Functional Outcomes and Quality of Life in High-risk Prostate Cancer Patients Treated by Robot-assisted Radical Prostatectomy with or Without Adjuvant Treatments.

BACKGROUND: Robot-assisted laparoscopic prostatectomy (RALP) is used frequently to treat prostate cancer; yet, prospective data on the quality of life and functional outcomes are lacking. OBJECTIVE: To assess the quality of life and functional outcomes after radical prostatectomy in different risk groups with or without adjuvant treatments. DESIGN, SETTING, AND PARTICIPANTS: The Be-RALP database is a prospective multicentre database that covers 9235 RALP cases from 2009 until 2016. Of these 9235 patients, 2336 high-risk prostate cancer patients were matched with low/intermediate-risk prostate cancer patients. INTERVENTION: Patients were treated with RALP only or followed by radiotherapy and/or hormone treatment. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We used a mixed-model analysis to longitudinally analyse quality of life, urinary function, and erectile function between risk groups with or without additional treatments. RESULTS AND LIMITATIONS: Risk group was not significant in predicting quality of life, erectile function, or urinary function after RALP. Postoperative treatment (hormone and/or radiotherapy treatment) was significant in predicting International Index of Erectile Function (IIEF-5), sexual activity, and sexual functioning. CONCLUSIONS: Risk group was not linked with clinically relevant declines in functional outcomes after RALP. The observed functional outcomes and quality of life are in favour of considering RALP for high-risk prostate cancer. Postoperative treatment resulted in lower erectile function measures without clinically relevant changes in quality of life and urinary functions. Hormone therapy seems to have the most prominent negative effects on these outcomes. PATIENT SUMMARY: This study investigated the quality of life, and urinary and erectile function in patients with aggressive and less aggressive prostate cancer after surgery only or in combination with hormones or radiation. We found that quality of life recovers completely, while erectile and urinary function recovers only partially after surgery. Aggressiveness of the disease had a minimal effect on the outcomes; yet, postoperative treatments lowered erectile function further.

Cancer incidence, stage shift and survival during the 2020 COVID-19 pandemic: A population-based study in Belgium.

The COVID-19 pandemic was associated with a profound decline in cancer diagnoses in 2020 in Belgium. Disruption in diagnostic and screening services and patient reluctance to visit health facilities led to fewer new cases and concerns that cancers may be diagnosed at more advanced stages and hence have poorer prognosis. Using data from mandatory cancer registration covering all of Belgium, we predicted cancer incidence, stage distribution and 1-year relative survival for 2020 using a Poisson count model over the preceding years, extrapolated to 2020 for 11 common cancer types. We compared these expected values to the observed values in 2020 to specifically quantify the impact of the COVID-19 pandemic, accounting for background trends. A significantly lower incidence was observed for cervical, prostate, head and neck, colorectal, bladder and breast cancer, with limited or no recovery of diagnoses in the second half of 2020 for these cancer types. Changes in stage distribution were observed for cervical, prostate, bladder and ovarian and fallopian tube tumours. Generally, changes in stage distribution mainly represented decline in early-stage than in late-stage tumours. One-year relative survival was lower than predicted for lung cancer and colorectal cancer. Stage shifts are hypothesised to result from alterations in access to diagnosis, potentially due to prioritisation of symptomatic patients, and patient reluctance to contact a physician. Since there were over 5000 fewer cancer diagnoses than expected by the end of 2020, it is critical to monitor incidence, stage distribution and survival for these cancers in the coming years.

Hospital Volume for Rectal Cancer Resection Plays a Pivotal Role in Improving Outcomes: A Population-based Analysis.

