End-of-Life Care in the Last Three Months before Death in Older Patients with Cancer in Belgium: A Large Retrospective Cohort Study Using Data Linkage.

This study aims to describe end-of-life (EOL) care in older patients with cancer and investigate the association between geriatric assessment (GA) results and specialized palliative care (SPC) use. Older patients with a new cancer diagnosis (2009-2015) originally included in a previous multicentric study were selected if they died before the end of follow-up (2019). At the time of cancer diagnosis, patients underwent geriatric screening with Geriatric 8 (G8) followed by GA in case of a G8 score ≤14/17. These data were linked to the cancer registry and healthcare reimbursement data for follow-up. EOL care was assessed in the last three months before death, and associations were analyzed using logistic regression. A total of 3546 deceased older patients with cancer with a median age of 79 years at diagnosis were included. Breast, colon, and lung cancer were the most common diagnoses. In the last three months of life, 76.3% were hospitalized, 49.1% had an emergency department visit, and 43.5% received SPC. In total, 55.0% died in the hospital (38.5% in a non-palliative care unit and 16.4% in a palliative care unit). In multivariable analyses, functional and cognitive impairment at cancer diagnosis was associated with less SPC. Further research on optimizing EOL healthcare utilization and broadening access to SPC is needed.

Machine Learning Algorithm to Estimate Distant Breast Cancer Recurrence at the Population Level with Administrative Data.

Purpose: High-quality population-based cancer recurrence data are scarcely available, mainly due to complexity and cost of registration. For the first time in Belgium, we developed a tool to estimate distant recurrence after a breast cancer diagnosis at the population level, based on real-world cancer registration and administrative data. Methods: Data on distant cancer recurrence (including progression) from patients diagnosed with breast cancer between 2009-2014 were collected from medical files at 9 Belgian centers to train, test and externally validate an algorithm (i.e., gold standard). Distant recurrence was defined as the occurrence of distant metastases between 120 days and within 10 years after the primary diagnosis, with follow-up until December 31, 2018. Data from the gold standard were linked to population-based data from the Belgian Cancer Registry (BCR) and administrative data sources. Potential features to detect recurrences in administrative data were defined based on expert opinion from breast oncologists, and subsequently selected using bootstrap aggregation. Based on the selected features, classification and regression tree (CART) analysis was performed to construct an algorithm for classifying patients as having a distant recurrence or not. Results: A total of 2507 patients were included of whom 216 had a distant recurrence in the clinical data set. The performance of the algorithm showed sensitivity of 79.5% (95% CI 68.8-87.8%), positive predictive value (PPV) of 79.5% (95% CI 68.8-87.8%), and accuracy of 96.7% (95% CI 95.4-97.7%). The external validation resulted in a sensitivity of 84.1% (95% CI 74.4-91.3%), PPV of 84.1% (95% CI 74.4-91.3%), and an accuracy of 96.8% (95% CI 95.4-97.9%). Conclusion: Our algorithm detected distant breast cancer recurrences with an overall good accuracy of 96.8% for patients with breast cancer, as observed in the first multi-centric external validation exercise.

The Upgrade Risk of B3 Lesions to (Pre)Invasive Breast Cancer After Diagnosis on Core Needle or Vacuum Assisted Biopsy. A Belgian National Cohort Study.

INTRODUCTION: Flat epithelial atypia (FEA), lobular neoplasia (LN), papillary lesions (PL), radial scar (RS) and atypical ductal hyperplasia (ADH) are lesions of uncertain malignant potential and classified as B3 lesions by the European guidelines for quality assurance in breast cancer screening and diagnosis. Current management is usually wide local excision (WE), surveillance may be sufficient for some. We investigated the upgrade rate of B3 lesions to breast malignancy in a subsequent resection specimen after diagnosis on core needle-or vacuum assisted biopsy (CNB-VAB) in a national population-based series. METHODS: Using data from the Belgian Cancer Registry (BCR) between January 1, 2013 and December 31, 2016, inclusion criteria were new diagnosis of a B3 lesion on CNB or VAB with subsequent histological assessment on a wider excision specimen. Histological agreement between first- and follow-up investigation was analyzed to determine the upgrade risk to ductal adenocarcinoma in situ (DCIS) or invasive breast cancer (IC) according to the type of B3 lesion. RESULTS: Of 1855 diagnosed B3 lesions, 812 were included in this study: 551 after CNB-261 after VAB. After diagnosis on CNB and VAB, we found 19.0% and 14.9% upgrade to malignancy respectively. Upgrade risks after CNB and VAB were: FEA 39.5% and 17.6%; LN 40.5% and 4.3%; PL 10.4% and 12.5%; RS 25.7%and 0.0%; ADH 29.5% and 20.0%. CONCLUSION: Based on the observed upgrade rate we propose three recommendations: first, resection of ADH, and FEA with WE; second, resection of RS and classical LN with therapeutic VAB and further surveillance when radio-pathological correlation is concordant; third, surveillance of PL.

