 0.73 95%CI 0.68–0.80), a higher chance of being discussed at the preoperative (OR 1.39 95%CI 1.28–1.51) and postoperative MDT (OR 1.41 95%CI 1.30–1.53), receiving neoadjuvant (OR 1.15 95%CI 1.06–1.25) and adjuvant treatment (OR 2.04 95%CI 1.88–2.20). Higher education level increased the odds of MDT discussion but was not associated with oncological treatment. The proportion of patients discussed at the MDT increased, with almost all patients discussed since 2016. Despite this, treatment differences remained when patients diagnosed since 2016 were analysed separately. ConclusionThere were significant differences in how patients with different SES were treated for colorectal cancer. Further action is required to investigate the drivers of these differences as well as their impact on mortality and, ultimately, eliminate the inequalities.

Mortality and morbidity after colorectal cancer resection surgery in elderly patients: a retrospective population-based study in Sweden.

Colorectal cancer is primarily a condition of older adults, and surgery is the cornerstone of treatment. As life expectancy is increasing and surgical techniques and perioperative care are developing, curative surgery is often conducted even in ageing populations. However, the risk of morbidity, functional decline, and mortality following colorectal cancer resection surgery are known to increase with increasing age. This study aims to describe real-world data about postoperative mortality and morbidity after resection surgery for colorectal cancer in the elderly (≥ 70years) compared to younger patients (< 70years), in a Swedish setting. A cohort study including all patients diagnosed with colorectal cancer in a Swedish region of 1.7 million inhabitants between January 2016 and May 2020. Patients were identified through the Swedish Colorectal Cancer Registry, and all baseline and outcome variables were extracted from the registry. The following outcome measures were compared between the two age groups: 90-day mortality rates, postoperative complications, postoperative intensive care, reoperations, readmissions, and 1-year mortality. To adjust the analyses for baseline confounders in the comparison of the outcome variables, the following methods were used: marginal matching, calliper (ID matching), and logistic regression adjusted for baseline confounders. The cohort consisted of 5246 patients, of which 3849 (73%) underwent resection surgery. Patients that underwent resection surgery were significantly younger than those who did not (mean ± SD, 70.9 ± 11.4years vs 73.7 ± 12.8years, p < 0.001). Multivariable analyses revealed that both 90-day and 1-year mortality rates were higher in older patients that underwent resection surgery (90-day mortality OR 2.12 [95% CI 1.26-3.59], p < 0.005). However, there were no significant differences in postoperative intensive care, postoperative complications, reoperations, or readmissions. Elderly patients suffer increased postoperative mortality after resection surgery for colorectal cancer compared to younger individuals. Given the growing elderly population that will continue to require surgery for colorectal cancer, more efficient ways of determining and handling individual risk for older adults need to be implemented in clinical practice.

Validity assessment of the POLARS score tool in the prediction of post rectal cancer surgery LARS score in a population-based Swedish cohort

ObjectiveLow anterior resection syndrome (LARS) is one of the most common functional impairments after rectal cancer surgery with a high impact on quality of life. The Pre-Operative LARS score (POLARS)...

Incidence of adhesive small bowel obstruction after surgery for colorectal cancer in Sweden 2007-2016.

Population-based data on incidence and risk factors of adhesive small bowel obstruction (SBO) are limited. The aims of this study were to assess the risk of SBO and SBO surgery after bowel resection for colorectal cancer (CRC) and to assess whether this risk is modified by minimally invasive surgery (MIS) and radiotherapy in a retrospective national study. CRCBaSe, a nationwide register linkage originating from the Swedish Colorectal Cancer Register, was used to identify Stage I-III CRC patients who underwent resection in 2007-2016, with follow-up throughout 2017. Matched CRC-free comparators (1:6) were included as a reference of SBO and SBO surgery incidence. The association between MIS and preoperative radiotherapy and the incidence rate of SBO was evaluated in adjusted multivariable Cox regression models. Among 33 632 CRC patients and 198 649 comparators, the 5-year cumulative incidence of SBO and SBO surgery was 7.6% and 2.2% among patients and 0.6% and 0.2% among comparators, with death as a competing risk. In all patients, MIS was associated with a reduced incidence of SBO (hazard ratio [HR] 0.7, 95% CI 0.6-0.8) and SBO surgery (HR 0.5, 95% CI 0.3-0.7). In rectal cancer patients, radiotherapy was associated with an increased incidence of SBO (HR 1.6, 95% CI 1.4-1.8) and SBO surgery (HR 1.7, 95% CI 1.3-2.3). Colorectal cancer surgery is associated with a marked increase in risk of SBO, compared with the general population. The incidence is further increased if open surgery or radiotherapy is performed.

