Existing data sources for clinical epidemiology: the Danish National Pathology Registry and Data Bank

Metastatic risk in clear cell renal cell carcinoma: a tool incorporating sex, size, and grade

OBJECTIVE

To identify predictors of metastases, estimate the proportion of metastatic clear cell renal cell carcinoma (ccRCC) cases according to these predictors, and subsequently create a risk table showing the absolute difference in metastasis proportion for each 10 mm increase in tumour size.

PATIENTS AND METHODS

Patients diagnosed with histopathological confirmed ccRCC in 2010-2018 in Denmark identified in the nationwide Danish Multidisciplinary Renal Cancer Group (DaRenCa) Study-3. Association between diagnostic variables and metastases were assessed with logistic regression analyses. Proportion of cases with metastases were assess based on tumour sizes using a logistic regression model.

RESULTS

The study included 2109 cases with non-metastatic ccRCC at diagnosis and 450 cases with metastatic ccRCC. Multivariable logistic regression analyses found sex, tumour size and grade were associated with metastatic ccRCC, whereas age was not. The proportion of cases with metastasis increased with larger tumours sizes and higher grade. As an example, the proportion of metastases in female cases with tumour size of 40 mm was 2.9% (95% confidence interval [CI] 1.7-4.8%) in Grade 1 and 16% (95% CI 12-22%) in cases with Grade 4. Comparable numbers in cases with a tumour size of 70 mm were 6.6% (95% CI 4.0-11%) and 31% (95% CI 25-38). The absolute increase in the proportion of cases with metastases with a 10 mm increase in size was <2% for tumours <40 mm and Grade 1-2. In contrast, cases with tumour sizes >50 mm and/or Grade 3-4 had a moderate (2-<4%) to high (≥4%) absolute increase in the proportion of cases with metastases with each 10 mm increase.

CONCLUSION

The risk table presented offers a valuable tool for discussing the risk of progression to metastases in patients under expected management for ccRCC, enabling clinicians to make more informed, evidence-based decisions.

Statin use and risk of breast cancer among women with benign breast disease: a Danish nationwide cohort study

BACKGROUND

Statins have been suggested to protect against breast cancer risk, but the observational evidence is inconclusive. We examined the association between statin use and breast cancer incidence among women at higher risk of breast cancer due to a history of benign breast disease (BBD).

METHODS

Using Danish registries, we identified cancer-free women aged ≥50 years during 1996-2018 with a history of BBD and no prior statin prescriptions. Using Cox regression, we estimated multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for invasive breast cancer through 2020 with time-varying statin use defined according to continuity, duration, and intensity (estimated average daily dose), derived from prescription data.

RESULTS

Among 111,550 women, 7629 were diagnosed with breast cancer during median follow-up of 12.2 years. Overall statin use was not associated with breast cancer incidence (adjusted HR = 0.99; 95% CI, 0.93-1.06), with similar associations observed according to continuity and duration of use. However, long-term (≥10 years), high-intensity statin use was associated with a reduced HR of 0.75 (95% CI, 0.60-0.96).

CONCLUSIONS

Our findings did not indicate an association for overall statin use with breast cancer incidence among women with BBD. The inverse association with long-term, high-dose statin use requires further evaluation.

Improving cervical cancer screening participation by introducing HPV vaginal self-sampling to women living with HIV in Denmark- a pilot study

BACKGROUND

Cervical cancer, despite being largely preventable through vaccination and screening, continues to pose a significant global health challenge. Women living with HIV (WLWH) are at a six-fold higher risk of developing cervical cancer, primarily due to persistent infection with high-risk HPV (hrHPV). While effective screening methods have the potential to reduce this risk, WLWH remain inadequately screened. The aims of this pilot study were fourfold: To estimate the proportion of WLWH who are not screened according to WHO guidelines; to establish the proportion of WLWH who accepted the self-sampling offer; to estimate the hrHPV DNA prevalence; and to estimate the compliance to follow-up among women with a hrHPV-positive vaginal self-sample.

METHODS

This single-centre, pilot study was conducted from February to May 2022 at the Department of Infectious Diseases, Aarhus University Hospital, Central Denmark Region. Eligible women were contacted by phone and invited to participate. Participants were provided with a self-sampling kit (Evalyn® Brush) and detailed instructions. The collected samples were analysed for hrHPV DNA using the COBAS® 4800 assay. Demographic, clinical, and screening history data were obtained from medical records and the Danish Pathology Databank.

RESULTS

Of the 100 eligible participants, 50% (n = 50) accepted the offer of self-sampling, and 80% (n = 40/50) returned their samples for analysis. The prevalence of hrHPV among these women was 25% (n = 10/40). Follow-up compliance among hrHPV-positive women was 40% (n = 4/10). The analysis revealed that 41% (n = 41/100) of WLWH had not been screened in accordance with WHO guidelines, and 39% (n = 16/41) of the women had never undergone screening. No significant differences were observed in demographic or clinical characteristics between participants and non-participants.

CONCLUSIONS

Vaginal hrHPV self-sampling was acceptable and feasible for WLWH, with high return rates but suboptimal follow-up compliance. Enhancing participation and adherence is crucial for effective cervical cancer prevention. Larger studies are needed to validate these findings and optimize screening strategies.

TRIAL REGISTRATION

The Central Denmark Region Committee on Health Research Ethics deemed this study as a quality improvement study on the 9th of November 2021 (request approval j.no: 204/1-10-72-274-21).

CLINICAL TRIAL NUMBER

Not applicable.

Cancer recurrence risk with bDMARD treatment in patients with rheumatoid arthritis and a history of cancer: a nationwide Danish register-based cohort study

OBJECTIVE

To investigate the risk of cancer recurrence in patients with rheumatoid arthritis (RA) and a prior solid cancer in remission treated with biological disease-modifying antirheumatic drugs (bDMARDs) compared with those who received only conventional synthetic DMARDs (csDMARDs).

METHODS

Nationwide registry-based cohort study of Danish patients with RA and one of the six algorithm-specific solid cancers in remission (breast, colorectal, melanoma, bladder, endometrial and lung) who initiated treatment with a bDMARD or a csDMARD. Three bDMARD exposure groups were defined according to the type(s) of bDMARD initiated: (1) any bDMARD, (2) tumour necrosis factor inhibitors (TNFi) and (3) rituximab. Patients were identified in Danish Rheumatology Quality Register and followed for cancer recurrence from 2002 to 2021 using validated cancer-specific recurrence algorithms. Inverse probability of treatment weighting and weighted cause-specific Cox models were used to calculate HRs for cancer recurrence in each bDMARD exposure group compared with a csDMARD-treated group.

RESULTS

Among 720 unique patients with RA and an algorithm-specific solid cancer in remission, 170 any bDMARD, 81 TNFi, 99 rituximab and 651 csDMARD initiators were identified. No statistically significant increased HRs for cancer recurrence were found with any type of bDMARD 0.92 (95% CI 0.38 to 1.73), TNFi 1.10 (95% CI 0.21 to 3.16) or rituximab 0.94 (95% CI 0.32 to 2.11). Also, no increased HRs were shown for breast cancer recurrence specifically.

CONCLUSION

No indications of increased cancer recurrence risk were found for bDMARDs as used in clinical practice in patients with RA and a solid cancer in remission when compared with csDMARD treatment.

Cumulative incidence of macular edema in non-infectious uveitis indicates an early therapeutic window

PURPOSE

Uveitis-associated macular edema (UME) is a significant cause of visual impairment in non-infectious uveitis (NIU). However, the UME incidence remains unclear. Here, we evaluated the cumulative incidence of UME.

METHODS

Medical records of patients registered with a uveitis diagnosis code between 2010 and2024 were assessed to validate uveitis diagnoses of the patient registry of the North Denmark Region, a region of 600 000 inhabitants. Positive predictive values (PPV) were calculated for uveitis diagnosis and subtypes. The data from medical records were used to estimate prevalence, incidence and cumulative incidence of UME. The group differences were analysed by chi-squared test and cox proportional-hazards model.

RESULTS

A total of 1476 medical records were reviewed. The PPV for a uveitis diagnosis was 92.2% (95% CI: 90.7-93.5) and 88.4% (95% Cl: 86.8-90.0) for uveitis subtypes. Among 1218 patients with NIU, 6.9% had UME at referral. During follow-up, 8.3% of the NIU patients developed UME with an incidence rate of 1.4 per 100 person-years (95% CI: 1.3-1.7) and a cumulative incidence of 10.7% (95% CI: 8.5-13.5). A higher incidence of UME was observed for patients with bilateral uveitis, systemic disease, intermediate uveitis, posterior uveitis and panuveitis (p < 0.001). A substantial increase in the cumulative incidence of UME was observed in the first 2 years post-referral.

CONCLUSION

The high PPV supported the registry's reliability for uveitis research. UME was frequently present at the first uveitis clinic visit. NIU patients were at heightened risk of UME within the first 2 years after referral, indicating an early time window with a critical need for inflammation management.

Circulating Tumor DNA in Addition to Fecal Immunochemical Test in a Dual-Test Colorectal Cancer Screening Approach

BACKGROUND

Early detection is paramount when reducing incidence and mortality of colorectal cancer (CRC). Current population-based screening programs primarily use fecal immunochemical test (FIT) to allocate individuals for colonoscopy although low specificity challenges colonoscopy capacities. We aimed to assess the potential of circulating tumor (ct)DNA markers for early CRC detection in a dual-test CRC screening approach among FIT positive individuals.

METHODS

Plasma samples from 774 FIT positive (≥100 ng Hemoglobin/mL) individuals from the Danish CRC screening program were analyzed for hypermethylated DNA in the genes Branched Chain Amino-acid Transaminase 1 (BCAT1), Ikaros-Family Zinc Finger transcription 1 (IKZF1), and Interferon Regulator Factor 4 (IRF4). Multivariate logistic regression models were generated adding the ctDNA markers and age to the FIT value. The dual-test approach was benchmarked to FIT at specific thresholds.

RESULTS

The dual-test approach improved CRC detection compared to the FIT alone (AUC of 87.2 [95% CI, 82.9-91.4] vs AUC of 72.5 [95% CI, 67.0-77.9]). This was also seen when adding advanced adenomas to the outcome resulting in AUCs of 71.8 [95% CI, 67.8-75.8] for the dual-test approach compared to 65.5 [95% CI, 61.3-69.7] for the FIT model alone. Benchmarking the dual-test approach at FIT cut-offs between 100 and 600 ng Hb/mL showed a potential for either reducing the colonoscopy requirement by up to 56% or increasing CRC detection by up to 28%.