OBJECTIVE: Assessing the association between hospital surgical volume (SV) and outcomes after rectal cancer surgery (RCS), using national population-based data. SUMMARY BACKGROUND DATA: For RCS, the association of higher SV with improved short- and/or long-term outcomes remains controversial. METHODS: National cancer registry data and administrative data were used to select patients diagnosed with stage I-III rectal cancer in 2009-2018 and who underwent RCS. The average annual SV of RCS was categorised as low (<15; LV), medium (15-29; MV) or high (≥30; HV). The association between SV and 90-day and 1-year excess postoperative mortality (90DPM and 1YEPM) and 5-year observed survival (5YOS) was evaluated. RESULTS: From the 11,519 patients , RCS was performed in LV (4,088; 36%), MV (2,795; 24%) or HV (4,636; 40%) hospitals. Observed 90DPM was significantly better in HV (2.3% 95%CI[1.9,2.8]) than in LV (3.7% 95%CI[3.2,4.4]) and MV (3.5% 95%CI[2.9,4.3]) with adjusted OR 1.4, P<0.0001. Continuous regression analysis showed significantly higher 90DPM in annual SV <35 compared to ≥35 (OR 1.6 95%CI[1.21,2.11]; P=0.0009). Observed 1YEPM was significantly better in HV (2.9% 95%CI[2.2,3.6]) compared to LV (4.7% 95%CI [3.9,5.6]) with adjusted excess HR 1.31 95%CI[1.00,1.73] and P=0.05, and to MV (5.0% 95%CI[4.0,6.1]) with adjusted excess HR 1.45 95%CI[1.09,1.94] and P=0.01. The 5YOS was significantly better in HV (75.9% 95%CI[74.6,77.2]) than in LV (70.3% 95%CI[68.8,71.8]) and MV (71.5% 95%CI[69.7,73.2]) with adjusted HR 1.4 in both LV and MV versus HV, P≤0.003. CONCLUSIONS: This population-based study identified robustly superior outcomes at 90-days, 1-year and 5-years after RCS in hospitals with higher volumes.

Breast cancer incidence, stage distribution, and treatment shifts during the 2020 COVID-19 pandemic: a nationwide population-level study.

BACKGROUND: The first COVID-19 wave in 2020 necessitated temporary suspension of non-essential medical services including organized cancer screening programs in Belgium. This study assessed the impact of the pandemic on breast cancer (BC) incidence, stage at diagnosis, and management in Belgium in 2020. METHODS: All Belgian residents diagnosed with in situ or invasive BC in 2015-2020 in the nationwide, population-based cancer registry database were included. Incidence trends for 2015-2019 were extrapolated to predict incidence and stage distribution for 2020 and compared with the observed values. National healthcare reimbursement data were used to examine treatment strategies. Exact tumor diameter and nodal involvement, extracted from pathology reports, were analyzed for 2019 and 2020. RESULTS: 74,975 tumors were selected for analysis of incidence and clinical stage. Invasive BC incidence declined by -5.0% in 2020, with a drop during the first COVID-19 wave (Mar-Jun; -23%) followed by a rebound (Jul-Dec; +7%). Predicted and observed incidence (in situ + invasive) was not different in patients < 50 years. In the 50-69 and 70 + age groups, significant declines of -4.1% and - 8.4% respectively were found. Excess declines were seen in clinical stage 0 and I in Mar-Jun, without excess increases in clinical stage II-IV tumors in Jul-Dec. There was no increase in average tumor diameter or nodal involvement in 2020. Patients diagnosed in Mar-Jun received significantly more neoadjuvant therapy, particularly neoadjuvant hormonal therapy for patients with clinical stage I-II BC. CONCLUSIONS: BC incidence decline in 2020 in Belgium was largely restricted to very early-stage BC and patients aged 50 and over. Delayed diagnosis did not result in an overall progression to higher stage at diagnosis in 2020. Observed treatment adaptations in Belgium were successful in prioritizing patients for surgery while preventing tumor progression in those with surgical delay. Continuation of monitoring BC incidence and stage in the future is crucial.

Quality of surgery and treatment and its association with hospital volume: A population-based study in more than 5000 Belgian ovarian cancer patients.

