Annika Sjövall

Detection of colorectal cancer (CRC) is mainly achieved by clinical assessment. As new treatments become available for metastatic CRC (MCRC), it is important to accurately identify these patients. To develop a predictive model for identifying MCRC in primary health care patients using diagnostic data analysed with machine learning. A case-control study utilising data on primary health care visits for 146 patients >18 years old diagnosed with MCRC in the Västra Götaland Region, Sweden during 2011, and 577 sex-, age, and primary health care centre-matched controls. Stochastic gradient boosting was used to construct a model for predicting the presence of MCRC based on diagnostic codes from primary health care consultations during the year before index (diagnosis) date and number of consultations. Variable importance was estimated using the normalised relative influence (NRI) score. Risks of having MCRC were calculated using odds ratios of marginal effects (OR_ME). The optimal model included 76 variables with non-zero influence, had an area under the curve of 76.5%, a sensitivity of 77.8%, and a specificity of 69.2%. The 10 most important variables had a combined NRI of 61.0%. Number of consultations during the year before index date had the highest NRI at 19.2%, with an OR_ME of 3.3. A machine learning method based on primary health care consultation frequency and diagnoses may be used to identify important variables for predicting presence of MCRC. Both primary health care consultations and associated diagnostic codes need to be taken into consideration.

Objective: To assess the performance of an algorithm for automated grading of surgery-related adverse events (AEs) according to Clavien-Dindo (C-D) classification. Background: Surgery-related AEs are common, lead to increased patient morbidity, and raise health care costs. Resource-intensive manual chart review is still standard, and, to our knowledge, algorithms using electronic health record (EHR) data to grade AEs according to C-D classification have not been explored. Methods: The algorithm was developed in a research database containing all EHR data of Karolinska University Hospital Stockholm and returns a C-D grade for each AE within 30 days. This raw score was used to grade the postoperative recovery of 1379 elective colorectal procedures according to C-D classification and Comprehensive Complication Index. Agreement with manual annotation of colorectal surgeon (gold standard) and research nurse (current practice) was assessed in a random sample of 399 procedures. Results: For the C-D classification, kappa was 0.77 (95% CI: 0.71 to 0.84) for algorithm versus surgeon and 0.74 (95% CI: 0.67 to 0.82) for algorithm versus nurse. The kappa value increased to 0.89 (95% CI: 0.84 to 0.95) after the correction of misclassified annotations by the surgeon. The intraclass correlation for Comprehensive Complication Index between algorithm and surgeon was 0.89 (95% CI: 0.87 to 0.91) after correction and 0.76 (95% CI: 0.71 to 0.80) for algorithm versus nurse. Conclusions: The performance of the algorithm motivates in our opinion implementation to real-time data under continuous scientific evaluation of the impact on AEs in different types of surgery. In the future, local EHR data could be used to enhance risk prediction with machine learning techniques.

AimThe study aimed to compare 5-year overall survival in a national cohort of patients undergoing curative abdominal resection for colon cancer by minimally invasive surgery (MIS) or by the open (OPEN) technique. MethodsAll patients diagnosed between 2010 and 2016 in Sweden with pathological Union International Contre le Cancer Stages I-III colon cancer localized in the caecum, ascending colon, hepatic flexure or sigmoid colon and those who underwent curative right sided hemicolectomy, sigmoid resection or high anterior resection by MIS or OPEN were included. Patients were identified in the Swedish Colorectal Cancer Registry from which all data were retrieved. The analyses were performed as intention-to-treat and the relationship between surgical technique (MIS or OPEN) and overall mortality within 5 years was analysed. For the primary research question a non-inferiority hypothesis was assumed with a statistical power of 90%, a one-side type I error of 2.5% and a non-inferiority margin of 2%. For the secondary analyses, multilevel survival regression models with the patients matched by propensity scores were employed, adjusted for patient- and tumour-related variables. ResultsA total of 11 605 pathological Union International Contre le Cancer Stages I-III patients were included with 3297 MIS (28.4%) and 8308 OPEN (71.6%) and were followed until 31 December 2020. The primary analysis demonstrated superiority for MIS compared to OPEN. The multilevel survival regression analyses confirmed that 5-year overall survival was higher in MIS with a hazard ratio of 0.874 (95% confidence interval 0.791-0.965), and if excluding pT4 the outcome was similar, with a hazard ratio of 0.847 (95% confidence interval 0.756-0.948). ConclusionThis observational study demonstrated that MIS was favourable to OPEN with regard to 5-year overall survival. These results support the use of laparoscopic colon cancer surgery in routine practice.