Linking clinical and population-based data in older patients with cancer in Belgium: Feasibility and clinical outcomes.

INTRODUCTION: Geriatric screening and geriatric assessment (GS/GA) have proven their benefits in the care for older patients with cancer. However, less is known about the predictive value of GS/GA for outcomes. To research this, clinical data on GS/GA can be enriched with population-based data. In this article we describe the methods and feasibility of data linkage, and first clinical outcomes (GS/GA results and overall survival). MATERIALS AND METHODS: A large cohort study consisting of patients aged ≥70 years with a new cancer diagnosis was established using linked data from clinical and population-based databases. Clinical data were derived from a previous prospective study where older patients with cancer were screened with G8, followed by GA in case of an abnormal result (GS/GA study; 2009-2015). These data were linked to cancer registration data from the Belgian Cancer Registry (BCR), reimbursement data of the health insurance companies (InterMutualistic Agency, IMA), and hospital discharge data (Technical Cell, TCT). Cox regression analyses were conducted to evaluate the prognostic value of the G8 geriatric screening tool. RESULTS: Of the 8067 eligible patients with a new cancer diagnosis, linkage of data from the GS/GA study and data from the BCR was successful for 93.7%, resulting in a cohort of 7556 patients available for the current analysis. Further linkage with the IMA and TCT database resulted in a cohort of 7314 patients (96.8%). Based on G8 geriatric screening, 67.9% of the patients had a geriatric risk profile. Malnutrition and functional dependence were the most common GA-identified risk factors. An abnormal baseline G8 score (≤14/17) was associated with lower overall survival (adjusted HR [aHR] = 1.62 [1.50-1.75], p < 0.001). DISCUSSION: Linking clinical and population-based databases for older patients with cancer has shown to be feasible. The GS/GA results at cancer diagnosis demonstrate the vulnerability of this population and the G8 score showed prognostic value for overall survival. The established cohort of almost 8000 patients with long-term follow-up will serve as a basis in the future for detailed analyses on long-term outcomes beyond survival.

The Impact of a Six-Year Existing Screening Programme Using the Faecal Immunochemical Test in Flanders (Belgium) on Colorectal Cancer Incidence, Mortality and Survival: A Population-Based Study.

The faecal immunochemical test (FIT) has been increasingly used for organised colorectal cancer (CRC) screening. We assessed the impact of a six-year existing FIT screening programme in Flanders (Belgium) on CRC incidence, mortality and survival. The Flemish CRC screening programme started in 2013, targeting individuals aged 50-74 years. Joinpoint regression was used to investigate trends of age-standardised CRC incidence and mortality among individuals aged 50-79 years (2004-2019). Their 5-year relative survival was calculated using the Ederer II method. We found that FIT screening significantly reduced CRC incidence, especially that of advanced-stage CRCs (69.8/100,000 in 2012 vs. 51.1/100,000 in 2019), with a greater impact in men. Mortality started to decline in men two years after organised screening implementation (annual reduction of 9.3% after 2015 vs. 2.2% before 2015). The 5-year relative survival was significantly higher in screen-detected (93.8%) and lower in FIT non-participant CRCs (61.9%) vs. FIT interval cancers and CRCs in never-invited cases (67.6% and 66.7%, respectively). Organised FIT screening in Flanders clearly reduced CRC incidence (especially advanced-stage) and mortality (in men, but not yet in women). Survival is significantly better in screen-detected cases vs. CRCs in unscreened people. Our findings support the implementation of FIT organised screening and the continued effort to increase uptake.