BACKGROUND: Different sets of quality indicators are used to identify areas for improvement in ovarian cancer care. This study reports transparently on how (surgical) indicators were measured and on the association between hospital volume and indicator results in Belgium, a country setting without any centralisation of ovarian cancer care. METHODS: From the population-based Belgian Cancer Registry, patients with a borderline malignant or invasive epithelial ovarian tumour diagnosed between 2014 and 2018 were selected and linked to health insurance and vital status data (n = 5119). Thirteen quality indicators on diagnosis and treatment were assessed and the association with hospital volume was analysed using logistic regression adjusted for case-mix. RESULTS: The national results for most quality indicators on diagnosis and systemic therapy were around the predefined target value. Other indicators showed results below the benchmark: genetic testing, completeness of staging surgery, lymphadenectomy with at least 20 pelvic/para-aortic lymph nodes removed, and timely start of chemotherapy after surgery (within 42 days). Ovarian cancer care in Belgium is dispersed over 100 hospitals. Lower volume hospitals showed poorer indicator results compared to higher volume hospitals for lymphadenectomy, staging, timely start of chemotherapy and genetic testing. In addition, surgery for advanced stage tumours was performed less often in lower volume hospitals. CONCLUSIONS: The indicators that showed poorer results on a national level were also those with poorer results in lower-volume hospitals compared to higher-volume hospitals, consequently supporting centralisation. International benchmarking is hampered by different (surgical) definitions between countries and studies.

Survival of patients with unfavorable prognosis cutaneous melanoma with increased use of immunotherapy agents: a population-based study in Belgium.

BACKGROUND: Although metastatic cutaneous melanoma is associated with an unfavorable prognosis, innovative therapies including immunomodulating agents and targeted therapies have shown survival benefits in clinical trials. We assessed the impact of the introduction of innovative drugs into clinical practice on the survival of patients with metastatic cutaneous melanoma during the period 2004-2017, in Belgium. The evolution of associated expenses was also analyzed. METHODS: This is a retrospective population-based study using data from the national Belgian Cancer Registry, compulsory health insurance, and administrative survival data. The immunomodulating drugs were ipilimumab, nivolumab and pembrolizumab, while targeted therapies included vemurafenib, dabrafenib and trametinib. RESULTS: We did not identify a trend for improvement over time. Median survival (years) was 1.5 (95% CI: 1.1-1.8) in 2004-2008, 1.1 (95% CI: 0.8-1.5) in 2009-2013, and 1.6 (95% CI: 1.3-2.4) in 2014-2017, respectively. In contrast, survival improved in those with unknown primary tumor localization. In this group, median survival time was 2.0 (95% CI: 1.4-2.9) in the most recent period, while it was 1.1 (95% CI: 0.7-1.3) in 2009-2013, and 0.9 (95% CI: 0.6-1.2) in 2004-2008. The uptake of innovative drugs remained modest, with no drug being used by more than 30% of patients. Yearly expenditure was almost non-existent, and gradually increased, reaching several million euros in 2014-2017. CONCLUSION: Patients with metastatic cutaneous melanoma who were diagnosed between 2004 and 2017 showed no apparent improvement in survival. In contrast, increased survival was observed in the subgroup of patients with unknown primary tumor localization.

Practice patterns, time trends and quality of care of uterine cancer in Belgium: An analysis of the EFFECT database.

OBJECTIVES: To investigate the practice patterns and quality of care for uterine cancer on a national level in Belgium, including trends in practice over the period 2012-2016. METHODS: Quality indicators were measured using the EFFectiveness of Endometrial Cancer Treatment (EFFECT) database. Multivariable logistic mixed regression was used to test for associations between the quality indicators and year of diagnosis, adjusted for potential confounders and intra-cluster correlations. RESULTS: The EFFECT database includes 4178 patients diagnosed with uterine cancer in the period 2012-2016. Minimally invasive surgery (laparoscopic or robotic-assisted) was applied in 61.6% of patients who had surgery for clinical stage I endometrial carcinoma (EC), increasing from 52.9% in 2012 to 66.4% in 2016. At least pelvic lymph node staging was performed in 69.0% of patients with clinical stage I, high-grade EC; and in 63.9% of patients with clinical stage I-II serous carcinoma, clear cell carcinoma or carcinosarcoma. The latter increased from 48.8% in 2012 to 77.2% in 2016. Adjuvant radiotherapy (external beam and/or brachytherapy) was offered to 33.5% of patients who had surgery without lymph node staging for pathological stage I EC at high-intermediate or high risk of recurrence. Adjuvant chemotherapy was administered to 64.4% of patients with pathological stage III-IVA EC. CONCLUSIONS: Study results indicate an overall good quality of care for patients with uterine cancer in Belgium. Treatment areas with potential room for improvement include the use of minimally invasive surgery, comprehensive surgical staging and adjuvant therapy, which confirms the remaining controversies in uterine cancer treatment and the need for further research.

