P11.28.A Cancer registration and adherence to the WHO 2016 classification of pathology reports for astrocytic tumors in Belgium from 2017 to 2019

Background

The objective of this study is to cross-check the ICD-O-3 topography and morphology codes of registered glioma patients with findings in their pathology reports and to investigate the integration of relevant molecular markers in the final histopathological diagnosis.

Materials and methods

Since information regarding molecular tests and corresponding conclusions are not available as structured data at the Belgian population level a manual screening of all pseudonymized full text pathology reports available at the Belgian Cancer Registry (BCR) for adult glioma patients diagnosed between 2017 and 2019 was conducted. ICD-O-3 morphology and topography codes from the BCR database (provided by the hospital oncological care programs and laboratories for histopathology), were cross-checked with the data from the pathology reports. Relevant molecular markers were manually extracted from the pathology reports of confirmed glial tumors. The final diagnosis as mentioned in the reports and the integration of the appropriate molecular markers were checked against the WHO 2016 classification.

Results

For 1.892 of 2.379 registered gliomas (73%), a specific topographic code was provided. For 8% of patients registered with code C71.9 (unspecified region of the brain), a change to a specific topography code was implemented based on details in the pathology reports. For only 98 of 2.186 patients (4,5%) with available pathology reports, the ICD-O-3 morphology code was adjusted based on the information in the pathology reports. For 59 patients this was a change of grade within the same tumor group. In the subgroup of patients with astrocytic tumors, for 314 of 1.887 patients (16,6%) the IDH status (IDH1-IHC or IDH1/2-NGS) was not identifiable in the available reports. For only 1.091 of 1.887 patients (57,8%) the reports provided an integrated diagnosis including molecular findings, while for the other reports the tumor was not specified (NOS) in the conclusion. For 1.309 of 1.887 patients (69,4%), the final diagnosis in the pathology reports was compatible with the molecular markers. For 553 (29%) patients this was not the case because the relevant molecular markers were not integrated in the conclusion although available (i.e. in the conclusion of these pathology reports the tumor was NOS, but details of the molecular test result were however available somewhere in the reports).

Conclusion

Morphology codes of registered glioma are largely in line with findings in the pathology reports. The use of specific ICD-O-3 topography codes should be further encouraged and also molecular testing and the use of the integrated diagnosis in the pathology reports can be improved. These findings will be further processed and incorporated in the ongoing Quality Indicator project for glioma in Belgium and will be used to develop strategies to further optimize the reporting of these tumors towards the BCR.

Irregular screening participation increases advanced stage breast cancer at diagnosis: A population-based study

OBJECTIVE

To evaluate the effect of irregular screening behaviour on the risk of advanced stage breast cancer at diagnosis in Flanders.

METHODS

All women aged 50-69 who were invited to the organized breast cancer screening and diagnosed with breast cancer before age 72 from 2001 to 2018 were included. All prevalent screen and interval cancers within 2 years of a prevalent screen were excluded. Screening behaviour was categorized based on the number of invitations and performed screenings. Four groups were defined: regular, irregular, only-once, and never attenders. Advanced stage cancer was defined as a stage III + breast cancer. The association between screening regularity and breast cancer stage at diagnosis was evaluated in multivariable logistic regression models, taking age of diagnosis and socio-economic status into account.

RESULTS

In total 13.5% of the 38,005 breast cancer cases were diagnosed at the advanced stage. Compared to the regular attenders, the risk of advanced stage breast cancer for the irregular attenders, women who participated only-once, and never attenders was significantly higher with OR_adjusted:1.17 (95%CI:1.06-1.29) and OR_adjusted:2.18 (95%CI:1.94-2.45), and OR_adjusted:5.95 (95%CI:5.33-6.65), respectively.

CONCLUSIONS

In our study, never attenders were nearly six times more likely to be diagnosed with advanced stage breast cancer than regular attenders, which was much higher than the estimates published thus far. An explanation for this is that the ever screened women is a heterogeneous group regarding the participation profiles which also includes irregular and only-once attenders. The benefit of regular screening should be informed to all women invited for screening.