CONCLUSIONS

As increasing FIT cutoff will decrease CRC detection rate, application of the ctDNA panel can increase the sensitivity and specificity in a dual-test approach among asymptomatic individuals.

Temporal trends in incidence and mortality of colorectal cancer in Denmark from 2007 to 2022

Colorectal cancer (CRC) is the third most common cancer in the Western world and represents a significant burden on healthcare systems worldwide. We aimed to describe temporal trends in incidence, tumor characteristics, and survival for patients with CRC in a nationwide, population-based cohort in Denmark. We used population-based Danish healthcare registries to study all patients diagnosed with CRC from 2007 to 2022. Exactly 76,955 people in Denmark were diagnosed with CRC from 2007 to 2022. ASIRs were relatively stable from 2007 to 2013, with an ASIR of 65.8 per 100,000 for colon cancer and 32 per 100,000 for rectal cancer. In 2014, an increase in incidence was observed (79.8 per 100,000 for colon cancer and 37.4 per 100,000 for rectal cancer), followed by a decline in later years. Median survival times were 4.1 (IQR: 0.8 to 14.1) years for patients diagnosed between 2007 and 2010, 5.3 (IQR: 1.1 to -) years for patients diagnosed from 2011 to 2013, and 7.6 (IQR: 1.7 to -) years for patients diagnosed from 2014 to 2017. The assessment of mutational and molecular profiles increased consistently throughout the study period. We observed an initial increase in CRC incidence in 2014, corresponding with the implementation of the national screening program, followed by a subsequent decline. In recent years, the incidence has dropped below pre-screening levels. Additionally, the increasing use of molecular and mutational profiling reflects the growing complexity and multidisciplinary nature of CRC management.

The Danish Lymphoid Cancer Research (DALY-CARE) Data Resource: The Basis for Developing Data-Driven Hematology

Background

Lymphoid-lineage cancers (LC; International Classification of Diseases, 10th edition [ICD10] C81.x-C90.x, C91.1-C91.9, C95.1, C95.7, C95.9, D47.2, D47.9B, and E85.8A) share many epidemiological and clinical features, which favor meta-learning when developing medical artificial intelligence (mAI). However, access to large, shared datasets is largely missing and limits mAI research.

Aim

Creating a large-scale data repository for patients with LC to develop data-driven hematology.

Methods

We gathered electronic health data and created open-source processing pipelines to create a comprehensive data resource for Danish LC Research (DALY-CARE) approved for epidemiological, molecular, and data-driven research.

Results

We included all Danish adults registered with LC diagnoses since 2002 (n=65,774) and combined 10 nationwide registers, electronic health records (EHR), and laboratory data on a high-powered cloud-computer to develop a secure research environment. Among other, data include treatments (ie 21,750 cytoreductive treatment plans, 21.3M outpatient prescriptions, and 12.7M in-hospital administrations), biochemical analyses (77.3M), comorbidity (14.8M ICD10 codes), pathology codes (4.5M), treatment procedures (8.3M), surgical procedures (1.0M), radiological examinations (3.3M), vital signs (18.3M values), and survival data. We herein describe the data infrastructure and exemplify how DALY-CARE has been used for molecular studies, real-world evidence to evaluate the efficacy of care, and mAI deployed directly into EHR systems.

Conclusion

The DALY-CARE data resource allows for the development of near real-time decision-support tools and extrapolation of clinical trial results to clinical practice, thereby improving care for patients with LC while facilitating streamlining of health data infrastructure across cohorts and medical specialties.

Clinicopathological characteristics, long-term prognosis and follow-up recommendations of primary and secondary cutaneous angiosarcoma: A Danish nationwide population-based cohort study

BACKGROUND

The prognostic impact of subclassifying tumors as primary and secondary cutaneous angiosarcoma (cAS) in terms of the risk of local recurrence, metastasis, disease-specific mortality, and overall survival has not been extensively investigated in previous studies. This study aimed to characterize the clinicopathological features and estimate the 2-, 5-, and 10-year rates of local recurrence, metastasis, disease-specific death, and overall survival for patients with primary and secondary cAS, and to propose a follow-up recommendation for these patients.

METHODS

All Danish patients diagnosed with cAS between 2000 and 2023 were included. The prognosis was estimated using age- and sex-standardized stratified cause-specific Cox-regression with all-cause mortality as a competing risk.

RESULTS

A total of 192 patients were included, comprising 99 patients with primary cAS and 93 with secondary cAS. The 5-year local recurrence rate was similar between primary (42 %) and secondary cAS (39 %). However, patients with primary cAS exhibited a higher 5-year rate of metastasis (50 %) compared to those with secondary cAS (33 %). Similarly, the 5-year disease-specific mortality was substantially higher in patients with primary cAS (57 %) compared to secondary cAS (35 %). Correspondingly, the 5-year overall survival rate was low in both primary (32 %) and secondary cAS (49 %).

CONCLUSION

Primary cAS is associated with poorer 5-year outcomes of metastasis, disease-specific death, and overall survival compared with secondary cAS. Follow-up could be limited to 5 years, as >95 % of the relapses occurred within this period and may include clinical examinations and local MRI to detect local recurrences, and cross-sectional imaging to detect regional and distant metastases.

Risk of and Mortality After Acute Kidney Injury Following Cancer Treatment: A Cohort Study

BACKGROUND

Acute kidney injury (AKI) can be a severe complication in cancer patients. However, uncertainty remains regarding the risk of and prognosis after AKI following cancer treatments. We therefore aimed to examine the risk of and mortality after AKI following a wide range of specific cancer treatments, including surgical procedures, anticancer drugs, and hematopoietic stem cell transplantations (HSCTs).

METHODS

We conducted a nationwide population-based cohort study. We included adult patients receiving cancer treatment in Denmark from 2010 to 2024. We calculated the risk of AKI within 7 days after surgeries, 1 year after initiation of anticancer drugs, and 100 days after HSCTs. Furthermore, we examined the 1-year mortality in patients with and without AKI following cancer treatment.

RESULTS

We identified 357,870 cancer patients. The 7-day risk of AKI after surgery ranged from 0.3% (breast cancer surgery) to 68.9% (radical nephrectomy in kidney cancer) while the 1-year risk following anticancer drug treatment ranged from 3.5% (cyclophosphamide in breast cancer) to 79.3% (all drugs in acute lymphatic leukemia). The 100-day AKI risk following HSCT ranged from 20.7% (multiple myeloma) to 81.8% (leukemia). For most treatments, AKI was associated with a higher 1-year hazard ratio and risk of death, with exceptions including radical nephrectomy in kidney cancer.

CONCLUSION

In conclusion, several cancer treatments were associated with a high risk of AKI, and AKI was associated with increased mortality in most treatments. These findings highlight the prognostic value of assessing kidney function following specific cancer treatments in clinical practice.

High rate of persistent HPV detection after diagnostic cervical excision in older screen-positive women

INTRODUCTION

Diagnostic work-up of older women with a positive cervical cancer screening test is often challenging due to incomplete visualization of the transformation zone. To reduce the risk of missing disease, a diagnostic cervical excision may be performed. However, little is known on treatment efficacy and post-treatment surveillance for older women. We aimed to investigate the proportion of women testing negative for human papillomavirus (HPV) following a diagnostic cervical excision due to an abnormal screening test.

MATERIAL AND METHODS

We conducted a prospective cohort study on women aged ≥45 years who were referred for colposcopy due to an abnormal screening test between March 2019 and June 2021. All women had incomplete visualization of the transformation zone and underwent colposcopy and a diagnostic cervical excision at the first visit. Women were followed from date of excision until January 30, 2023. Follow-up data was retrieved from the Danish Pathology Databank, and baseline characteristics were obtained from medical records. Cox regression was used on interval-censored data to estimate crude and adjusted hazard ratios for a negative HPV test after cervical excision, stratified by histology and age.

RESULTS

A total of 100 women underwent a diagnostic cervical excision and had at least one HPV test during follow-up. Median age was 67.4 years, and median follow-up time was 2.9 years. At the end of follow-up, 70% tested HPV negative. Women with cervical intraepithelial neoplasia grade two or worse in their excision specimen were more likely to test HPV negative at the first test after cervical excision compared to women with less than cervical intraepithelial neoplasia grade two, however, not statistically significant (adjusted hazard ratio 1.69, 95% CI 0.92-3.10). Women aged 65-84 years were less likely to test HPV negative compared to women <65 years (adjusted hazard ratio 0.49, 95% CI 0.28-0.87).

CONCLUSIONS

In older women undergoing a diagnostic cervical excision, 70% tested HPV negative after 2.9 years, leaving 30% with persistent HPV positivity. More studies are needed to determine the risks associated with continued HPV positivity in the absence of high-grade disease. Furthermore, given the absence of specific guidelines, the optimal surveillance frequency remains unknown.

Risk and prognosis of posttransplant lymphoproliferative disease in Epstein-Barr virus-seronegative kidney transplant recipients - an observational cohort study from Norway and western Denmark

Posttransplant lymphoproliferative disorder (PTLD) poses a serious challenge in kidney transplant recipients. Epstein-Barr virus (EBV)-seronegative recipients have a significantly increased risk of PTLD, but few studies have investigated risk factors for PTLD in EBV-seronegative recipients in the current era of immunosuppression. This cohort study from Norway and western Denmark included first-time kidney transplant recipients between 2007 and 2021 and estimated the cumulative incidence, risk, and prognosis of PTLD. In total, 80 of 5084 recipients developed biopsy-proven PTLD (median follow-up of 6.8 years). Two-year cumulative incidence of PTLD was 7.3% in EBV-seronegative adults and 14.1% in EBV-seronegative children. The age-adjusted hazard ratio (HR) for PTLD was 30.7 (95% CI, 13.9-67.9) in EBV-seronegative vs EBV-seropositive adults and 5.4 (95% CI, 1.1-26.9) in children. Recipients receiving induction therapy with antithymocyte globulin had an increased risk of PTLD (HR, 4.4; 95% CI, 1.8-10.6), while rituximab induction was associated with a lower risk of PTLD (HR, 0.20; 95% CI, 0.03-1.49). The age-adjusted mortality rate was higher in EBV-seronegative recipients with vs without PTLD (HR, 3.3; 95% CI, 1.3-8.3). In conclusion, the risk of PTLD in EBV-seronegative kidney transplant recipients is high in the contemporary era of immunosuppression. Induction therapy should be carefully considered in this high-risk population.