Epidemiology and survival of adult-type diffuse glioma in Belgium during the molecular era.

BACKGROUND: Survival data of diffuse adult-type glioma is mostly based on prospective clinical trials or small retrospective cohort studies. Real-world data with large patient cohorts is currently lacking. METHODS: Using the nationwide, population-based Belgian Cancer Registry, all known histological reports of patients diagnosed with an adult-type diffuse glioma in Belgium between 2017 and 2019 were reviewed. The ICD-O-3 morphology codes were matched with the histological diagnosis. The gathered data were transformed into the 2021 World Health Organization classification of CNS tumors using the IDH- and 1p/19q-mutation status. RESULTS: Between 2017 and 2019, 2233 diffuse adult-type gliomas were diagnosed in Belgium. Full molecular status was available in 67.1% of identified cases. The age-standardized incidence rate of diffuse adult-type glioma in Belgium was estimated at 8.55 per 100 000 person-years and 6.72 per 100 000 person-years for grade 4 lesions. Median overall survival time in IDH-wild-type glioblastoma was 9.3 months, significantly shorter compared to grade 4 IDH-mutant astrocytoma (median survival time: 25.9 months). The 3-year survival probability was 86.0% and 75.7% for grades 2 and 3 IDH-mutated astrocytoma. IDH-wild-type astrocytoma has a worse prognosis with a 3-year survival probability of 31.6% for grade 2 and 5.7% for grade 3 lesions. CONCLUSIONS: This registry-based study presents a large cohort of adult-type diffuse glioma with known molecular status and uses real-world survival data. It adds to the current literature which is mainly based on historical landmark trials and smaller retrospective cohort studies.

Association between hospital volume and outcomes in invasive ovarian cancer in Belgium: A population-based study.

OBJECTIVES: To study the association between hospital volume and outcomes in patients with invasive epithelial ovarian cancer (EOC). METHODS: This study included 3988 patients diagnosed with invasive EOC between 2014 and 2018, selected from the population-based database of the Belgian Cancer Registry (BCR), and coupled with health insurance and vital status data. The associations between hospital volume and observed survival since diagnosis were assessed with Cox proportional hazard models, while volume associations with 30-day post-operative mortality and complicated recovery were evaluated using logistic regression models. RESULTS: Treatment for EOC was very dispersed with half of the 100 centres treating fewer than six patients per year. The median survival of patients treated in centres with the highest-volume quartile was 2.5 years longer than in those with the lowest-volume quartile (4.2 years versus 1.7 years). When taking the case-mix of hospitals into account, patients treated in the lowest volume centres had a 47% higher hazard to die than patients treated in the highest volume centres (HR: 1.47, 95% CI: 1.11-1.93, p = 0.006) over the first five years after incidence. A similar association was found when focussing on the surgical volume of the hospitals and considering only operated patients with invasive EOC. Lastly, the 30-day post-operative mortality decreased significantly with increasing surgical volume. CONCLUSIONS: The large dispersion of care and expertise within Belgium and the volume-outcome associations observed in this study support the implementation of the concentration of care for patients with invasive EOC in reference centres.

Stage shift and relative survival for head and neck cancer during the 2020 COVID-19 pandemic: a population-based study of temporal trends.