The effect of the Flemish breast cancer screening program on breast cancer-specific mortality: A case-referent study.

BACKGROUND: Breast cancer screening programs were introduced in many countries worldwide following randomized controlled trials in the 1980s showing a reduction in breast cancer-specific mortality. However, their effectiveness remains debated and estimates vary. A breast cancer screening program was introduced in 2001 in Flanders, Belgium where high levels of opportunistic screening practices are observed. The effectiveness of this program was estimated by measuring its effect on breast cancer-specific mortality. METHODS: We performed a case-referent study to investigate the effect of participation in the Flemish population-based mammography screening program (PMSP) on breast cancer-specific mortality from 2005 to 2017. A multiple logistic regression model assessed the association between breast cancer-specific death and screening program participation status in the four years prior to (pseudo)diagnosis (yes/no), with adjustment for potential confounders (individual socio-economic position and calendar year of diagnosis) and stratified for age. In addition, we performed different sensitivity analyses. RESULTS: We identified 1571 cases and randomly selected 6284 referents. After adjustment, women who participated in PMSP had a 51 % lower risk of breast cancer-specific mortality compared to those who did not (adjusted odds ratio [aOR] =0.49, 95 % CI: 0.44-0.55). Sensitivity analyses did not markedly change the estimated associations. Correction for self-selection bias reduced the effect size, but the estimate remained significant. CONCLUSION: Our results indicate that in a context of high opportunistic screening rates, participation in breast cancer screening program substantially reduces breast cancer-specific mortality. For policy, these results should be balanced against the potential harms of screening, including overdiagnosis and overtreatment.

Effectiveness of Organized Mammography Screening for Different Breast Cancer Molecular Subtypes.

BACKGROUND: Screening program effectiveness is generally evaluated for breast cancer (BC) as one disease and without considering the regularity of participation, while this might have an impact on detection rate. OBJECTIVES: To evaluate the short-term effectiveness of a mammography screening program for the major molecular subtypes of invasive BC. METHODS: All women who participated in the screening program and were diagnosed with screen-detected or interval BC in Flanders were included in the study (2008-2018). Molecular subtypes considered were luminal and luminal-HER2-positive, human epidermal growth factor receptor 2-positive, and triple-negative BC (TNBC). The relationship between the BC stage at diagnosis (early (I-II) versus advanced (III-IV)) and the method of detection (screen-detected or interval) and the relationship between the method of detection and participation regularity (regular versus irregular) were evaluated by multi-variable logistic regression models. All models were performed for each molecular subtype and adjusted for age. RESULTS: Among the 12,318 included women, BC of luminal and luminal-HER2-positive subtypes accounted for 70.9% and 11.3%, respectively. Screen-detected BC was more likely to be diagnosed at early stages than interval BC with varied effect sizes for luminal, luminal-HER2-positive, and TNBC with OR:2.82 (95% CI: 2.45-3.25), OR:2.39 (95% CI: 1.77-3.24), and OR:2.29 (95% CI: 1.34-4.05), respectively. Regular participation was related to a higher likelihood of screening detection than irregular participation for luminal, luminal-HER2-positive, and TNBC with OR:1.21 (95% CI: 1.09-1.34), OR: 1.79 (95% CI: 1.38-2.33), and OR: 1.62 (95% CI: 1.10-2.41), respectively. CONCLUSIONS: Regular screening as compared to irregular screening is effective for all breast cancers except for the HER2 subtype.

Colorectal cancer incidence and survival inequalities among labour immigrants in Belgium during 2004-2013.

Colorectal cancer (CRC) is one of the leading causes of cancer-related morbidity and mortality. We aim to map out differences in CRC incidence and survival between first-generation traditional labour immigrants of Italian, Turkish and Moroccan descent and native Belgians; and assess the contribution of socioeconomic position (SEP) to these differences. Individually-linked data of the 2001 Belgian Census, the Crossroads Bank for Social Security and the Belgian Cancer Registry are used. Age-standardized incidence rates and incidence rate ratios are calculated by country of origin, with and without adjusting for SEP. For CRC patients, 5-year relative survival rates and the relative excess risk for dying within five years after diagnosis are calculated by migrant origin. Lower CRC incidence was observed among immigrants compared to native Belgians, in particular among non-Western immigrants, which could not be explained by SEP. Survival inequalities were less clear, yet, after adjusting for age and stage at diagnosis and educational attainment, we observed a survival advantage among Turkish and Italian immigrant men. Health gains can be made for the native population by adapting lifestyle. The later stage at diagnosis for immigrants is of concern. Barriers regarding screening as perceived by the vulnerable groups should be identified.