Ovarian sex cord-stromal cell tumors and the risk of sex hormone-sensitive cancers

BACKGROUND

Sex cord-stromal cell tumors are rare ovarian tumors. Some sex cord-stromal cell tumors secrete hormones that originate from the ovarian sex or stromal cells. Previous studies have indicated an increased risk for breast and endometrial cancers. However, these studies focused only on the sex cord-stromal cell tumor-subtype of adult granulosa cell tumors, and the estimates stemmed from selected cohorts and lacked a well-described cohort, making it difficult to adjust for possible confounders.

OBJECTIVE

We examined the incidence of other primary hormone-sensitive cancers and compared their risk with that in a matched cohort of women without sex cord-stromal cell tumors.

STUDY DESIGN

This nested cohort study evaluated women diagnosed with sex cord-stromal cell tumors. We established a cohort of women diagnosed with sex cord-stromal cell tumors using Systematized Medical Nomenclature for Medicine codes from the Danish Pathology Register. Sex cord-stromal cell tumors diagnoses were considered valid if the primary diagnosis was established at a tertiary referral center or confirmed by at least 2 pathologists. A 1:10 matched control group matched by birth year was selected from national registries. Variables for the follow-up of cases and controls were drawn from national registries and included assessment of the rates of breast, ovarian, and endometrial cancer, hormone use, Charlson Comorbidity Index, and sociodemographics. Hazard ratios for cancer rates were calculated using multivariate Cox proportional hazards models with sex cord-stromal cell tumor exposure estimated in early and delayed models to capture cancer rates over time. The standardized incidence ratios for very rare sex cord-stromal cell tumors were determined using a log-linear Poisson model.

RESULTS

Among the 1516 tumors with Systematized Medical Nomenclature for Medicine codes for sex cord-stromal cell tumors, 1387 met the inclusion criteria after pathologic chart review. The majority had benign tumors, primarily thecoma or fibrothecomas (66%), and 26% had adult granulosa cell tumors. Increased rates of breast cancer were found among patients with thecomas (hazard ratio, 1.2; 95% confidence interval, 1.0-1.4). In the analysis of all sex cord-stromal cell tumors combined, an increased rate of synchronous endometrial cancer was found (hazard ratio, 3.3; 95% confidence interval, 2.7-4.1). In the subgroup analysis, malignant and benign sex cord-stromal cell tumors showed significantly higher hazard ratios for synchronous endometrial cancer, notably adult granulosa cell tumors (hazard ratio, 10.7; 95% confidence interval, 5.7-20.1). In the model that assessed the rates of endometrial cancer 2 months after surgical removal of the sex cord-stromal cell tumor, no increased rates were found. Sertoli cell tumors were associated with an increased incidence of breast cancer (standardized incidence ratio, 18.9; 95% confidence interval, 2.7-134). Both Sertoli and Leydig cell tumors were associated with a higher incidence of synchronous endometrial cancer with standardized incidence ratios of 41.4 (95% confidence interval, 10.4-166) and 44.9 (95% confidence interval, 18.7-108), respectively.

CONCLUSION

Women with sex cord-stromal cell tumors have an increased rate of synchronous endometrial cancer, and women with benign sex cord-stromal cell tumors have an increased rate of synchronous ovarian cancer. A marginally increased rate of breast cancer has been observed in women with thecomas. There was no increase in the rate of breast cancer among women with adult granulosa cell tumors. It is recommended that women diagnosed with hormone-secreting sex cord-stromal cell tumors and additional risk factors for endometrial cancer (abnormal uterine bleeding and/or abnormal endometrial thickness) should undergo an endometrial biopsy to assess for the presence of cancer.

Incidence, characteristics, and comorbidities of a complete unselected Danish cohort of patients with thymic epithelial tumors

BACKGROUND AND PURPOSE

We report the incidence, characteristics, and comorbidities of the complete unselected Danish cohort of patients with thymic epitheliums (TETs), which may serve as evidence for guiding treatment, surveillance, and counselling of TET patients.

PATIENTS AND METHODS

All patients diagnosed with TETs from January 1st, 2015, to December 31st, 2020, were identified using the Danish Pathology Data Registry. Data on patient characteristics, comorbidities, and tumor histology were collected from electronic medical records available for all patients.

RESULTS

The cohort consisted of 283 patients with a mean age of 64 years (SD: 12). The crude rate was 8.2/1,000,000 TETs annually, thus higher than the age-standardized rates of 4.8/1,000,000 in the WHO World Standard Population and 6.1/1,000,000 in the European Standard Population. Thymomas were diagnosed in 240 patients (85%) (9% type A, 31% AB, 18% B1, 26% B2, 6% B3, 5% micronodular, 0.4% metaplastic, and 5% of unspecified subtype), thymic carcinomas in 39 patients (14%), and thymic neuroendocrine tumors in 4 patients (1.4%). Tumors in Tumour, Node, Metastasis (TNM) stage I were diagnosed in 181 patients (64%) and were mostly thymomas (72%). Prior to TET diagnosis, 91 (32%) patients presented with autoimmune disorders (19% myasthenia gravis) and 82 patients (29%) had at least one cancer diagnosis.

INTERPRETATION

We found a higher incidence of TETs in Denmark than in previous European population-based studies, while reporting a similar distribution of histological types and tumor stages. Furthermore, we found an increased prevalence of autoimmune disorders and cancers in the cohort before TET diagnosis compared to the general population.

Prior Appendectomy Is Associated With a Milder Clinical Course in Crohn's Disease: A Nationwide Population-based Cohort Study

BACKGROUND

Appendectomy may affect the clinical course of Crohn's disease (CD), but rigorous evidence is sparse and contradicting. The aim of this study was to examine the association between appendectomy and the clinical course of CD.

METHODS

All patients diagnosed with CD in Denmark in the period from 1977 to 2017 were identified from the Danish National Patient Registry. Patients with appendectomy were matched with up to 10 comparators with CD and no appendectomy; and rates of CD-related hospital admissions were compared between CD patients with and without appendectomy using incidence rate ratios (IRRs). We used stratified Cox regression analysis to calculate adjusted hazard ratios (aHRs) of initiating treatment with biologics or undergoing intestinal resections.

RESULTS

In all, 21 189 CD patients (1936 with appendectomy and 19 253 without) were identified and followed for a median of 13.6 years. Crohn's disease patients who had undergone appendectomy experienced a lower rate of CD-related hospital admissions (appendectomy before CD: IRR = 0.83; 95% confidence interval [CI], 0.81-0.85; appendectomy after CD: IRR = 0.85; 95% CI, 0.81-0.88) compared with CD patients without appendectomy. For patients with appendectomy before CD diagnosis, the rate of initiating biologics was lower compared with CD patients with no appendectomy (aHR1-<5 years = 0.61; 95% CI, 0.46-0.81; aHR5-<10 years 0.47; 95% CI, 0.33-0.66; aHR10-20 years = 0.61; 95% CI, 0.47-0.79), as was the risk of undergoing colorectal resections (aHR1-<5 years = 0.94; 95% CI, 0.77-1.15; aHR5-<10 years 0.63; 95% CI, 0.47-0.85; aHR10-20 years = 0.75; 95% CI, 0.54-1.04). Rates of small bowel resections were comparable for CD patients with or without appendectomy prior to CD. Appendectomy performed after CD did not influence the rate of initiating treatment with biologics or undergoing intestinal resections.

CONCLUSION

The clinical course of CD is milder for those who have previously undergone appendectomy.

Prevalence and incidence of mastocytosis in adults: a Danish nationwide register study

INTRODUCTION

Mastocytosis is a group of rare heterogeneous diseases with a prevalence previously found to be 10-23 per 100,000 persons. More awareness and improvements in the diagnostic methods in later years have led to more patients being diagnosed. Here, we set out to present the prevalence and incidence rate of mastocytosis among the adult Danish population. By merging data from the Danish National Patient Register, the Danish Pathology Register and the Danish Cancer Register we included all adult patients (≥ 18 years) diagnosed with mastocytosis in Denmark prior to 2022. A cohort of 1,594 patients with mastocytosis was identified. The prevalence of mastocytosis was 27.43 per 100,000 persons (95% confidence interval [CI]: 25.95-28.96) as of January 1, 2022, and the 25-year average incidence rate between 1997 and 2021 was 1.21 per 100,000 persons (95%CI: 1.02-1.40) with an increasing incidence rate since 2002. We found a higher prevalence of mastocytosis among adults in the Danish population than previously reported, and an increasing incidence rate during the last 20 years. Increased awareness of the disease and better diagnostic methods most likely contributed to this.

Genetic variants and social benefit receipt in premenopausal women with breast cancer treated with docetaxel: a Danish population-based cohort study

PURPOSE

Breast cancer patients' need for social benefits may increase following taxane-based chemotherapy, due to long-lasting side effects. Specific single nucleotide polymorphisms (SNPs) may mediate such side effects. We investigated the association between SNPs related to taxane metabolism, transport, toxicity, or DNA and neural repair, and receipt of social benefits.

METHODS

From the Danish Breast Cancer Group, we identified premenopausal women diagnosed with stage I-III breast cancer during 2007-2011 and treated with docetaxel-based chemotherapy. We genotyped 21 SNPs from archived breast tumors using TaqMan assays. We ascertained social benefit payments from 1 year before to 5 years after diagnosis, using nationwide, administrative registry data. For each week, we categorized women as receiving health-related benefits (including sick leave and disability pension), labor market-related benefits (including unemployment benefits), or as being self-supporting. We computed rate ratios (RRs) of social benefit receipt for variant carriers (heterozygotes plus homozygotes) vs. non-carriers, using negative binominal regression with robust variance estimation.

RESULTS

Among 2430 women, 12% received health-related benefits before diagnosis, 80% at diagnosis, and ~ 24% 2 to 5 years after diagnosis. Labor market-related benefits were uncommon (3-6%). All RRs were near-null and/or imprecise.

CONCLUSION

We found no clinically meaningful impact of the selected SNPs on social benefit receipt among premenopausal breast cancer survivors treated with docetaxel.

Recurrent Laryngeal Papillomatosis in Denmark from 1994 to 2021: A Nationwide Register Study

OBJECTIVES

The aim of this study is to describe the incidence and demographics of laryngeal papillomatosis (LP) in Denmark, including sex and age distribution, recurrence rates, and HPV subtypes, using a new method of register identification.

METHODS

The data were extracted from the Danish Pathology Data Bank using SNOMED codes instead of the usual method using ICD codes from the Danish National Health Register. The derived pathology records were manually verified by three medical doctors. The study period was 1994-2021. Patients were categorized according to age as either juvenile-onset RRP (JoRRP) if <18 years or adult-onset RRP (AoRRP) if 18 years or older.