Objective: During the first wave of the COVID-19 pandemic in 2020, non-essential health services were suspended in Belgium, and the public was ordered to socially isolate. Underdiagnosis of cancer during this period was reported worldwide. Certain risk factors for head and neck cancer (HNC) overlap with those for COVID-19 incidence and mortality, making underdiagnosis and subsequent stage shift of this potentially rapidly progressing cancer a major concern. We aimed to analyze incidence, clinical stage at presentation, and survival of patients diagnosed with HNC in 2020 in Belgium, considering recent temporal trends. Methods: Using population-based data from the Belgian Cancer Registry (BCR), we extrapolated 2017-2019 trends in incidence, clinical stage, and 1-year relative survival (1yRS) of HNC to create an expected value for 2020 and compared this to the observed value. Results: There were 9.5% fewer HNCs diagnosed in 2020, compared to the predicted incidence. Underdiagnosis was larger for males (-11.8%), patients aged 50-64 (-11.2%) and 65-79 (-11.1%), and for oral cavity cancer (-17.6%). Shifts to more advanced stages were observed in larynx and oropharynx tumors and for (male) patients aged 80+. A 2.4 percentage point decline in 1yRS was observed, relative to the increasing trends in 1yRS (2017-2019). Conclusion: The COVID-19 pandemic led to underdiagnosis of HNC, resulting in shifts to more advanced stage at presentation in certain subgroups. A stage shift can be expected for the 9.5% of tumors not yet diagnosed at the end of 2020. HNC patients diagnosed in 2020 suffered higher than expected mortality.

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.

Long-term health-care utilisation in older patients with cancer and the association with the Geriatric 8 screening tool: a retrospective analysis using linked clinical and population-based data in Belgium.

BACKGROUND: Little evidence is available on the long-term health-care utilisation of older patients with cancer and whether this is associated with geriatric screening results. We aimed to evaluate long-term health-care utilisation among older patients after cancer diagnosis and the association with baseline Geriatric 8 (G8) screening results. METHODS: For this retrospective analysis, we included data from three cohort studies for patients (aged ≥70 years) with a new cancer diagnosis who underwent G8 screening between Oct 19, 2009 and Feb 27, 2015, and who survived more than 3 months after G8 screening. The clinical data were linked to cancer registry and health-care reimbursement data for long-term follow-up. The occurrence of outcomes (inpatient hospital admissions, emergency department visits, use of intensive care, contacts with general practitioner [GP], contacts with a specialist, use of home care, and nursing home admissions) was assessed in the 3 years after G8 screening. We assessed the association between outcomes and baseline G8 score (normal score [>14] or abnormal [≤14]) using adjusted rate ratios (aRRs) calculated from Poisson regression and using cumulative incidence calculated as a time-to-event analysis with the Kaplan-Meier method. FINDINGS: 7556 patients had a new cancer diagnosis, of whom 6391 patients (median age 77 years [IQR 74-82]) met inclusion criteria and were included. 4110 (64·3%) of 6391 patients had an abnormal baseline G8 score (≤14 of 17 points). In the first 3 months after G8 screening, health-care utilisation peaked and then decreased over time, with the exception of GP contacts and home care days, which remained high throughout the 3-year follow-up period. Compared with patients with a normal baseline G8 score, patients with an abnormal baseline G8 score had more hospital admissions (aRR 1·20 [95% CI 1·15-1·25]; p<0·0001), hospital days (1·66 [1·64-1·68]; p<0·0001), emergency department visits (1·42 [1·34-1·52]; p<0·0001), intensive care days (1·49 [1·39-1·60]; p<0·0001), general practitioner contacts (1·19 [1·17-1·20]; p<0·0001), home care days (1·59 [1·58-1·60]; p<0·0001), and nursing home admissions (16·7% vs 3·1%; p<0·0001) in the 3-year follow-up period. At 3 years, of the 2281 patients with a normal baseline G8 score, 1421 (62·3%) continued to live at home independently and 503 (22·0%) had died. Of the 4110 patients with an abnormal baseline G8 score, 1057 (25·7%) continued to live at home independently and 2191 (53·3%) had died. INTERPRETATION: An abnormal G8 score at cancer diagnosis was associated with increased health-care utilisation in the subsequent 3 years among patients who survived longer than 3 months. FUNDING: Stand up to Cancer, the Flemish Cancer Society.

The epidemiology of multiple primary cancers in Belgium (2004-2017): Incidence, proportion, risk, stage and impact on relative survival estimates.