Overdiagnosis of invasive breast cancer in population-based breast cancer screening: A short- and long-term perspective.

BACKGROUND: Overdiagnosis of invasive breast cancer (BC) is a contentious issue. OBJECTIVE: The aim of this paper is to estimate the overdiagnosis rate of invasive BC in an organised BC screening program and to evaluate the impact of age and follow-up time. METHODS: The micro-simulation model SiMRiSc was calibrated and validated for BC screening in Flanders, where women are screened biennially from age 50 to 69. Overdiagnosis rate was defined as the number of invasive BC that would not have been diagnosed in the absence of screening per 100,000 screened women during the screening period plus follow-up time (which was set at 5 years and varied from 2 to 15 years). Overdiagnosis rate was calculated overall and stratified by age. RESULTS: The overall overdiagnosis rate for women screened biennially from 50 to 69 was 20.1 (95%CI: 16.9-23.2) per 100,000 women screened at 5-year follow-up from stopping screening. Overdiagnosis at 5-year follow-up time was 12.9 (95%CI: 4.6-21.1) and 74.2 (95%CI: 50.9-97.5) per 100,000 women screened for women who started screening at age 50 and 68, respectively. At 2- and 15-year follow-up time, overdiagnosis rate was 98.5 (95%CI: 75.8-121.3) and 13.4 (95%CI: 4.9-21.9), respectively, for women starting at age 50, and 297.0 (95%CI: 264.5-329.4) and 34.2 (95%CI: 17.5-50.8), respectively, for those starting at age 68. CONCLUSIONS: Sufficient follow-up time (≥10 years) after screening stops is key to obtaining unbiased estimates of overdiagnosis. Overdiagnosis of invasive BC is a larger problem in older compared to younger women.

Overall and stage-specific survival of patients with screen-detected colorectal cancer in European countries: A population-based study in 9 countries.

Background: An increasing proportion of colorectal cancers (CRCs) are detected through screening due to the availability of organised population-based programmes. We aimed to analyse survival probabilities of patients with screen-detected CRC in European countries. Methods: Data from CRC patients were obtained from 16 population-based cancer registries in nine European countries. We included patients with cancer diagnosed from the year organised CRC screening programmes were introduced until the most recent year with available data at the time of analysis, whose ages at diagnosis fell into the age groups targeted by screening. Patients were followed up with regards to vital status until 2016-2020 across the various countries. Overall and CRC-specific survival were analysed by mode of detection and stage at diagnosis for all countries combined and for each country separately using the Kaplan-Meier method. Findings: We included data from 228 134 patients, of whom 134 597 (aged 60-69 years at diagnosis targeted by screening in all countries) were considered in analyses for all countries combined. 22·3% (38 080/134 597) of patients had cancer detected through screening. Most screen-detected cancers were found at stages I-II (65·6% [12 772/19 469 included in stage-specific analyses]), while the majority of non-screen-detected cancers were found at stages III-IV (56·4% [31 882/56 543 included in stage-specific analyses]). Five-year overall and CRC-specific survival rates for patients with screen-detected cancer were 83·4% (95% CI 82·9-83·9) and 89·2% (88·8-89·7), respectively; for patients with non-screen-detected cancer, they were much lower (57·5% [57·2-57·8] and 65·7% [65·4-66·1], respectively). The favourable survival of patients with screen-detected cancer was also seen within each stage - five-year overall survival rates for patients with screen-detected stage I, II, III, and IV cancers were 92.4% (95% CI 91·6-93·1), 87·9% (86·6-89·1), 80·7% (79·3-82·0), and 32·3 (29·4-35·2), respectively. These patterns were also consistently seen for each individual country. Interpretation: Patients with cancer diagnosed at screening have a very favourable prognosis. In the rare case of detection of advanced stage cancer, survival probabilities are still much higher than those commonly reported for all patients regardless of mode of detection. Although these results cannot be taken to quantify screening effects, they provide useful and encouraging information for patients with screen-detected CRC and their physicians. Funding: This study was supported in part by grants from the German Federal Ministry of Education and Research and the German Cancer Aid.