RESULTS

We identified 1819 RRP patients (JoRRP: 56; AoRRP:1763). The overall incidence per 100,000 inhabitants were 0.17 for JoRRP and 1.45 for AoRRP. The vast majority (72%) of the patients were male, but there was no significant difference in age at onset of RRP or recurrence rates between the sexes. Children below 3 years of age had the highest recurrence probability. Extracting data using SNOMED codes resulted in a positive predictive value of 99% regarding total number of biopsies and 98% regarding individuals. The incidence decreased throughout the study period.

CONCLUSION

Comparable incidence and recurrence rates of RRP were found between Denmark and Norway. In this study, the Danish Pathology Register was found to be a highly valuable method for identifying LP patients. The effect of the nationwide HPV vaccination program can be evaluated using this method as the vaccinated cohort is starting to grow older and reproduce.

LEVEL OF EVIDENCE

Retrospective registry-based national cohort study, 3 Laryngoscope, 134:5047-5053, 2024.

Mismatch Repair Status and Surgical Outcomes in Localized Colorectal Cancer: A Nationwide Cohort Study

Objective

This study examined the association between deficient mismatch repair (dMMR) versus proficient MMR (pMMR) status and overall survival and disease-free survival in patients with localized colorectal cancer.

Background

Several distinctions exist between patients with dMMR and pMMR colorectal cancer. However, the impact on prognosis is yet to be investigated in large-scale cohort studies.

Methods

In this cohort study, we included patients who underwent curative-intent surgery for localized colorectal cancer between 2009 and 2020. Patients were identified in the Danish Colorectal Cancer Group database and patient-level data were extracted from 6 registry databases. After inclusion, patients with dMMR status were matched 1:1 to patients with pMMR status using an estimated propensity score.

Results

After matching, 5994 patients were included. The patients had a median age of 74 years and a median follow-up of 4.1 years. There was no significant association between mismatch repair (MMR) status and overall survival (hazard ratio, 0.91; 95% confidence interval [CI], 0.81-1.03) or disease-free survival (hazard ratio, 0.89; 95% CI, 0.78-1.01). However, the restricted 5-year mean disease-free survival time, calculated due to violation of the proportional hazards assumption, showed a significant absolute difference of 0.13 years (95% CI, 0.03-0.23; P = 0.01) in favor of the dMMR group.

Conclusions

No significant association with overall survival was found according to MMR status. dMMR status was, however, found to be associated with marginally improved disease-free survival compared to pMMR status in patients with localized colorectal cancer undergoing curative-intent surgery.

Comparing budesonide treatment in eosinophilic esophagitis: a specialized center cohort versus a population-based cohort

OBJECTIVE

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease. The budesonide orodispersible tablet (BOT) is recommended as second-line treatment according to the Danish guideline. This study aimed to compare potential treatment disparities before BOT initiation, follow-up practices, clinico-histologic remission rates during BOT treatment, and adherence to the national guideline between the highly specialized EoE-Cph cohort and the population-based DanEoE cohort.

MATERIAL AND METHODS

This cohort study compared 65 adult patients from the EoE-Cph cohort with 65 patients from the DanEoE cohort. All patients were diagnosed between 2015-2021. The diagnosis of EoE was defined according to the AGREE consensus. Data were extracted manually from medical records and registries.

RESULTS

In the EoE-Cph cohort, 88% were prescribed proton pump inhibitors (PPIs) before started on BOT compared to 100% in the DanEoE cohort (p = 0.0035). Symptomatic follow-up occurred in 89% of EoE-Cph patients compared to 97% of DanEoE patients after BOT treatment (p = 0.0841). No difference was found between patients who underwent histologic follow-up after topical steroid treatment (83% versus 82%, p = 0.8162). Complete clinico-histologic remission was frequently observed, and no significant difference was observed between the two cohorts (67% versus 80%, p =0.1789). One out of four patients had conflicting symptomatic and histological responses.

CONCLUSIONS

This study did not provide conclusive evidence favoring the treatment of EoE patients exclusively at highly specialized EoE centers. However, the authors acknowledge that further evidence is necessary before considering changes in clinical practice. Conflicting treatment responses, and discontinuation of treatment due to side effects remains a notable concern.

Data Resource Profile: The Danish National Hospital Medicine Register

PURPOSE

The Danish National Hospital Medicine Register (SMR) was established in 2018 to centralize and standardize medication use data across Danish hospitals. This task was previously managed by individual hospital registration systems across the five regions. This initiative addresses the need for a unified, detailed understanding of hospital medication use to monitor healthcare delivery, improve patient outcomes, and support research.

METHODS

The SMR has comprehensive coverage of medication use in hospitals in Denmark, offering a national overview that was previously missing. It features high-quality data, with efforts to ensure completeness and accuracy. The data collected encompasses key categories such as types of medications, doses, administration times and practices, and specific treatment indications. The SMR facilitates collaboration among Danish regional health authorities and national health agencies, enhancing decision-making and planning across the regions.

RESULTS

The establishment of the SMR has provided a centralized and standardized database for medication use across Danish hospitals. This unification replaces the previously fragmented systems, allowing for better monitoring of healthcare delivery and supporting improvements in patient outcomes and research.

CONCLUSION

The upcoming version of the SMR will include data on dispensed outpatient medications, covering most medication use across all hospitals. This expansion will further enhance the register's utility for health authorities, clinicians, and researchers by providing a more comprehensive understanding of medication use in Denmark.

Adherence to recommended follow-up in opportunistic versus non-opportunistic cervical screening: a registry-based cohort study from Denmark

AIM

Organised cervical screening programmes often allow for opportunistic screening. Previous studies have shown that adherence to follow-up protocols after cervical screening is poor. This study aims to investigate if non-adherence to recommended screening intervals - that is, opportunistic screening, is associated with adherence to follow-up after non-negative cervical screening.

METHODS

Using national registries we included 42,399 Danish women with a non-negative screening result from 2015 to 2017. Non-adherence was divided into insufficient and excessive follow-up. We calculated relative risks (RRs) of adherence to follow-up among different groups of opportunistically screened women, representing both too frequent and delayed screening participation, compared with non-opportunistically screened women.

RESULTS

Compared with non-opportunistically screened women, opportunistically screened women who were delayed 1-3 years on their screening schedule had a higher risk of no follow-up (RR 1.99) and insufficient follow-up (RR 1.10). Women who were delayed 3-7 years on their screening also had a higher risk of no follow-up (RR 1.92). Women who attended screening up to 6 months too early had a higher risk of insufficient follow-up (RR 1.08) as well as excessive follow-up (RR 1.39). Finally, women screened more than 6 months too early had a higher risk of all deviations, but most pronounced was the risk of excessive follow-up (RR 1.67).

CONCLUSIONS

We found a higher risk of insufficient follow-up among women delayed in their screening schedule, and a higher risk of excessive follow-up among those with frequent screening. Screening participation behaviour seems to transfer to follow-up adherence. This underscores the important role of general practitioners in acting as gatekeepers in cervical screening follow-up.

Screening participants with inflammatory bowel disease or high colorectal cancer risk in Denmark: a cohort study

Individuals with inflammatory bowel disease (IBC) and high-risk individuals are advised to discuss participation with their doctor and not to participate in colorectal cancer (CRC) screening. Yet a substantial proportion still participate in the Danish faecal immunochemical test (FIT) screening and have a higher positive FIT rate than the average-risk population. We estimated the risk of false-positive screening among individuals with inflammatory bowel disease and high-risk individuals to improve recommendations regarding screening participation. We included 71,871 FIT-positive participants (2014-2017) who had a subsequent colonoscopy within 3 months. Screening outcome within 180 days was established by using registers. We determined that 26,591 of the included participants had a false-positive screening. Participants with IBC or high CRC risk had a significantly higher risk of getting a false-positive screening than the average risk population, resulting in too many screening-related colonoscopies being performed among these individuals, indicating a need to update the screening protocols.

Infections and their prognostic significance before diagnosis of chronic lymphocytic leukemia, non-Hodgkin lymphoma, or multiple myeloma

BACKGROUND

Immunodeficiency is a shared feature of B cell malignancies. The risk of infections and their prognostic significance after diagnosis are well characterized, but, conversely, less is known about prediagnostic infections in these domains.

METHODS

In matched case-control analyzes, using Danish nationwide registers, we assessed the rate of prediagnostic infections in chronic lymphocytic leukemia (CLL), diffuse large B cell lymphoma (DLBCL), multiple myeloma (MM), follicular lymphoma (FL), marginal zone lymphoma (MZL), and lymphoplasmacytic lymphoma (LPL). Survival analyzes of data from clinical registers were then used to determine the effect of infections in the year preceding diagnosis on overall survival. To yield results for as many patients as possible, antimicrobial prescriptions were used as surrogates for infections.

RESULTS

The nationwide and clinical registers comprised 30,389 patients, accumulating 213,649 antimicrobial prescriptions, and 18,560 patients accumulating 107,268 prescriptions, respectively. The relative risk of infections was increased up to 15 years prior to diagnosis of malignancy and markedly increased in the year just prior to diagnosis. More than two antimicrobials within one year prior to diagnosis were associated with significantly shorter overall survival, independently of known prognostic factors.

CONCLUSION

Patients with B cell-derived malignancies exhibit marked immunodeficiency several years prior to diagnosis such that different disease subtypes demonstrate both overlapping and distinct trends in infection risk preceding diagnosis. Moreover, multiple infections within the year preceding diagnosis are independently associated with shorter overall survival for all the examined malignancies.

Cervical cancer screening integrated in routine clinical care of women with HIV

OBJECTIVE

To evaluate if integrated cervical cancer screening (CCS) for women with HIV (WWH) in routine HIV care resulted in increased adherence to screening, and to describe the prevalence of human papillomavirus (HPV)-specific genotypes and the incidence of cellular abnormalities.

DESIGN

Cohort study.

METHODS

WWH who accepted the offer of combined CCS and HIV care (group 1), WWH who declined the offer (group 2), and WWH not offered CCS within HIV care (group 3) between 2013 and 2019 were included. Data was collected from The Danish HIV Cohort Study and The Danish Pathology Data Bank. Adherence to the CCS program was defined as fulfilled if WWH were screened annually.