BACKGROUND: As both life expectancy and cancer survival improve, the incidence of multiple primary cancer has augmented and is expected to further increase. This study describes for the first time the epidemiology of multiple invasive tumours in Belgium. METHODS: This nationwide study, based on all cancers diagnosed between 2004 and 2017 in Belgium, describes the proportion of multiple primary cancer, its evolution over time, the impact of inclusion or exclusion of multiple primary cancer on relative survival estimates, the risk of developing a second primary cancer, and the difference in stage between first and second primary cancer for the same patient. RESULTS: The proportion of multiple primary cancer increases with age, varies across cancer sites (from 4% for testis cancer to 22.8% for oesophageal cancer), is higher in men than in women, and has linearly increased over time. The inclusion of multiple primary cancer resulted in smaller 5-year relative survival and this impact is more pronounced in cancer sites with high relative survival. Patients with a first primary cancer have an increased risk to develop a new primary cancer compared to the population without a previous cancer history (1.27 and 1.59 times higher in men and women, respectively) and this risk depends on cancer site. Second primary cancers are associated with more advanced stages and more unknown stages than the corresponding first cancer diagnosis. CONCLUSIONS: This study describes multiple primary cancer according to several measures (proportion, standardised incidence ratio for an second primary cancer, impact of multiple primary cancer on relative survival and differences according to stage) for the first time in Belgium. The results are based on data of a population-based cancer registry with a relatively recent onset (2004).

Belgian observational survival data (incidence years 2004-2017) and expenditure for innovative oncology drugs in twelve cancer indications.

BACKGROUND: The Food and Drug Administration and European Medicines Agency typically approve market access for cancer drugs based on surrogate end-points, which do not always translate into substantiated improvements in outcomes that matter the most to patients, i.e. survival and quality of life. These drugs often, also, have a high price tag. We assessed whether there was an increase in cancer drug expenditure for a broad selection of indications, and whether this correlates with increased overall survival. METHODS: This cohort study used Belgian Cancer Registry data from 125,692 patients (12 cancer indications, incidence period 2004-2017), which was linked to reimbursement and survival data. This reliably represents the Belgian situation. One-to-five year observed survival probability, median survival time, oncology drug expenditure and mean oncology drug cost per patient were reviewed. FINDINGS: In almost all indications, total expenditure and average treatment cost for oncology drugs increased over the years (2004-2017). In contrast, mixed findings are observed for the evolution in overall survival probability and median survival time. While an absolute improvement in the 3-year survival probability of about 10% is noticed in non-small-cell lung cancer and chronic myeloid leukaemia, improvements in about half of the other indications are limited or even absent. INTERPRETATION: The Belgian observational data indicate that assuming 'innovative' oncology drugs always add value in terms of improved survival is often unjustified. The literature also highlights the problem of using surrogate end-points, and the lack of comparative evidence showing an added value of oncology drugs for both survival and quality of life at market approval or during the post-marketing phase. Comparative studies should be conducted in the pre-marketing phase that are suitable for registration purposes, aid reimbursement decisions and support physicians and patients when making treatment decisions.

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.

Survival in stage IV ovarian cancer with increased use of debulking surgery and bevacizumab.

OBJECTIVES: Advanced ovarian cancer has a poor prognosis, with a 5 year survival probability of <30%. Attempts to improve survival have focused on debulking surgery and systemic therapy. We assessed the evolution of treatment patterns and survival of patients with advanced epithelial ovarian cancer with specific attention to changes in survival after introducing bevacizumab. METHODS: Population based data from the Belgian Cancer Registry were coupled with administrative reimbursement data from the compulsory health insurance organizations and the national database where date of death is registered, based on the patient's unique national number. Patients with epithelial ovarian cancer stage IV diagnosed in 2004-17 were included. The proportion of patients who underwent debulking surgery and received bevacizumab was calculated per incidence year. Survival was compared for the three incidence periods (2004-08, 2009-13, 2014-17) and before and after the introduction of bevacizumab. RESULTS: 2034 patients with stage IV epitheial ovarian cancer were included. From 2012 onwards, uptake of bevacizumab increased, with 50% of patients with stage IV ovarian cancer diagnosed in 2017 receiving bevacizumab. The proportion of stage IV patients who underwent debulking surgery also increased over time, from 21.1% in 2004-08 to 50.4% and 45.4% in 2009-13 and 2014-17, respectively. The 3 year observed survival probability fluctuated between 27% and 42% without a trend over time. The increase in debulking surgery was associated with improved survival (hazard ratio (HR) 0.88, 95% confidence interval (CI) 0.79 to 0.98) but the introduction of bevacizumab was not (HR 0.94, 95% CI 0.85 to 1.03). For patients diagnosed in 2004, the mean cost per patient treated with oncological drugs was about €12 500, which doubled to about €25 000 for patients diagnosed in 2014 or later. CONCLUSIONS: Despite a rise in the use of debulking surgery and the introduction of bevacizumab into clinical practice, no improvement in 3 year survival probability was observed for patients with advanced ovarian cancer in Belgium.