Tumour deposits in colon cancer predict recurrence and reduced survival in a nationwide population-based study.

Tumour deposits are suggested to impact prognosis in colon cancer negatively. This study assessed the impact of tumour deposits on oncological outcomes. Data from the Swedish Colorectal Cancer Registry for patients who underwent R0 abdominal surgery for TNM stage I-III colon cancer between 2011 and 2014 with 5-year follow-up were analysed with multivariable analysis. Patients were categorized for their tumour deposit status and compared for the local recurrence and distant metastasis rates and 5-year survivals (overall and relative). Subgroup analyses were performed according to the nodal disease status. Of 8146 stage I-III colon cancer patients who underwent R0 resection, 8014 patients were analysed (808 tumour deposits positive, 7206 tumour deposits negative). Patients with tumour deposits positive tumours had increased local recurrence and distant metastasis rates (7.2 versus 3.0 per cent; P < 0.001 and 33.9 versus 12.0 per cent; P < 0.001 respectively) and reduced 5-year overall and relative survival (56.8 per cent versus 74.9 per cent; P < 0.001 and 68.5 versus 92.6 per cent; P < 0.001 respectively). In multivariable analysis, tumour deposits moderately increased the risks of local recurrence and distant metastasis (hazard ratio 1.50, 95 per cent c.i. 1.09 to 2.07; P = 0.013 and HR 1.91, 95 per cent c.i. 1.64 to 2.23; P < 0.001 respectively) and worse 5-year overall and relative survival (hazard ratio 1.60, 95 per cent c.i. 1.40 to 1.82; P < 0.001 and excess hazard ratio 2.24, 95 per cent c.i. 1.81 to 2.78; P < 0.001 respectively). Subgroup analysis of N stages found that N1c patients had worse outcomes than N0 for distant metastasis and relative survival. For patients with lymph node metastases tumour deposits increased the risks of distant metastasis and worse overall and relative survival, except for N2b patients. Tumour deposits negatively impact the prognosis in colon cancer and must be considered when discussing adjuvant chemotherapy.

The modified Glasgow Prognostic Score indicates an increased risk of anastomotic leakage after anterior resection for rectal cancer

BackgroundPreoperative inflammation might cause and also be a marker for anastomotic leakage after anterior resection for rectal cancer. Available biomarker indices such as the modified Glasgow Prognostic Score (mGPS) or the C-reactive protein-to-albumin ratio (CAR) may be clinically useful for leakage assessment.MethodsPatients who underwent anterior resection for rectal cancer during 2014–2018 from a multicentre retrospective cohort were included. Data from the Swedish Colorectal Cancer registry and chart review at each hospital were collected. In a subset of patients, preoperative laboratory assessments were available, constituting the exposures mGPS and CAR. Anastomotic leakage within 12 months was the outcome. Causally oriented analyses were conducted with adjustment for confounding, as well as predictive models.ResultsA total of 418 patients were eligible for analysis. Most patients had mGPS = 0 (84.7%), while mGPS = 1 (10.8%) and mGPS = 2 (4.5%) were less common. mGPS = 2 (OR: 4.11; 95% CI: 1.69–10.03) seemed to confer anastomotic leakage, while this was not seen for mGPS = 1 (OR 1.09; 95% CI: 0.53–2.25). A cut off point of CAR > 0.36 might be indicative of leakage (OR 2.25; 95% CI: 1.21–4.19). Predictive modelling using mGPS rendered an area-under-the-curve of 0.73 (95% CI: 0.67–0.79) at most.DiscussionPreoperative inflammation seems to be involved in the development of anastomotic leakage after anterior resection for cancer. Inclusion into prediction models did not result in accurate leakage prediction, but high degrees of systemic inflammation might still be important in clinical decision-making.