RESULTS

A total of 804 WWH were included. WWH who accepted CCS within HIV care (group 1; n  = 218) had significantly higher adherence to screening in all study years 22-99% compared with the WWH who declined CCS (group 2; n  = 232) 10-16% and WWH who were not invited for CCS (group 3; n  = 354) 11-25%. There was no significant difference in the prevalence of HPV-specific genotypes and incidence of cellular abnormalities among the three groups.

CONCLUSION

Integrating CCS for WWH in routine HIV care resulted in higher adherence to the CCS guidelines. Combined services thereby represent an opportunity to engage WWH in HIV care into preventive services.

The validity of pathology codes for biopsy-confirmed kidney disease in the Danish National Patobank

Background

This study validates the application of Systematized Nomenclature of Medicine second edition (SNOMED II) codes used to describe medical kidney biopsies in Denmark in encoded form, aiming to support robust epidemiological research on the causes, treatments and prognosis of kidney diseases.

Methods

Kidney biopsy reports from 1 January 1998 to 31 December 2018 were randomly extracted from the Danish National Patobank, using SNOMED codes. A 5% sample was selected, and nephrologists assessed the corresponding medical records, assigning each case the applied clinical diagnoses. Sensitivity, specificity, positive predictive values (PPV), negative predictive values and Cohen's kappa coefficient for the retrieved SNOMED codes were calculated.

Results

A total of 613 kidney biopsies were included. The primary clinical disease groups were glomerular disease (n = 368), tubulointerstitial disease (n = 67), renal vascular disease (n = 51), diabetic nephropathy (n = 51) and various renal disorders (n = 40). Several SNOMED codes were used to describe each clinical disease group and PPV for the combined SNOMED codes were high for glomerular disease (94%), diabetic nephropathy (85%) and systemic diseases affecting the kidney (96%). Conversely, tubulointerstitial disease (62%), renal vascular disease (60%) and other renal disorders (17%) showed lower PPV.

Conclusions

SNOMED codes have a high PPV for glomerular diseases, diabetic nephropathy and systemic diseases affecting the kidney, in which they could be applied for future epidemiological research.

Biopsy-verified vulvar lichen sclerosus: Incidence trends 1997-2022 and increased risk of vulvar squamous precancer and squamous cell carcinoma

Population-based data on the epidemiology of vulvar lichen sclerosus (LS) are sparse and only few prospective studies have investigated the malignant potential of the disease. We used the nationwide Danish Pathology Registry to first assess the incidence of biopsy-verified vulvar LS in the period 1997-2022 and second to examine the incidence of vulvar high-grade squamous precancer and squamous cell carcinoma (SCC) in women with biopsy-verified vulvar LS (1978-2019) compared with that expected in the general female population. For the latter aim, we computed standardized incidence ratios (SIRs) with 95% confidence intervals (CIs). During our study period, the age-standardized incidence rate of vulvar LS increased from 5.0 (1997-1998) to 35.7 (2021-2022) per 100,000 person-years. Compared with the general female population, women with biopsy-verified vulvar LS had significantly increased rates of vulvar high-grade squamous precancer (SIR = 8.5; 95% CI: 7.2-10.0) and SCC (SIR = 16.2; 95% CI: 14.2-18.4). The SIRs of vulvar high-grade squamous precancer and SCC did not vary substantially according to length of follow-up. This nationwide and population-based study shows a 7-fold increase in the incidence of biopsy-verified vulvar LS since 1997. Data also show that women with biopsy-verified vulvar LS have 8.5 and 16 times higher than expected incidence of vulvar high-grade squamous precancer and SCC, respectively. The substantially increased incidence of vulvar high-grade squamous precancer and SCC following LS is important in relation to the clinical management and follow-up of LS patients.

Cervical intraepithelial neoplasia and fecundability: a prospective cohort study

STUDY QUESTION

Is cervical intraepithelial neoplasia (CIN) associated with reduced fecundability, defined as the probability of conceiving per menstrual cycle?

SUMMARY ANSWER

Overall, we observed no meaningful association between CIN and fecundability, regardless of surgical status, although a recent diagnosis of moderate or severe CIN might be associated with slightly reduced fecundability for 2 years after diagnosis.

WHAT IS KNOWN ALREADY

About 15% of couples experience infertility. Few studies have examined the influence of CIN on fertility, and the results have been inconsistent. No study has investigated the association between fecundability and pathologist-reported CIN diagnoses, particularly with respect to the recency of the specific CIN diagnoses.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 9586 women trying to conceive. The women were enrolled from 1 June 2007 to 3 February 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women were invited to complete a baseline questionnaire and bimonthly follow-up questionnaires for up to 12 months or until pregnancy occurred. Data on cervical cytologies and biopsies were retrieved from The National Pathology Registry (DNPR), which holds records of all cervical specimens examined in Denmark. Women were categorized based on their most severe diagnosis of CIN: no lesion, other cervical changes, mild CIN (CIN1), or moderate/severe CIN (CIN2+) with or without surgery. To investigate the association between CIN and fecundability, we computed fecundability ratios (FR) and 95% confidence intervals (CI) using a proportional probabilities regression model. We adjusted for age at study entry, partner age, body mass index, smoking status, timing of intercourse, parity, education, number of sexual partners, and household income.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with no lesion, the adjusted FRs (95% CI) for the association between CIN and fecundability were: other cervical lesions, 0.97 (0.91-1.04); CIN1, 1.04 (0.96-1.13); CIN2+ no surgery, 1.00 (0.82-1.22); and CIN2+ with surgery 0.99 (0.89-1.10). The FRs (95% CI) for a recent diagnosis (<2 years) of CIN were 0.98 (0.86-1.11) for other cervical lesions; 1.13 (0.99-1.29) for CIN1; 0.89 (0.62-1.26) for CIN2+ no surgery and 0.91 (0.75-1.10) for CIN2+ with surgery compared with the no lesion group.

LIMITATIONS, REASONS FOR CAUTION

In the analyses, we adjusted for several covariates related to the women. However, we had little information on the male partners which could lead to unmeasured confounding as fecundability is a couple-based measure of fertility. Furthermore, a CIN diagnosis may not be constant as it may regress or progress spontaneously; therefore, it is possible that we have misclassified some women, especially women categorized as having normal cells or CIN1.

WIDER IMPLICATIONS OF THE FINDINGS

Our results contribute important knowledge to women who are concerned about their future fertility after receiving a CIN diagnosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by The Danish Cancer Society (R167-A11036-17-S2). The overall cohorts were funded by the National Institute of Child Health and Human Development (R01-HD086742 and R03-HD094117). The authors report no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Effect of surgery versus chemotherapy in pancreatic cancer patients: a target trial emulation

BACKGROUND

To estimate the causal effect of surgery vs chemotherapy on survival in patients with T1-3NxM0 pancreatic cancer in a rigorous framework addressing selection bias and immortal time bias.

METHODS

We used population-based Danish health-care registries to conduct a cohort study emulating a hypothetical randomized trial to estimate the absolute difference in survival, comparing surgery with chemotherapy. We included pancreatic cancer patients diagnosed during 2008-2021. Exposure was surgery or chemotherapy initiated within a 16-week grace period after diagnosis. At the time of diagnosis, data of each patient were duplicated; one copy was assigned to the surgery protocol, and one copy to the chemotherapy protocol of the hypothetical trial. Copies were censored when the assigned treatment deviated from the observed treatment. To account for informative censoring, uncensored patients were weighted according to confounders. For comparison, we also applied a more conventional analysis using propensity score-based inverse probability weighting.

RESULTS

We included 1744 patients with a median age of 68 years: 73.6% underwent surgery, and 18.6% had chemotherapy without surgery; 7.8% received no treatment. The 3-year survival was 39.7% (95% confidence interval [CI] = 36.7% to 42.6%) after surgery and 22.7% (95% CI = 17.7% to 28.4%) after chemotherapy, corresponding to an absolute difference of 17.0% (95% CI = 10.8% to 23.1%). In the conventional survival analysis, this difference was 23.0% (95% CI = 17.0% to 29.0%).

CONCLUSION

Surgery was superior to chemotherapy in achieving long-term survival for pancreatic cancer. The difference comparing surgery and chemotherapy was substantially smaller when using the clone-censor-weight approach than conventional survival analysis.

Improving diagnostic of cervical dysplasia among postmenopausal women aged ≥50 years using local vaginal oestrogen treatment prior to colposcopy: study protocol for a multicentre randomised controlled trial (the IDEAL study)

INTRODUCTION

Colposcopy is the most important diagnostic tool to detect cervical precancerous lesions and thereby prevention of cervical cancer. Due to age-dependent changes of the cervix, colposcopy is challenging in postmenopausal women, as the majority will have a non-visible transformation zone, resulting in increased risk of missing disease, a diagnostic cone biopsy and prolonged follow-up with repeated colposcopies. This study will be among the first to investigate, if treatment with vaginal oestrogen prior to colposcopy will improve the colposcopy performance, to ensure accurate and timely diagnosis of precancerous cervical lesions among postmenopausal women.

METHODS AND ANALYSIS

A randomised blinded controlled multicentre study. Enrolment will be performed at gynaecology departments in Central Denmark Region and Region of Southern Denmark. A total of 150 postmenopausal women aged ≥50 years referred for colposcopy due to abnormal cervical screening results will be randomised 1:1 to either pretreatment with vaginal application of Vagifem 30 µg or placebo once a day for 14 days prior to colposcopy. The primary outcome will be to compare the percentage of women in the two groups with a visible transformation zone at colposcopy, and biopsies representative of the transformation zone. Secondary outcomes will be the proportion of detected cervical intraepithelial neoplasia grade 2 or higher in the cervical biopsies; the proportion of diagnostics cone biopsies; the patients' report on possible side effects and compliance to the pretreatment.

ETHICS AND DISSEMINATION

The study has been approved by the Central Denmark Region Committee on Biomedical Research Ethics (1-10-72-34-22), the Central Denmark Regions' Research Unit (1-16-02-72-22) and The Danish Health Authority (Danish Medicine Agency; 2022015030). The study's EudraCT number is (1-23-456; 2022-000269-42) and it is registered on www.

CLINICALTRIALS

gov. The local Good Clinical Practice (GCP) unit will supervise and monitor the study closely before, during and after the study period. Findings will be disseminated in peer-reviewed scientific journals and presented in relevant conferences.

TRIAL REGISTRATION NUMBER

NCT05283421.

Appendectomy and Risk of Advanced Colorectal Neoplasia in Inflammatory Bowel Disease: A Nationwide Population-based Cohort Study

BACKGROUND

The aim of this study was to examine the association between appendectomy and advanced colorectal neoplasia (aCRN) in patients with inflammatory bowel disease (IBD).