A Population-Based Study Using Belgian Cancer Registry Data Supports Centralization of Esophageal Cancer Surgery in Belgium.

BACKGROUND: Esophageal cancer surgery outcomes benefit from higher hospital volumes. Despite the evidence, organization of national health care often is complex and depends on various factors. The volume-outcome results of this population-based study supported national health policy measures regarding concentration of esophageal resections in Belgium. METHODS: The Belgian Cancer Registry (BCR) database was linked to administrative data on cancer treatment. All Belgian patients with newly diagnosed esophageal cancer in 2008-2018 undergoing resection were allocated to the hospital at which surgery was performed. The study assessed hospital volume association with 90-day mortality and 5-year overall survival, classifying average annual hospital volume of resections as low (LV, <6), medium (MV, 6-19), or high (HV, ≥20) and as a continuous covariate in the regression models. RESULTS: The study included 4156 patients who had surgery in 79 hospitals (2 HV hospitals [37% of all surgeries], 12 MV hospitals [30% of all surgeries], and 65 LV hospitals [33% of all surgeries]). Adjusted 90-day mortality in HV hospitals was lower than in LV hospitals (odds ratio [OR], 0.37; 95% CI, 0.21-0.65; p = 0.001). Case-mix adjusted 5-year survival was superior in HV versus LV (hazard ratio [HR], 0.43; 95% CI, 0.31-0.60; p < 0.001). The continuous model demonstrated a lower 90-day mortality (OR, 0.40; 95% CI, 0.23-0.71; p = 0.002) and a superior 5-year survival (HR, 0.45; 95% CI, 0.33-0.63; p < 0.001) in hospitals with volumes of 40 or more resections annually. CONCLUSION: Population-based data from the BCR confirmed a strong volume-outcome association for esophageal resections. Improved 5-year survival in centers with annual volumes of 20 or more resections was driven mainly by the achievement of superior 90-day mortality. These findings supported centralization of esophageal resections in Belgium.

Impact of the COVID-19 Pandemic on Incidence and Observed Survival of Malignant Brain Tumors in Belgium.

(1) Background: This study evaluates the impact of the COVID-19 pandemic on the incidence, treatment, and survival of adults diagnosed with malignant brain tumors in Belgium in 2020. (2) Methods: We examined patients aged 20 and older with malignant brain tumors (2004-2020) from the Belgian Cancer Registry database, assessing incidence, WHO performance status, vital status, and treatment data. We compared 2020 incidence rates with projected rates and age-standardized rates to 2015-2019. The Kaplan-Meier method was used to assess observed survival (OS). (3) Results: In 2020, there was an 8% drop in age-specific incidence rates, particularly for those over 50. Incidence rates plunged by 37% in April 2020 during the first COVID-19 peak but partially recovered by July. For all malignant brain tumors together, the two-year OS decreased by four percentage points (p.p.) in 2020 and three p.p. in 2019, compared to that in 2015-2018. Fewer patients (-9 p.p.) with glioblastoma underwent surgery, and the proportion of patients not receiving surgery, radiotherapy, or systemic therapy increased by six percentage points in 2020. (4) Conclusions: The COVID-19 pandemic profoundly impacted the diagnosis, treatment strategies, and survival of brain tumor patients in Belgium during 2020. These findings should guide policymakers in future outbreak responses, emphasizing the need to maintain or adapt (neuro)-oncological care pathways and promote informed decision making when care capacity is limited.