Background: Colorectal cancer management may require an ostomy formation; however, a stoma may negatively impact health-related quality of life (HRQoL). This study aimed to compare generic and stoma-specific HRQoL in patients with a permanent colostomy after rectal cancer across different countries. Method: A cross-sectional cohorts of patients with a colostomy after rectal cancer in Denmark, Sweden, Spain, the Netherlands, China, Portugal, Australia, Lithuania, Egypt, and Israel were invited to complete questionnaires regarding demographic and socioeconomic factors along with the Colostomy Impact (CI) score, European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) and five anchor questions assessing colostomy impact on HRQoL. The background characteristics of the cohorts from each country were compared and generic HRQoL was measured with the EORTC QLQ-C30 presented for the total cohort. Results were compared with normative data of reference European populations. The predictors of reduced HRQoL were investigated by multivariable logistic regression, including demographic and socioeconomic factors and stoma-related problems. Results: A total of 2557 patients were included. Response rates varied between 51–93 per cent. Mean time from stoma creation was 2.5–6.2 (range 1.1–39.2) years. A total of 25.8 per cent of patients reported that their colostomy impairs their HRQoL ‘some’/‘a lot’. This group had significantly unfavourable scores across all EORTC subscales compared with patients reporting ‘no’/‘a little’ impaired HRQoL. Generic HRQoL differed significantly between countries, but resembled the HRQoL of reference populations. Multivariable logistic regression showed that stoma dysfunction, including high CI score (OR 3.32), financial burden from the stoma (OR 1.98), unemployment (OR 2.74), being single/widowed (OR 1.35) and young age (OR 1.01 per year) predicted reduced stoma-related HRQoL. Conclusion: Overall HRQoL is preserved in patients with a colostomy after rectal cancer, but a quarter of the patients interviewed reported impaired HRQoL. Differences among several countries were reported and socioeconomic factors correlated with reduced quality of life.

High hospital volume has been shown associated with improved survival in patients with several cancers. The aim of this nationwide cohort study was to investigate whether hospital volume affects survival in patients with locally advanced colonic cancer. All patients with non-metastatic locally advanced colonic cancer diagnosed between 2007 and 2017 in Sweden were included. Tertiles of annual hospital volume of locally advanced colonic cancer were analysed and 5-year overall and colonic cancer-specific survival were calculated with the Kaplan–Meier method. HRs comparing all-cause and colonic cancer-specific mortality rates were estimated using Cox models adjusted for potential confounders (age, sex, year of diagnosis, co-morbidity, elective/emergency resection, and university hospital) and mediators (preoperative multidisciplinary team assessment, neoadjuvant chemotherapy, radical resection, and surgical experience). A total of 5241 patients were included with a mean follow-up of 2.7–2.8 years for low- and high-volume hospitals. The number of patients older than 79 years were 569 (32.3 per cent), 495 (29.9 per cent), and 482 (26.4 per cent) for low-, medium- and high-volume hospitals respectively. The 3-year overall survival was 68 per cent, 60 per cent and 58 per cent for high-, medium- and low-volume hospitals, respectively (P < 0.001 from log rank test). High volume hospitals were associated with reduced all-cause and colon cancer-specific mortality after adjustments for potential confounders (HR 0.76, 95 per cent CI 0.62 to 0.93 and HR 0.73, 95 per cent CI 0.59 to 0.91, respectively). The effect remained after inclusion of potential mediators. High hospital volume is associated with reduced mortality in patients with locally advanced colonic cancer.

Aim: A proportion of patients treated for colorectal cancer have impaired quality of life (QoL) but it is uncertain if the level of QoL differs from the corresponding background population. This population‐based cohort study aimed to evaluate health‐related QoL in colorectal cancer patients and compare their QoL with that of a Swedish reference population.Methods: Patients who underwent surgery for colorectal cancer Stages I–III in the Stockholm–Gotland region in 2013–2015 received the European Organization for Research and Treatment of Cancer (EORTC) QLQ‐C30 and the QLQ‐CR29 questionnaires and the low anterior resection syndrome score, 1 year after surgery. Patient and tumour data were collected from the Swedish Colorectal Cancer Registry. The patient cohort was matched to a Swedish reference population regarding EORTC QLQ‐C30. Global QoL was compared to the reference population and a patient group with impaired QoL was defined. Detailed patient‐reported outcomes were analysed in relation to global QoL in the patient cohort.Results: A total of 925 patients returned the questionnaires and 358 patients (38.70%) reported a clinically relevant impaired global QoL compared to the reference population. Patients with impaired QoL reported clinically relevant and statistically significantly more complaints regarding bowel habits, pain and anxiety. After adjustment for sex, age and stoma, anxiety was the strongest predictor for impaired QoL, with OR 6.797 (95% CI 4.677–9.879).Conclusion: A substantial proportion of patients treated for colorectal cancer have impaired global QoL. This impairment is strongly associated with several physical symptoms and anxiety.