Survival trends of patients with non-metastatic gastric adenocarcinoma in the US and European countries: the impact of decreasing resection rates.

BACKGROUND: We previously observed decreasing resection rates of non-metastatic gastric adenocarcinoma (GaC) in the US and some European countries. If and to what extent these trends affect the trends in overall survival (OS) of patients with non-metastatic GaC at the population level remain unclear. This large international population-based cohort study aimed to assess the impact of the previously observed decreasing resection rates on multivariable-adjusted trends in the long-term OS of patients with non-metastatic GaC. METHODS: Individual-level data of patients with non-metastatic GaC were obtained from the national cancer registries of the Netherlands, Belgium, Sweden, Norway, and Slovenia, and the US Surveillance, Epidemiology, and End Results database. We analyzed data for each country separately. Associations between year of diagnosis and OS were assessed using Cox proportional hazards regression model with adjustment for multiple prognostic variables, with and without including resection and chemotherapy as potential explanatory variables. RESULTS: A total of 66,398 non-metastatic GaC patients diagnosed in 2003-2016 were analyzed, with an accumulated follow-up of 172,357 person-years. Without adjustment for resection, OS was improved only slightly in the US [hazard ratio (HR)per year = 0.99; HR≥vs.<2010 = 0.96], and no improvement was observed in the investigated European countries, with OS even worsening in Sweden (HRper year = 1.03; HR≥vs.<2010 = 1.17). After adjusting for resection, the increasing OS trend became stronger in the US (HRper year = 0.98; HR≥vs.<2010 = 0.88), and the temporal trend became insignificant in Sweden. In Slovenia (HRper year = 0.99; HR≥vs.<2010 = 0.92) and Norway (HRper year = 0.97; HR≥vs.<2010 = 0.86), improved OS over time emerged after resection adjustment. Improved OS in patients undergoing resection was observed in the US, the Netherlands, and Norway. Adjustment for chemotherapy did not alter the observed associations. Stratified analyses by tumor location showed mostly similar results with the findings in all patients with non-metastatic GaCs regarding the associations between year of diagnosis and survival. CONCLUSIONS: OS of patients with non-metastatic GaC mostly did not improve in selected European countries and was even worsened in Sweden, while it was slightly increased in the US in the early 21st century. Progress in OS of patients with non-metastatic GaC seems to have been impeded to a large extent by decreasing rates of resection.

Proportion and stage distribution of screen-detected and non-screen-detected colorectal cancer in nine European countries: an international, population-based study.

BACKGROUND: The effects of recently implemented colorectal cancer screening programmes in Europe on colorectal cancer mortality will take several years to be fully known. We aimed to analyse the characteristics and parameters of screening programmes, proportions of colorectal cancers detected through screening, and stage distribution in screen-detected and non-screen-detected colorectal cancers to provide a timely assessment of the potential effects of screening programmes in several European countries. METHODS: We conducted this population-based study in nine European countries for which data on mode of detection were available (Belgium, Denmark, England, France, Italy, Ireland, the Netherlands, Slovenia, and Spain). Data from 16 population-based cancer registries were included. Patients were included if they were diagnosed with colorectal cancer from the year that organised colorectal cancer screening programmes were implemented in each country until the latest year with available data at the time of analysis, and if their age at diagnosis fell within the age groups targeted by the programmes. Data collected included sex, age at diagnosis, date of diagnosis, topography, morphology, clinical and pathological TNM information based on the edition in place at time of diagnosis, and mode of detection (ie, screen detected or non-screen detected). If stage information was not available, patients were not included in stage-specific analyses. The primary outcome was proportion and stage distribution of screen-detected versus non-screen detected colorectal cancers. FINDINGS: 228 667 colorectal cancer cases were included in the analyses. Proportions of screen-detected cancers varied widely across countries and regions. The highest proportions (40-60%) were found in Slovenia and the Basque Country in Spain, where FIT-based programmes were fully rolled out, and participation rates were higher than 50%. A similar proportion of screen-detected cancers was also found for the Netherlands in 2015, where participation was over 70%, even though the programme had not yet been fully rolled out to all age groups. In most other countries and regions, proportions of screen-detected cancers were below 30%. Compared with non-screen-detected cancers, screen-detected cancers were much more often found in the distal colon (range 34·5-51·1% screen detected vs 26·4-35·7% non-screen detected) and less often in the proximal colon (19·5-29·9% screen detected vs 24·9-32·8% non-screen detected) p≤0·02 for each country, more often at stage I (35·7-52·7% screen detected vs 13·2-24·9% non-screen detected), and less often at stage IV (5·8-12·5% screen detected vs 22·5-31·9% non-screen detected) p<0·0001 for each country. INTERPRETATION: The proportion of colorectal cancer cases detected by screening varied widely between countries. However, in all countries, screen-detected cancers had a more favourable stage distribution than cancers detected otherwise. There is still much need and scope for improving early detection of cancer across all segments of the colorectum, and particularly in the proximal colon and rectum. FUNDING: Deutsche Krebshilfe.