Completeness and selection bias of a Belgian multidisciplinary, registration-based study on the EFFectiveness and quality of Endometrial Cancer Treatment (EFFECT).

BACKGROUND: With the aim of obtaining more uniformity and quality in the treatment of corpus uteri cancer in Belgium, the EFFECT project has prospectively collected detailed information on the real-world clinical care offered to 4063 Belgian women with primary corpus uteri cancer. However, as data was collected on a voluntary basis, data may be incomplete and biased. Therefore, this study aimed to assess the completeness and potential selection bias of the EFFECT database. METHODS: Five databases were deterministically coupled by use of the patient's national social security number. Participation bias was assessed by identifying characteristics associated with hospital participation in EFFECT, if any. Registration bias was assessed by identifying patient, tumor and treatment characteristics associated with patient registration by participating hospitals, if any. Uni- and multivariable logistic regression were applied. RESULTS: EFFECT covers 56% of all Belgian women diagnosed with primary corpus uteri cancer between 2012 and 2016. These women were registered by 54% of hospitals, which submitted a median of 86% of their patients. Participation of hospitals was found to be biased: low-volume and Walloon-region centers were less likely to participate. Registration of patients by participating hospitals was found to be biased: patients with a less favorable risk profile, with missing data for several clinical-pathological risk factors, that did not undergo curative surgery, and were not discussed in a multidisciplinary tumor board were less likely to be registered. CONCLUSIONS: Due to its voluntary nature, the EFFECT database suffers from a selection bias, both in terms of the hospitals choosing to participate and the patients being included by participating institutions. This study, therefore, highlights the importance of assessing the selection bias that may be present in any study that voluntarily collects clinical data not otherwise routinely collected. Nevertheless, the EFFECT database covers detailed information on the real-world clinical care offered to 56% of all Belgian women diagnosed with corpus uteri cancer between 2012 and 2016, and may therefore act as a powerful tool for measuring and improving the quality of corpus uteri cancer care in Belgium.

The non-fatal burden of cancer in Belgium, 2004-2019: a nationwide registry-based study.

BACKGROUND: The importance of assessing and monitoring the health status of a population has grown in the last decades. Consistent and high quality data on the morbidity and mortality impact of a disease represent the key element for this assessment. Being increasingly used in global and national burden of diseases (BoD) studies, the Disability-Adjusted Life Year (DALY) is an indicator that combines healthy life years lost due to living with disease (Years Lived with Disability; YLD) and due to dying prematurely (Years of Life Lost; YLL). As a step towards a comprehensive national burden of disease study, this study aims to estimate the non-fatal burden of cancer in Belgium using national data. METHODS: We estimated the Belgian cancer burden from 2004 to 2019 in terms of YLD, using national population-based cancer registry data and international disease models. We developed a microsimulation model to translate incidence- into prevalence-based estimates, and used expert elicitation to integrate the long-term impact of increased disability due to surgical treatment. RESULTS: The age-standardized non-fatal burden of cancer increased from 2004 to 2019 by 6 and 3% respectively for incidence- and prevalence-based YLDs. In 2019, in Belgium, breast cancer had the highest morbidity impact among women, followed by colorectal and non-melanoma skin cancer. Among men, prostate cancer had the highest morbidity impact, followed by colorectal and non-melanoma skin cancer. Between 2004 and 2019, non-melanoma skin cancer significantly increased for both sexes in terms of age-standardized incidence-based YLD per 100,000, from 49 to 111 for men and from 15 to 44 for women. Important decreases were seen for colorectal cancer for both sexes in terms of age-standardized incidence-based YLD per 100,000, from 105 to 84 for men and from 66 to 58 for women. CONCLUSIONS: Breast and prostate cancers represent the greatest proportion of cancer morbidity, while for both sexes the morbidity burden of skin cancer has shown an important increase from 2004 onwards. Integrating the current study in the Belgian national burden of disease study will allow monitoring of the burden of cancer over time, highlighting new trends and assessing the impact of public health policies.