Complete response rates in rectal cancer: Temporal changes over a decade in a population-based nationwide cohort

IntroductionIn the past decade many changes in neoadjuvant treatment for patients with rectal cancer have taken place and are expected to impact complete response rates. The aim of this study was to investigate the impact on pathological, and overall, complete response rates in a nationwide population-based cohort, in relation to changes in neoadjuvant treatment and the start of a Watch & Wait (WoW) study. Materials and methodsA nationwide register study using prospectively collected data from the Swedish Colorectal Cancer Register between 2009 and 2020. Patients with rectal cancer stage I-III with a ypT0N0 in the resected specimen after neoadjuvant treatment and clinical complete responders from the yearly inclusion data of the national WoW study were included. Temporal changes in pathological and overall complete response rates were analysed, and differences in neoadjuvant treatment regimens over time and per region were studied. ResultsBetween 2009 and 2020 the pathological complete response rate for rectal cancer remained similar (Mann-Kendall tau of 0.091, p = 0.68) while the overall complete response rate increased significantly from 3.0% to 9.6% (Mann-Kendall tau of 0.818, p < 0.001). The pathological complete response rate for patients receiving short course radiotherapy followed by chemotherapy was reduced by 50% after the introduction of the WoW study. ConclusionsDuring the studied time period the overall complete response rate increased significantly presumably due to changes in national neoadjuvant treatment regimens. Since the start of the national WoW study clinical complete response seem to partly replace pathological complete response.

Interval cancer after two rounds of a Swedish population-based screening program using gender-specific cut-off levels in fecal immunochemical test.

To evaluate interval cancer (IC) after two screening rounds of the Swedish population-based screening program of Stockholm-Gotland applying gender-specific cut-off levels in the fecal immunochemical test (FIT). All 60- to 69-year-olds invited to screening 2015-2019 were included. The cut-off level for a positive test was 40 µg/g in women and 80 µg/g in men. Screening-detected colorectal cancers (SD CRCs) and ICs were verified in the Swedish Colorectal Cancer Register, and the follow-up time was two years from invitation. The test sensitivity, the IC rate (ICs per 10,000 screening negatives) and the IC incidence (ICs per 100,000 person-years) relative to the background CRC incidence were assessed by gender and age. The FIT levels were compared in men and women for CRCs diagnosed within one year of the sample. In the second screening round, 229,187 were invited, and SD CRCs and ICs were diagnosed in 193 and 144, respectively. The IC rate was 8.9 (7.4-10.3) and test sensitivity 0.61 (0.55-0.66), and was similar in men and women. For two screening rounds, the IC rate was significantly higher in men than in women, but the IC incidence/ background CRC incidence was similar in both genders. The FIT levels in female participants with CRC were significantly lower overall, and in early-staged CRCs as compared to men, and proximal localization was more common in women. In multivariable analysis, FIT levels were significantly lower in proximal CRCs. Over two rounds, the IC incidence relative to the background CRC incidence was similar in men and women supporting a gender-specific screening strategy. The results could be explained by lower FIT levels in women due to proximal CRC localization.

Defunctioning stoma in anterior resection for rectal cancer does not impact anastomotic leakage: a national population-based cohort study

BackgroundAnterior resection (AR) is considered the gold standard for curative cancer treatment in the middle and upper rectum. The goal of the sphincter-preserving procedure, such as AR, is vulnerable to anastomotic leak (AL) complications. Defunctioning stoma (DS) became the protective measure against AL. Often a defunctioning loop-ileostomy is used, which is associated with substantial morbidity. However, not much is known if the routine use of DS reduces the overall incidence of AL.MethodsElective patients subjected to AR in 2007–2009 and 2016-18 were recruited from the Swedish colorectal cancer registry (SCRCR). Patient characteristics, including DS status and occurrence of AL, were analyzed. In addition, independent risk factors for AL were investigated by multivariable regression.ResultsThe statistical increase of DS from 71.6% in 2007–2009 to 76.7% in 2016–2018 did not impact the incidence of AL (9.2% and 8.2%), respectively. DLI was constructed in more than 35% of high-located tumors ≥ 11 cm from the anal verge. Multivariable analysis showed that male gender, ASA 3–4, BMI > 30 kg/m2, and neoadjuvant therapy were independent risk factors for AL.ConclusionRoutine DS did not decrease overall AL after AR. A selective decision algorithm for DS construction is needed to protect from AL and mitigate DS morbidities.