Quality indicators in neuro-oncology: Review of the literature and development of a new quality indicator set for glioma care through a two-round Delphi survey.

BACKGROUND: Quality Indicators (QIs) are important tools to assess the quality and variability of oncological care. However, their application in neuro-oncology is limited so far. The objective of this study was to develop a set of QIs for glioma, covering process and outcome indicators. METHODS: A systematic review was conducted to identify both QIs in the field of adult glioma care, and guidelines or recommendations that could be translated into QIs. Also reports from national and international healthcare agencies and scientific associations ("grey literature") were taken into account. After conversion of these recommendations into QIs, merging with existing QIs found in the literature and rationalization, a two-round Delphi survey was conducted to gain consensus on relevance for the proposed QIs. RESULTS: In total 240 recommendations and 30 QIs were retrieved from the literature. After conversion, merging and rationalization, 147 QIs were evaluated in the Delphi survey and eventually consensus was gained on 47 QIs in the following 7 domains: Diagnosis and Imaging, Surgery, Pathology, Radio/Chemotherapy, Recurrence, Supportive Treatments (Epilepsy, Thromboembolism, Steroid Use and Rehabilitation) and Survival. CONCLUSION: This study defined a set of 47 QIs for assessing quality of care in adult glioma patients, distributed amongst 7 crucial phases in the patient's care trajectory. These QIs are readily applicable for use in diverse health care systems, depending on the availability of population-based health care data enabling (inter)national benchmarking.

Combining data to perform population-based observational studies: know your sources. The case of thyroid cancer in Belgium.

BACKGROUND: Large scale observational studies are crucial to study thyroid cancer incidence and management, known to vary in time and place. Combining cancer registry data with other data sources enables execution of population-based studies, provided data sources are accurate. The objective was to compare thyroid tumour and treatment information between the available data sources in Belgium. METHODS: We performed a retrospective national population-based cohort study. All patients with thyroid cancer diagnosis in Belgium between 2009 and 2011 (N = 2659 patients) were retrieved from the Belgian Cancer Registry database, containing standard patient and tumour characteristics. Additionally, information was obtained from the following sources: a) detailed pathology reports b) the health insurance company database for reimbursed performed therapeutic acts (both available for N = 2400 patients) c) registration forms for performed and/or planned treatments at the time of the multidisciplinary team meeting (available for N = 1819 patients). More precisely, information was retrieved regarding characteristics of the tumour (histologic subtype, tumour size, lymph node status (source a)) and the treatment (thyroid surgery (a,b,c), lymph node dissection (a,b), postoperative administration of radioactive iodine (b,c)). RESULTS: High concordance in histological cancer subtype (> 90%), tumour size (96.2%) and lymph node involvement (89.2%) categories was found between the cancer registry database and the pathology reports. Tumour subcategories (such as microcarcinoma, tumor ≤1 cm diameter) were more specified in the pathology reports. The therapeutic act of thyroid surgery as mentioned in the pathology reports and health insurance company database was concordant in 92.7%, while reports from multidisciplinary team meetings showed 88.5% of concordance with pathology reports and 86.1% with health insurance data. With regard to postoperative radioiodine administration, reports from multidisciplinary teams and health insurance data were concordant in 76.8%. CONCLUSION: Combining registered and/or administrative data results in sufficiently accurate information to perform large scale observational studies on thyroid cancer in Belgium. However, thorough and continuous quality control and insight in strengths and limitations of each cancer data source is crucial.