METHODS

Inflammatory bowel disease patients diagnosed in Denmark in the period 1977 to 2017 were identified from the Danish National Patient Registry. Inflammatory bowel disease patients who underwent appendectomy were matched with up to 10 IBD patients without appendectomy and followed until aCRN, death, or emigration. Absolute risks of aCRN were calculated, treating death and bowel resections as competing risks. Stratified Cox regression was used to calculate adjusted hazard ratios (aHRs) of aCRN, comparing IBD patients with appendectomy to IBD patients without appendectomy.

RESULTS

We identified 3789 IBD patients with appendectomy and 37 676 IBD patients without appendectomy. A total of 573 patients (1.4%) developed aCRN, with an absolute risk of aCRN at 20 years of 4.9% (95% confidence interval [CI], 2.9%-7.7%) for ulcerative colitis (UC) patients with appendectomy after UC diagnosis compared with 2.8% (95% CI, 2.3%-3.3%) for UC patients without appendectomy. Appendectomy after UC was associated with an increased rate of aCRN 5 to 10 years (aHR, 2.5; 95% CI, 1.1-5.5) and 10 to 20 years after appendectomy (aHR, 2.3; 95% CI, 1.0-5.5). Appendectomy prior to UC diagnosis was not associated with an increased rate of aCRN, and Crohn's disease was not associated with the rate of aCRN, regardless of timing or histological diagnosis of the appendix specimen.

CONCLUSIONS

Although appendectomy may have a positive effect on the clinical course of UC, our study suggests that this may come at the expense of a higher risk of aCRN.

Incidence of late recurrence and second primary cancers 5-10 years after non-metastatic colorectal cancer

The fraction of patients who are cancer-free survivors 5 years after curative-intended surgery for colorectal cancer (CRC) is increasing, suggesting that extending surveillance beyond 5 years may be indicated. Here we estimate the incidence of late recurrence, metachronous CRC, and second primary cancers 5-10 years postoperative. All patients resected for UICC stage I-III CRC in Denmark through 2004-2013 were identified. Through individual-level linkage of nationwide health registry data, recurrence status was determined using a validated algorithm. Cancer-free survivors 5 years after surgery, were included. Cumulative incidence functions (CIF) of late recurrence, metachronous CRC, and second primary cancer 5-10 years postoperative were constructed. Subdistribution hazards ratios (sHR) were computed using Fine-Gray regression. Among 8883 patients, 370 developed late recurrence (5-10-year CIF = 4.1%, 95%CI: 3.7%-4.6%), 270 metachronous CRC (5-10-year CIF = 3.0%, 95%CI: 2.7%-3.4%), and 635 a second primary cancer (5-10-year CIF = 7.2%, 95%CI: 6.7%-7.7%). The risk of late recurrence was reduced for patients operated in 2009-2013 compared to 2004-2008 (2.9% vs. 5.6%, sHR = 0.52, 95% CI: 0.42-0.65). The risk of metachronous CRC was likewise reduced from 4.1% to 2.1% (sHR = 0.50, 95%CI: 0.39-0.65). While the risk of second primary cancer did not change between 2009-2013 and 2004-2008 (7.1% vs. 7.1%, sHR = 0.98, 95% CI: 0.84-1.15). Using nation-wide 10-year follow-up data, we document that the incidences of late recurrence and metachronous CRC are low and decreasing from 2004 to 2013. Thus, despite increasing numbers of long-term cancer survivors, the data do not advocate for extending CRC-specific surveillance beyond 5 years.

Use of Bladder-Related Medication in Non-Muscle Invasive Bladder Cancer Patients

Repeated transurethral bladder resections (TURBs) and instillation treatments in non-muscle invasive bladder cancer (NMIBC) might influence bladder function and, therefore, quality of life. Bladder-related medication is a surrogate marker of compromised bladder function. The objective was to investigate whether TURBs and adjuvant instillation therapy are associated with the use of anticholinergics, β3-agonists, and cystitis-relevant antibiotics. We divided all Danish patients diagnosed with primary NMIBC during 2002-2017 registered in the Danish National Patient Registry (DNPR) based on TURB-load within the first five years from diagnosis (1 TURB, 2-4 TURBs, ≥5 TURBs). Instillation therapy with either mitomycin C (MMC) or bacillus Calmette-Guerin vaccine (BCG) was independent exposure (yes or no). We included 17,774 patients; 76% men, median age: 70 years (IQR: 63, 77). Patients exposed to ≥5 TURBs had a higher risk of using bladder-relaxing medication than patients exposed to 1 TURB, HR = 4.01 [3.33; 4.83], and higher risk of cystitis, HR = 2.27 [2.05; 2.51]. BCG-exposed patients had a higher risk of bladder-relaxing medication use compared to non-exposed, HR = 1.92 [1.69; 2.18], and a higher risk of cystitis, HR = 1.39 [1.31; 1.48]. Repeated TURBs have the highest impact on bladder function. Adjuvant instillation therapy is also associated with the use of bladder-related medication.

Lung cancer patients with anaplastic lymphoma kinase rearrangement lose affiliation with labor market at diagnosis

Aim: The main purpose of the present study was to investigate the labor market affiliation of ALK+ NSCLC patients in long-term treatment as well as overall survival and incidence/prevalence. Materials & methods: Nationwide retrospective study of all patients with ALK+ NSCLC in Denmark diagnosed between 2012 and 2018. Results: During the study period ALK+ NSCLC patients had a median overall survival of 44.0 months and a 7.8-fold increase in disease prevalence. Six months prior to diagnosis, 81% of ALK+ NSCLC patients ≤60 years of age were employed. At the end of the 18-month follow-up period, 36% were employed. Conclusion: ALK+ NSCLC patients have prolonged survival following diagnosis, but a large fraction of patients lose affiliation with the labor market.

Prognostic factors for relapse in patients with clinical stage I testicular non-seminoma: A nationwide, population-based cohort study

BACKGROUND

Approximately 30% of patients with clinical stage I non-seminoma (CSI-NS) relapse. Current risk stratification is based on lymphovascular invasion (LVI) alone. The extent to which additional tumor characteristics can improve risk prediction remains unclear.

OBJECTIVE

To determine the most important prognostic factors for relapse in CSI-NS patients.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study including all patients with CSI-NS diagnosed in Denmark between 2013 and 2018 with follow-up until 2022. Patients were identified in the prospective Danish Testicular Cancer database. By linkage to the Danish National Pathology Registry, histological slides from the orchiectomy specimens were retrieved.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Histological slides were reviewed blinded to the clinical outcome. Clinical data were obtained from medical records. The association between prespecified potential prognostic factors and relapse was assessed using Cox regression analysis. Model performance was evaluated by discrimination (Harrell's C-index) and calibration.

RESULTS

Of 453 patients included, 139 patients (30.6%) relapsed during a median follow-up of 6.3 years. Tumor invasion into the hilar soft tissue of the testicular hilum, tumor size, LVI and embryonal carcinoma were independent predictors of relapse. The estimated 5-year risk of relapse ranged from < 5% to > 85%, depending on the number of risk factors. After internal model validation, the model had an overall concordance statistic of 0.75. Model calibration was excellent.

CONCLUSION AND RELEVANCE

The identified prognostic factors provide a much more accurate risk stratification than current clinical practice, potentially aiding clinical decision-making.

Societal costs and survival of patients with biopsy-verified non-alcoholic steatohepatitis: Danish nationwide register-based study

INTRODUCTION AND OBJECTIVES

Studies on the societal burden of patients with biopsy-confirmed non-alcoholic fatty liver disease (NAFLD) are sparse. This study examined this question, comparing NAFLD with matched reference groups.

MATERIALS AND METHODS

Nationwide Danish healthcare registers were used to include all patients (≥18 years) diagnosed with biopsy-verified NAFLD (1997-2021). Patients were classified as having simple steatosis or non-alcoholic steatohepatitis (NASH) with or without cirrhosis, and all matched with liver-disease free reference groups. Healthcare costs and labour market outcomes were compared from 5 years before to 11 years after diagnosis. Patients were followed for 25 years to analyse risk of disability insurance and death.

RESULTS

3,712 patients with biopsy-verified NASH (n = 1,030), simple steatosis (n = 1,540) or cirrhosis (n = 1,142) were identified. The average total costs in the year leading up to diagnosis was 4.1-fold higher for NASH patients than the reference group (EUR 6,318), 6.2-fold higher for cirrhosis patients and 3.1-fold higher for simple steatosis patients. In NASH, outpatient hospital contacts were responsible for 49 % of the excess costs (EUR 3,121). NASH patients had statistically significantly lower income than their reference group as early as five years before diagnosis until nine years after diagnosis, and markedly higher risk of becoming disability insurance recipients (HR: 4.37; 95 % CI: 3.17-6.02) and of death (HR: 2.42; 95 % CI: 1.80-3.25).

CONCLUSIONS

NASH, simple steatosis and cirrhosis are all associated with substantial costs for the individual and the society with excess healthcare costs and poorer labour market outcomes.

Work Disability and Return to Work After Treatment for Acute Lymphoblastic Leukemia: A Danish Nationwide Cohort Study

Purpose

Most adult patients diagnosed with acute lymphoblastic leukemia (ALL) are below retirement age. The overall survival of patients with ALL has improved with implementation of high intensity pediatric-inspired treatment protocols. However, this treatment comes with a risk of long-term complications, which could affect the ability to work. The aim of this study was to investigate the risk of disability pension (DP) and return to work (RTW) for patients with ALL.

Patients and Methods

Patients aged 18-60 years diagnosed with ALL between 2005 and 2019 were identified in the Danish National Acute Leukemia Registry. Each patient was matched with five comparators from the general population on birth year, sex, and Charlson Comorbidity Index. The Aalen-Johansen estimator was used to calculate the cumulative risk of DP for patients and comparators from index date (defined as 1 year after diagnosis) with competing events (transplantation or relapse, death, retirement pension, or early retirement pension). Differences in cumulative incidences were calculated using Gray's test. RTW was calculated as proportions one, three, and five years after the index date for patients holding a job before diagnosis.

Results

A total of 154 patients with ALL and 770 matched comparators were included. The 5-year cumulative risk of DP was increased fivefold for patients with ALL compared with the general population. RTW was 41.7%, 65.7%, and 60.7% one, three, and five years after the index date, respectively.

Conclusion

The risk of DP in patients with ALL increased significantly compared with the general population. Five years after the index date, RTW was 60.7% for patients with ALL.