Impact of previous diverticulitis on 5-year survival and recurrence rates in patients with colorectal cancer

Background Diverticulitis and colorectal cancer (CRC) share epidemiological characteristics, but their relationship remains unknown. It is unclear if prognosis following CRC differ for patients with previous diverticulitis compared to those with sporadic cases and patients with inflammatory bowel disease or hereditary syndromes. Aim The aim was to determine 5-year survival and recurrence after colorectal cancer in patients with previous diverticulitis, inflammatory bowel disease and hereditary colorectal cancer compared to sporadic cases. Methods Patients <75 years of age diagnosed with colorectal cancer at Skåne University Hospital Malmö, Sweden, between January 1st 2012 and December 31st 2017 were identified through the Swedish colorectal cancer registry. Data was retrieved from the Swedish colorectal cancer registry and chart review. Five-year survival and recurrence in colorectal cancer patients with previous diverticulitis were compared to sporadic cases, inflammatory bowel disease associated and hereditary colorectal cancer. Results The study cohort comprised 1052 patients, 28 (2.7%) with previous diverticulitis, 26 (2.5%) IBD, 4 (1.3%) hereditary syndromes and 984 (93.5%) sporadic cases. Patients with a history of acute complicated diverticulitis had a significantly lower 5-year survival rate (61.1%) and higher recurrence rate (38.9%) compared to sporadic cases (87.5% and 18.8% respectively). Conclusion Patients with acute complicated diverticulitis had worse 5-year prognosis compared to sporadic cases. The results emphasize the importance of early detection of colorectal cancer in patients with acute complicated diverticulitis.

Preoperative Radiotherapy Decision-Tree for Rectal Cancer Patients: A Real-World Analysis Based on the Swedish Colorectal Cancer Registry

BackgroundThere are 3 widely used preoperative radiotherapy (RT) procedures in rectal cancer treatment including long-course RT (LRT), short-course RT with delayed surgery (SRTW), and short-course RT with immediate surgery (SRT). However, further evidence is required to determine which treatment option results in more optimal patient survival. MethodsThis Swedish Colorectal Cancer Registry-based retrospective study of real-world data included 7766 stage I–III rectal cancer patients, of which 2982, 1089, 763, and 2932 patients received no RT (NRT), LRT, SRTW, and SRT, respectively. The Kaplan-Meier survival curve and Cox proportional hazard multivariate model were used to identify potential risk factors and to examine the independent association of RT with patient survival after adjusting for baseline confounding factors. ResultsRT effects on survival differed by age and clinical T stage (cT) subgroups. Subsequent survival analysis by age and cT subgroups confirmed that patients ≥70 years old with cT4 benefited from any RT (P < .001, NRT as reference) and equally from any RT (P > .05 pairwise between RTs). In contrast, for cT3 patients ≥70 years, SRT and LRT were associated with better survival than SRTW (P < .001). In patients <70 years, LRT and SRTW had superior survival benefits in cT4 patients but inferior to SRT (P < .001); SRT was the only effective treatment in the cT3N+ subgroup (P = .032); patients with cT3N0 and <70 years did not benefit from any RT. ConclusionThis study suggests that preoperative RT strategies may have varying effects on the survival of rectal cancer patients, depending on their age and clinical stage.

OC-115 ABDOMINAL RECTUS MUSCLE THICKNESS AS A PREDICTOR FOR PARASTOMAL HERNIA

Abstract Aim To examine whether the dimensions of the abdominal rectus muscle (ARM) affect the risk of developing parastomal hernia (PSH). The hypothesis is that a thinner anteroposterior (AP) dimension of the ARM predisposes for PSH. Material &amp; Methods Retrospective cohort study of rectal cancer patients undergoing tumour resection and permanent colostomy creation in two Swedish healthcare regions during 2005–2017. Patients were identified from the nationwide Swedish Colorectal Cancer Registry. Measurements of ARM dimensions in the AP and latero-lateral (LL) planes were made on preoperative (before permanent colostomy creation) and postoperative (9–18 months post stoma creation) computerised tomography images. The ARM dimensions were analysed in a multivariate logistic regression model, considering known risk factors and potential confounders. Results Some 151 of the planned 200 patients have been included, of which 40% are female and 20% have a radiologically evident PSH at approximately one year postoperatively. Preliminary results from the multivariate model do not indicate that ARM thickness can predict the occurrence of PSH. Body mass index seems to be the only predictor in this material. The study is still including. Conclusions Preliminary results indicate that ARM thickness is not an independent risk factor for PSH development. Supplementary results will be presented.