Optimizing the colorectal cancer screening programme using faecal immunochemical test (FIT) in Flanders, Belgium from the "interval cancer" perspective.

BACKGROUND: Interval cancer (IC) is a critical issue in colorectal cancer (CRC) screening. We identified factors associated with ICs after faecal immunochemical test (FIT) screening and explored the impact of lowering FIT cut-off or shortening screening interval on FIT-ICs in Flanders. METHODS: FIT participants diagnosed with a CRC during 2013-2018 were included. Factors associated with FIT-ICs were identified using logistic regression. Distributions of FIT results among FIT-ICs were examined. RESULTS: In total, 10,122 screen-detected CRCs and 1534 FIT-ICs were included (FIT-IC proportion of 13%). FIT-ICs occurred more frequently in women (OR 1.58 [95% CI 1.41-1.76]) and ages 70-74 (OR 1.35 [1.14-1.59]). FIT-ICs were more often right-sided (OR 3.53 [2.98-4.20]), advanced stage (stage IV: OR 7.15 [5.76-8.88]), and high grade (poorly/undifferentiated: OR 2.57 [2.08-3.18]). The majority (83-92%) of FIT-ICs would still be missed if FIT cut-off was lowered from 15 to 10 µg Hb/g or screening interval was shortened from 2 to 1 year. CONCLUSIONS: FIT-ICs were more common in women, older age, right-sided location, advanced stage and high grade. In Flanders, lowering FIT cut-off (to 10 µg Hb/g) or shortening screening interval (to 1 year) would have a minimal impact on FIT-ICs.

Machine Learning-Based Extraction of Breast Cancer Receptor Status From Bilingual Free-Text Pathology Reports.

As part of its core business of gathering population-based information on new cancer diagnoses, the Belgian Cancer Registry receives free-text pathology reports, describing results of (pre-)malignant specimens. These reports are provided by 82 laboratories and written in 2 national languages, Dutch or French. For breast cancer, the reports characterize the status of estrogen receptor, progesterone receptor, and Erb-b2 receptor tyrosine kinase 2. These biomarkers are related with tumor growth and prognosis and are essential to define therapeutic management. The availability of population-scale information about their status in breast cancer patients can therefore be considered crucial to enrich real-world scientific studies and to guide public health policies regarding personalized medicine. The main objective of this study is to expand the data available at the Belgian Cancer Registry by automatically extracting the status of these biomarkers from the pathology reports. Various types of numeric features are computed from over 1,300 manually annotated reports linked to breast tumors diagnosed in 2014. A range of popular machine learning classifiers, such as support vector machines, random forests and logistic regressions, are trained on this data and compared using their F 1 scores on a separate validation set. On a held-out test set, the best performing classifiers achieve F 1 scores ranging from 0.89 to 0.92 for the four classification tasks. The extraction is thus reliable and allows to significantly increase the availability of this valuable information on breast cancer receptor status at a population level.

Population-Based Data Reveal Factors Associated with Organised and Non-Organised Colorectal Cancer Screening: An Important Step towards Improving Coverage.