Speed, accuracy, and efficiency: The promises and practices of digitization in pathology

Digitization is often presented in policy discourse as a panacea to a multitude of contemporary problems, not least in healthcare. How can policy promises relating to digitization be assessed and potentially countered in particular local contexts? Based on a study in Denmark, we suggest scrutinizing the politics of digitization by comparing policy promises about the future with practitioners' experience in the present. While Denmark is one of the most digitalized countries in the world, digitization of pathology has only recently been given full policy attention. As pathology departments are faced with an increased demand for pathology analysis and a shortage of pathologists, Danish policymakers have put forward digitization as a way to address these challenges. Who is it that wants to digitize pathology, why, and how does digitization unfold in routine work practices? Using online search and document analysis, we identify actors and analyze the policy promises describing expectations associated with digitization. We then use interviews and observations to juxtapose these expectations with observations of everyday pathology practices as experienced by pathologists. We show that policymakers expect digitization to improve speed, patient safety, and diagnostic accuracy, as well as efficiency. In everyday practice, however, digitization does not deliver on these expectations. Fulfillment of policy expectations instead hinges on the types of artificial intelligence (AI) applications that are still to be developed and implemented. Some pathologists remark that AI might work in the easy cases, but this would leave them with only the difficult cases, which they consider too burdensome. Our particular mode of juxtaposing policy and practice throws new light on the political work done by policy promises and helps to explain why the discipline of pathology does not seem to easily lend itself to the digital embrace.

Impact on Survival of Early Versus Late Initiation of Adjuvant Chemotherapy After Pancreatic Adenocarcinoma Surgery: A Target Trial Emulation

BACKGROUND

We examined the impact of early (0-4 weeks after discharge) versus late (> 4-8 weeks after discharge) initiation of adjuvant chemotherapy on pancreatic adenocarcinoma survival.

METHODS

We used Danish population-based healthcare registries to emulate a hypothetical target trial using the clone-censor-weight approach. All eligible patients were cloned with one clone assigned to 'early initiation' and one clone assigned to 'late initiation'. Clones were censored when the assigned treatment was no longer compatible with the actual treatment. Informative censoring was addressed using inverse probability of censoring weighting.

RESULTS

We included 1491 patients in a hypothetical target trial, of whom 32.3% initiated chemotherapy within 0-4 weeks and 38.3% between > 4 and 8 weeks after discharge for pancreatic adenocarcinoma surgery; 206 (13.8%) initiated chemotherapy after > 8 weeks, and 232 (15.6%) did not initiate chemotherapy. Median overall survival was 30.4 and 29.9 months in late and early initiators, respectively. The absolute differences in OS, comparing late with early initiators, were 3.2% (95% confidence interval [CI] - 1.5%, 7.9%), - 0.7% (95% CI - 7.2%, 5.8%), and 3.2% (95% CI - 2.8%, 9.3%) at 1, 3, and 5 years, respectively. Late initiators had a higher increase in albumin levels as well as higher pretreatment albumin values.

CONCLUSIONS

Postponement of adjuvant chemotherapy up to 8 weeks after discharge from pancreatic adenocarcinoma surgery is safe and may allow more patients to receive adjuvant therapy due to better recovery.

There is a long way from current clinical practice in Denmark compared to recent published English guideline on management of children with eosinophilic oesophagitis

BACKGROUND

A low incidence of eosinophilic esophagitis (EoE) in children in the North Denmark Region (NDR) were measured in 2007-2017. Few of the children diagnosed before 2017 were treated to remission suggesting a lack of awareness. While there currently are no guidelines for treating EoE in Denmark, a new English guideline was published in 2022 renewing focus on the disease.

OBJECTIVE

The aim of this study was to measure the difference of current Danish clinical practice for treatment and follow-up of EoE children in the NDR with the new English guideline from the British Society of Gastroenterology (BSG) and the British Society of Pediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN).

METHODS

This retrospective, register-based DanEoE cohort study included 31 children diagnosed with EoE between 2007 and 2021 in NDR. Medical records were reviewed and information about treatment and follow-up were collected.

RESULTS

In 32% of the children with EoE in the NDR, first-line treatment corresponded with the new English guideline. One in 6 children were never started on any treatment even though treatment always is recommended. Histologic evaluation within 12 weeks as recommended was performed in 13% of the children.

CONCLUSIONS

In Denmark focus on improving EoE treatment and follow-up for children is needed, as there is a significant difference between current clinical practice and the recommendations in the new English guideline.

Effect of adjuvant chemotherapy after pancreatectomy in patients with node-negative pancreatic cancer: target trial emulation

BACKGROUND

The effect of adjuvant therapy in node-negative pancreatic cancer is uncertain. The aim of this study was to estimate the effect of adjuvant chemotherapy on survival after surgery for pancreatic cancer in patients with node-negative (pN0) and node-positive (pN+) disease using target trial emulation.

METHODS

This was an observational cohort study emulating a hypothetical RCT by the clone-censor-weight approach using population-based Danish healthcare registries. The study included Danish patients undergoing curative-intent surgery for pancreatic cancer during 2008-2021, who were discharged alive no more than 4 weeks after surgery. At the time of discharge after surgery, the data for each patient were duplicated; one copy was assigned to the adjuvant chemotherapy strategy and the other to the no adjuvant chemotherapy strategy of the hypothetical trial. Copies were censored when the assigned treatment was no longer compatible with the observed treatment. To account for informative censoring, uncensored patients were weighted according to measured confounders. The primary outcomes were absolute difference in 2-year survival and median overall survival, comparing adjuvant with no adjuvant chemotherapy.

RESULTS

Some 424 patients with pN0 and 953 with pN+ disease were included. Of these, 62.0 and 74.6% respectively initiated adjuvant chemotherapy within the 8-week grace period. Among patients with pN0 tumours, the difference in 2-year survival between those with and without adjuvant therapy was -2.2 (95% c.i. -11.8 to 7.4)%. In those with pN+ disease, the difference in 2-year survival was 9.9 (1.6 to 18.1)%. Median overall survival was 24.9 (i.q.r. 12.8-49.4) and 15.0 (8.0-34.0) months for patients having adjuvant and no adjuvant therapy respectively.

CONCLUSION

In a target trial emulation using observational data, adjuvant chemotherapy did not improve survival after surgery for node-negative pancreatic cancer.

Prognostic Factors for Relapse in Patients With Clinical Stage I Testicular Seminoma: A Nationwide, Population-Based Cohort Study

PURPOSE

Approximately 20% of patients with clinical stage I seminoma relapse. Tumor size and rete testis invasion have been identified as risk factors for relapse. However, the level of evidence supporting the use of these risk factors in clinical decision making is low. Previous studies have been hampered by selection bias and variable pathology reporting that limit interpretation and generalization of results. We assessed prognostic factors for relapse in an unselected nationwide population-based setting with centralized pathology review.

METHODS

Patients with clinical stage I seminoma diagnosed from January 2013 to December 2018 were identified in the prospective Danish Testicular Cancer database. By linkage to the Danish National Pathology Registry, histologic slides from the orchiectomy specimens were retrieved and reviewed blinded to the clinical outcome. Clinical data were obtained from medical records with follow-up until July 2022. The association between prespecified potential clinical and histopathologic prognostic factors and relapse was assessed by the use of Cox regression analysis.

RESULTS

Of 924 patients included, 148 (16%) patients relapsed during a median follow-up of 6.3 years. Invasion of the testicular hilum (rete testis and hilar soft tissue), lymphovascular invasion, and elevated preorchiectomy levels of β-human chorionic gonadotropin and lactate dehydrogenase were independent predictors of relapse. The estimated 5-year risk of relapse ranged from 6% in patients with no risk factors to 62% in patients with all four risk factors with tumor extension into the hilar soft tissue of the testicular hilum. After internal model validation, the prognostic model had an overall concordance statistic of 0.70.

CONCLUSION

The provided prognostic factors could replace current risk factors in guidelines and be used in future studies investigating risk-adapted follow-up and treatment strategies.

Beta-blocker use and survival after pancreatic cancer surgery: A nationwide population-based cohort study

PURPOSE

We examined the association between use of beta-blockers and survival in pancreatic cancer patients after curative-intent surgery.

METHODS

Using Danish healthcare registries, we conducted a population-based cohort study of all patients undergoing curative-intent surgery for pancreatic cancer in Denmark 1997-2021. We defined beta-blocker use according to exposure before surgery as current (≤90 days), recent (91-365 days), or former (366-730 days) use, requiring at least one filled prescription. Patients were followed from the date of surgery for up to 5 years. We used Cox regression to compute hazard ratios (HRs) of deaths with 95% confidence intervals (CIs), adjusting for age, sex, year of diagnosis, cardiovascular disease, diabetes, liver disease, alcohol, and smoking. We also conducted an active comparator analysis, where we used angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers as comparators instead of nonusers.

RESULTS

We included 2592 patients, of which 16.7% were beta-blocker users. Median survival for the entire population was 24.4 months. Beta-blocker use was associated with increased mortality (adjusted HR: 1.18; 95% CI: 1.04-1.34). This was evident in current (adjusted HR: 1.19; 95% CI: 1.02-1.38) and recent (adjusted HR: 1.29; 95% CI: 1.04-1.59) but not former (adjusted HR: 0.91; 95% CI: 0.64-1.43) users. In the active comparator analysis, the association between beta-blocker exposure and mortality attenuated slightly (adjusted HR: 1.12; 95% CI: 0.93-1.35).

CONCLUSIONS

We observed an association between beta-blocker use and increased mortality in patients operated for pancreatic cancer. Findings are likely explained by confounding by indication.

Atypical fibroxanthoma and pleomorphic dermal sarcoma: Local recurrence and metastasis in a nationwide population-based cohort of 1118 patients

BACKGROUND

The prognosis of patients with atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) remains uncertain and no standardized follow-up programs have been established.

OBJECTIVE

To recommend a standardized follow-up program of patients with AFX and PDS based on nationwide long-term estimates of local recurrence and metastasis.

METHODS

All patients with AFX and PDS in Denmark between 2002 and 2022 were included. Danish National Registries were used to estimate the risks of local recurrence and metastasis for AFX and PDS.

RESULTS

The 5-year risk of local recurrence was 10% for AFX and 17% for PDS. The 5-year risk of metastasis was 0.8% for AFX and 16% for PDS. PDS metastasized within 3 years in >90% of the patients with the lungs as the primary metastasis site (50%). Invasion beyond the subcutis, perineural/intravascular infiltration, and increasing age significantly increased the risk of PDS relapse.