Purpose Stoma-related problems are known to be important to patients and potentially affect everyday life. The prevalence of stoma-related problems in rectal cancer survivors remains undetermined. This study aimed to examine aspects of life with a long-term stoma, stoma management, and stoma-related problems and explore the impact of stoma-related problems on daily life. Methods In total, 2262 patients from 5 European countries completed a multidimensional survey. Stoma-related problems were assessed using the Colostomy Impact score. Multivariable regression analysis, after adjusting for potential confounding factors, provided odds ratio (OR) and 95% confidence intervals (CI) for stoma-related problems’ association with restrictions in daily life. Results The 2262 rectal cancer survivors completed the questionnaire at a median of 5.4 years (interquartile range 3.8–7.6) after stoma formation. In the total sample, leakage (58%) and troublesome odour (55%) were most prevalent followed by skin problems (27%) and pain (21%). Stoma-related problems were more prevalent in patients with parastomal bulging. A total of 431 (19%) reported feeling restricted in daily activities in life with a stoma. Leakage, odour, skin problems, stool consistency, and frequent appliance changes were significantly associated with restrictions in daily life. The highest risk of experiencing restrictions was seen for patients having odour (OR 2.74 [95% CI: 1.99–3.78]) more than once a week and skin problems (OR 1.77 [95% CI: 1.38–2.27]). Conclusion In this large cohort with rectal cancer, stoma-related problems were highly prevalent and impacted daily life. Supportive care strategies should entail outreach to patients with a long-term stoma.

Aim The Stockholm‐Gotland Regional Cancer Plan was launched in 2012 to improve cancer care. Implementation of a personal contact nurse (CN), an Individual Written Care Plan (IWCP) and a Standardized Care Pathway (SCP) were introduced. The aim of the current study was to evaluate whether these efforts have resulted in an improved patient experience in patients treated for colorectal cancer. Method Patients treated with bowel resection for colorectal cancer in the Stockholm‐Gotland region during Jan 1^st 2013 to Dec 31^st 2017 were identified through the Swedish Colorectal Cancer Registry. Six to eight months postoperatively the patients received a Patient Reported Experience questionnaire. Patients were classified as “satisfied” or “not satisfied”. Results The questionnaire was sent to 4465 patients and 3154 (70.64%) responded. The proportion of patients assigned a CN increased over time (79.84% to 88.44%) and so did the proportion of patients receiving an IWCP (39.36% to 70.00%). The waiting times were significantly shortened during the study period. In multivariable analysis, access to CN and IWCP were independently associated with increased patient satisfaction (OR 3.03, 95% CI 2.28‐4.02 and OR 1.64, 95% CI 1.38‐1.94). Patients with long waiting time were significantly less satisfied than patients with short waiting time (OR 0.72, CI 0.60‐0.88). Conclusion Implementation of CN, IWCP and SCP has been successful, measured by a higher proportion of patients getting access to these assets and shortened waiting times. This has led to an improved patient experience in patients treated for colorectal cancer in the Stockholm‐Gotland region.

Aim: An anastomotic leak after surgery for colon cancer is a recognized complication but how it may adversely affect long‐term survival is less clear because data are scarce. The aim of the study was to investigate the long‐term impact of Grade C anastomotic leak in a large, population‐based cohort.Method: Data on patients undergoing resection for Stage I–III colon cancer between 2008 and 2012 were collected from the Swedish, Norwegian and Danish Colorectal Cancer Registries. Overall relative survival and conditional 5‐year relative survival, under the condition of surviving 1 year, were calculated for all patients and stratified by stage of disease.Results: A total of 22 985 patients were analysed. Anastomotic leak occurred in 849 patients (3.7%). Five‐year relative survival in patients with anastomotic leak was 64.7% compared with 87.0% for patients with no leak (P < 0.001). Five‐year relative survival among the patients who survived the first year was 88.6% vs 81.3% (P = 0.003). Stratification by cancer stage showed that anastomotic leak was significantly associated with decreased relative survival in patients with Stage III disease (P = 0.001), but not in patients with Stage I or II (P = 0.950 and 0.247, respectively).Conclusion: Anastomotic leak after surgery for Stage III colon cancer was associated with significantly decreased long‐term relative survival.