We investigated factors associated with organised and non-organised colorectal cancer screening using faecal occult blood tests, based on data from 308 municipalities in Flanders (6.6 million residents, 57% of Belgium) during 2015-2017. Logistic regression with generalized estimating equations was used to assess the associations between municipal characteristics and organised and non-organised screening coverages. Factors associated negatively with both organised and non-organised screening: percentage of people aged 70-74 in the target population [OR (odds ratios) = 0.98, 95%CI (confidence interval): 0.97-0.99 and OR = 0.98, 95%CI: 0.96-0.999, respectively]; negatively with organised screening: average income [OR = 0.97, 95%CI: 0.96-0.98], percentage of people with a non-Belgian/Dutch nationality [OR = 0.962, 95%CI: 0.957-0.967]; positively with organised screening: percentages of men in the target population [OR = 1.13, 95%CI: 1.11-1.14], jobseekers [OR = 1.12, 95%CI: 1.09-1.15] and people with at least one general practitioner (GP) visit in the last year [OR = 1.04, 95%CI: 1.03-1.05]; positively with non-organised screening: number of patients per GP [OR = 1.021, 95%CI: 1.016-1.026], percentage of people with a global medical dossier handled by a preferred GP [OR = 1.025, 95%CI: 1.018-1.031]. This study helps to identify the hard-to-reach subpopulations in CRC screening, and highlights the important role of GPs in the process of promoting screening among non-participants and encouraging non-organised participants to switch to organised screening.

Excess Mortality in a Nationwide Cohort of Cancer Patients during the Initial Phase of the COVID-19 Pandemic in Belgium.

BACKGROUND: Most studies investigating the impact of coronavirus infectious disease-19 (COVID-19) on mortality among patients with cancer were performed in a hospital setting, and the evidence is thus based on a selected and frail subset of patients. This study evaluates the excess mortality during the first wave of COVID-19 in a nationwide, prevalent cancer cohort in Belgium. METHODS: Mortality was studied among almost 240,000 patients with cancer diagnosed between 2013 and 2018 and alive on January 1, 2020. The observed number of deaths in the months January to June 2020 was compared with the expected number of deaths applying the monthly mortality rates observed in the cancer cohort during the previous years. A comparison using the excess mortality rates from the general population was performed. RESULTS: An excess number of deaths of about 400 was observed in the month of April, coinciding with a peak of COVID-19 diagnoses in Belgium and corresponding to a 33% rise in mortality. A comparable number of excess deaths was estimated if the COVID-19 excess mortality rates from the general Belgian population were applied to the cancer cohort, stratified by age and sex. CONCLUSIONS: A considerable excess mortality in the Belgian cancer cohort was observed during the initial peak of COVID-19 in Belgium. The pattern of excess mortality was, however, not markedly different from that observed in the general population. IMPACT: These results suggest that the susceptibility of prevalent cancer patients to COVID-19-induced mortality during the first wave of the pandemic was comparable with the general population.

Largely varying patterns and trends of primary cancer-directed resection for gastric carcinoma with synchronous distant metastasis in Europe and the US: a population-based study calling for further standardization of care.

AIMS: The role of resection remains debated in cases of metastatic gastric carcinoma (mGC). Some mGCs are technically resectable. At the population level, the real-world application of resection for mGC remains largely unclear in most Western countries. This large, population-based international investigation aimed to reveal the resection patterns and trends for mGC and the treatment-associated factors in Europe and the US. METHODS: Data on cases with microscopically-confirmed primary invasive stomach carcinoma with distant metastasis were obtained from the nationwide cancer registries of the Netherlands, Belgium, Norway, Sweden, Estonia, and Slovenia and the US Surveillance, Epidemiology, and End Results-18 database. We calculated age-standardized rates of primary cancer-directed resection and assessed resection trends using linear regression. We investigated associations of treatment with patient and cancer factors using multivariable-adjusted log-binomial regression. RESULTS: Among 133,321 patients with gastric cancer, overall, 40,215 cases with mGC diagnosed between 2003-2017 were investigated. Age-standardized resection rates significantly declined over time in the US, Belgium, Sweden, and Norway (by 5-14%). Resection rates greatly differed from 5% to 16% in 2013-2014. Cases with older ages, cardia tumors, or tumors involving adjacent structures were significantly less often operated across most countries. Sex was not significantly associated with resection. Across countries the association patterns and strengths differed largely. With multivariable adjustment, resection rates decreased significantly in all countries except Slovenia and Estonia (prevalence ratio per year = 0.90-0.98), and the decreasing trends were consistently observed in various stratifications by age and location. CONCLUSION: In Europe and the US, resection patterns and trends largely varied across countries for mGCs, which were mostly less often resected in the early 21st century. Various resection-associated factors were shown, with greatly varying association patterns and strengths. Our report could aid to identify discrepancies in clinical practice and highlight the great need for further clarifying the role of resection in mGCs to enhance standardization of care.