LIMITATIONS

Risk of misclassification and lack of detailed surgical information.

CONCLUSION

The follow-up of patients with AFX can be limited to clinical visits for 4 years. Patients with PDS should be followed with clinical visits and PET/CT twice a year for the first 3 years and once a year for a minimum of 1 year.

Design and methodology of the PRIMETIME 1 cohort study: PRecIsion MEdicine based on kidney TIssue Molecular interrogation in diabetic nEphropathy

Background

Clinical features of diabetic kidney disease alone cannot differentiate between the histopathology that defines diabetic nephropathy (DN) and non-diabetic nephropathy (NDN). A kidney biopsy is necessary to make the definitive diagnosis of DN. However, there is no consensus on when to perform a kidney biopsy in individuals with diabetes and kidney disease. Furthermore, the implications of NDN versus DN for management, morbidity and kidney prognosis are unclear. To address the gap in knowledge, we aimed to create a national retrospective cohort of people with diabetes and a performed kidney biopsy.

Methods

Adults diagnosed with diabetes in Denmark between 1996 and 2020 who had a kidney biopsy performed were included. The cohort was established by linking a nationwide diabetes registry with the Danish Pathology Registry. Data from 11 national registries and databases were compiled. The type of kidney disease was classified using a three-step analysis of Systematized Nomenclature of Medicine codes reported in relation to the histopathological examinations of kidney tissue. The final cohort and classification of kidney disease was as follows: out of 485 989 individuals with diabetes 2586 were included, 2259 of whom had type 2 diabetes. We were able to classify 599 (26.5%) with DN, 703 (31.1%) with NDN and 165 (7.3%) with mixed disease in individuals with type 2 diabetes. In individuals with type 1 diabetes, 132 (40.4%) had DN, 73 (22.3%) NDN and 39 (11.9%) mixed disease. The remaining could not be classified or had normal histology. The overall median (Q1-Q3) follow-up time was 3.8 (1.6-7.2) years.

Conclusions

This cohort is a novel platform based on high-quality registry data for important longitudinal studies of the impact of kidney disease diagnosis on prognosis. With regular updates of data from the Danish registries, the presented follow-up will increase over time and is only limited by emigration or death.

Preoperative intravenous iron treatment - a cohort study on colorectal cancer recurrence

BACKGROUND

Intravenous (i.v.) iron treatment has been speculated to increase the malignant potential of colorectal malignancies but also to enhance the immune systems potential to fight the invasive tumor. Clinical data however is very limited. We investigate if preoperative i.v. iron treatment is associated with colorectal cancer (CRC) recurrence.

METHODS

Retrospective cohort study on surgical CRC patients with iron deficiency anemia (1st March 2013 - 31st December 2019). Patients were grouped based on whether they had received preoperative treatment with i.v. iron. Local data was combined with data from the National Danish Health registries to identify recurrences, death, and emigration. Survival analysis, including Kaplan-Meyer curves and multivariate competing risk analysis adjusting for sex, age, ASA-group, tumor stage, surgical radicality, and miss match repair status was performed.

RESULTS

Of 1228 patients, 125 were available for analysis. 89 patients had received preoperative i.v. iron and 36 had not. The two groups were comparable on baseline and surgical characteristics. Median follow-up times were 4.74 in iron treated patients and 5 years in patients not receiving iron treatment. Five-year rate of non-recurrence was 85 % (0.74-0.91) in the i.v. iron treated group vs. 82 % (0.64-0.91) in the control group, non-significant difference. Multivariate survival analysis did not find iron treatment to be associated with recurrence rates (Hazard Ratio 0.88 (95 % ci; 0.31-2.51).

CONCLUSION

No association between preoperative i.v. iron treatment and the five-year cancer recurrence rate in iron deficient anemic CRC patients was found.

Impact of prior cancer diagnosis on pancreatic cancer outcomes: A Danish Nationwide, population-based Cohort study

BACKGROUND

The overall survival of pancreatic cancer (PC) remains low, underlining the need of further research to improve PC directed therapy. Some patients with PC may have experienced a prior cancer, refraining them from inclusion in clinical trials, despite not knowing the precise effect of a prior cancer on disease course of PC.

OBJECTIVE

To examine the influence of prior cancer on the disease course in patients with PC.

METHODS

We conducted a cohort study including Danish patients diagnosed with PC between 2004 and 2020 crosslinking data from the Danish Cancer Registry, the Danish National Patient Registry among several other databases. Using the Kaplan-Meier estimator, we calculated the overall and American Joint Committee on Cancer (AJCC) disease stage stratified survival, comparing patients with and without prior cancer. Furthermore, using inverse probability of treatment weighting (IPTW), we presented a covariate-adjusted model of the average treatment effect in the treated (ATT) of prior cancer on the overall PC survival and stratified for AJCC disease stage.

RESULTS

We included 11,147 patients diagnosed with PC, of which 906 (8.1%) had a prior cancer. Comparing patients with and without prior cancer, the IPTW-adjusted survival, indicated a slightly better survival (ATT: 1.5 months; 95% CI: 0.7; 2.2 months). After stratifying by PC tumor stage, the difference was restricted to patients with stage IV PC disease (ATT: 1.1 months; 95% CI: 0.5; 1.7 months). Patients with prior cancer were slightly less prone to present with stage IV PC disease and were more likely to not receive active treatment compared with patients without prior cancer.

CONCLUSION

Prior cancer was associated with a slightly better survival in patients with PC, but only in patients with stage IV PC disease. This is likely explained by lead time bias.

Treatment patterns, survival, and healthcare utilisation and costs in patients with locally advanced and metastatic bladder cancer in Denmark 2015-2020

BACKGROUND

Treatment patterns in locally advanced and metastatic urothelial bladder cancer (La/mUBC) is changing, but little is known about current treatment patterns, survival, and costs of these patients. Our aim was to describe treatment patterns, survival, and healthcare utilisation/costs in Danish La/mUBC patients in a routine clinical care setting.

METHODS

Registry-based nationwide cohort study including all bladder cancer patients aged 18 years or older with a La/mUBC tumour in the pathology register and a concomitant bladder cancer diagnosis in the Danish National Patient Registry in the period 2015-2020. We categorised the patients according to (1) La/mUBC at time of first bladder cancer diagnosis (de novo La/mUBC) and (2) non-invasive or localised muscle-invasive bladder cancer at time of diagnosis which had progressed to La/mUBC. All patients were included at date of pathology-confirmed La/mUBC. Follow-up ended 30 September 2022.

RESULTS

We identified 1278 patients (69% men) with La/mUBC and no other previous cancer. Of these, 212 (17%) had de novo La/mUBC, while 1066 (83%) had progressed to La/mUBC. Median age was 72 years. Patients were followed for a median of 13.0 months (interquartile range 4.7;32.0). During follow-up, 651 (51%) patients started first-line treatment, of these, 285 progressed to second-line treatment, and 112 also started third-line treatment. Median survival was 13.0 months from La/mUBC diagnosis, 12.1 months from start of first-line treatment, 9.8 months from start of second-line treatment, and 8.6 months from start of third-line treatment. The mean number of days admitted to hospital was 3.47, 3.97, and 4.07 per month following initiation of first-line, second-line, and third-line treatment, respectively.

CONCLUSION

Patients with La/mUBC have a poor prognosis, and in routine clinical care only around half of the patients received systemic anti-cancer treatment suggesting an unmet need for novel treatments. The overall costs only increased slightly from first to third-line treatment.

Prediction of disease recurrence or residual disease after primary endoscopic resection of pT1 colorectal cancer-results from a large nationwide Danish study

PURPOSE

Risk assessment of disease recurrence in pT1 colorectal cancer is crucial in order to select the appropriate treatment strategy. The study aimed to develop a prediction model, based on histopathological data, for the probability of disease recurrence and residual disease in patients with pT1 colorectal cancer.

METHODS

The model dataset consisted of 558 patients with pT1 CRC who had undergone endoscopic resection only (n = 339) or endoscopic resection followed by subsequent bowel resection (n = 219). Tissue blocks and slides were retrieved from Pathology Departments from all regions in Denmark. All original slides were evaluated by one experienced gastrointestinal pathologist (TPK). New sections were cut and stained for haematoxylin and eosin (HE) and immunohistochemical markers. Missing values were multiple imputed. A logistic regression model with backward elimination was used to construct the prediction model.

RESULTS

The final prediction model for disease recurrence demonstrated good performance with AUC of 0.75 [95% CI 0.72-0.78], HL chi-squared test of 0.59 and scaled Brier score of 10%. The final prediction model for residual disease demonstrated medium performance with an AUC of 0.68 [0.63-0.72].

CONCLUSION

We developed a prediction model for the probability of disease recurrence in pT1 CRC with good performance and calibration based on histopathological data. Together with lymphatic and venous invasion, an involved resection margin (0 mm) as opposed to a margin of ≤ 1 mm was an independent risk factor for both disease recurrence and residual disease.

Impact of an in-consult patient decision aid on treatment choices and outcomes of management for patients with an endoscopically resected malignant colorectal polyp: a study protocol for a non-randomised clinical phase II study

INTRODUCTION

Management of an endoscopically resected malignant colorectal polyps can be challenging due to the risk of residual tumour and lymphatic spread. International studies have shown, that of those choosing surgical management instead of surveillance strategy, there are between 54% and 82% of bowel resections without evidence of residual tumour or lymphatic spread. As surgical management entails risks of complications and surveillance strategy entails risks of residual tumour or recurrence, a clinical dilemma arises when choosing a management strategy. Shared decision-making is a concept that can be used in preference-sensitive decision-making to facilitate patient involvement and empowerment to facilitate active patient participation in the decision-making process.

METHODS AND ANALYSIS

This study protocol describes our clinical multi-institutional, non-randomised, interventional phase II study at Danish surgical departments planned to commence in the second quarter of 2024. The aim of this study is to examine whether shared decision-making and using a patient decision aid in consultations affect patients' choice of management, comparing with retrospective data. The secondary aim is to investigate patients' experiences, perceived involvement, satisfaction, decision conflict and other outcomes using questionnaire feedback directly from the patients.

ETHICS AND DISSEMINATION

There are no conflicts of interest for principal or local investigators in any of the study sites. All results will be published at Danish and international meetings, and in English language scientific peer-reviewed journals. Our study underwent evaluation by the Regional Committees on Health Research Ethics for Southern Denmark (file number 20232000-47), concluding that formal approval was not required for this kind of research.

TRIAL REGISTRATION NUMBER

NCT05776381.