Factors associated with organized and non-organized colorectal cancer screening

Background

Data on non-organized colorectal cancer screening using fecal occult blood tests (FOBTs) is currently lacking. We identified factors associated with organized and non-organized FOBT screening.

Methods

Data of 308 municipalities in Flanders (6.6 million residents, 57% of Belgium) during 2015-2017 were analyzed. Logistic regression with generalized estimating equations was used to assess associations between municipal characteristics and organized and non-organized screening coverages.

Results

Median organized screening coverage increased (36.4% to 40.1%) while non-organized screening coverage decreased (4.8% to 3.3%) in 2015-2017. Organized screening coverage was negatively associated with average income (OR = 0.97, 95%CI: 0.96-0.98) and percentage of people with a non-Belgian/Dutch nationality (OR = 0.962, 95%CI: 0.957-0.967). More older people (70-74) in the target screening population were related to lower coverages by both organized (OR = 0.98, 95%CI: 0.97-0.99) and non-organized screening (OR = 0.98, 95%CI: 0.96-0.999). Education level was positively associated with organized screening coverage (OR = 1.010, 95%CI: 1.008-1.011). While GP visit was positively associated with both organized and non-organized screening coverages, average number of patients per GP and having a global medical dossier handled by preferred GP showed more pronounced associations with non-organized screening (OR = 1.021, 95%CI: 1.016-1.026 and OR = 1.025, 95%CI: 1.018-1.031, respectively) compared to organized screening coverage.

Conclusions

Higher average income, lower average education level, more older people and people with foreign nationality were associated with lower organized screening coverage. GP involvement showed a positive association with non-organized screening. It seems that some GPs and screening-invited individuals are still not fully aware of the benefits of organized screening. Available instruments in screening programs should be optimized to fill this gap in knowledge.

Key messages

We identified factors associated with both organized and non-organized colorectal cancer screening using fecal occult blood tests (FOBTs). Based on this knowledge, strategies can be developed to promote screening among non-participants and encourage non-organized participants to switch to organized screening.

P14.22 Quality indicators in neuro-oncology: modified Delphi process for the development of a quality indicator set for assessment of glioma care

BACKGROUND

Quality Indicators (QIs) are important tools to assess the quality and variability of oncological care. However, their application in neuro-oncology is limited. The objective of this study was to develop a set of QIs for glioma, covering process and outcome indicators.

METHODS

First a systematic literature search was performed in peer-reviewed papers and grey literature to identify existing QIs in neuro-oncology and guidelines or recommendations that could be translated into new QIs. The PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) checklist and flow diagram were taken into account. The search strategy focused on diagnostics, treatment, follow-up and survival. For each (set of similar) recommendation(s) a QI was created that could easily be translated into a measurable proportion. Concordant QIs were rationalized to further reduce redundancy. Secondly a two round Delphi survey was organized amongst a multidisciplinary expert panel that was asked to score relevance for all proposed QIs. The panel consisted of neurosurgeons(4), radiation(3) and medical(3) oncologists, pathologists(3), radiologists(2), neurologists(1), nuclear medicine physicians(2) from university and non-university centers, and representatives of the Belgian Cancer Registry.

RESULTS

The conducted literature search in PubMed and Embase yielded 2392 abstracts. After screening and duplicate removal, 221 full text articles were assessed of which 79 were retained. In addition 28 references from the Grey literature were added. In total 240 recommendations and 30 QIs could be identified in this way. After translation of these recommendations into a measurable proportion, merging with the QIs found as such in the literature and rationalization, 148 QIs were presented to the expert panel. In the Delphi survey 15 of the 19 (79%) invited experts responded and eventually consensus was reached on 46 QIs that were considered relevant for the assessment of 6 different domains of neuro-oncological care: diagnosis and imaging (10), surgery (4), pathology (6), radio/chemotherapy (14), recurrence (5) and supportive treatment (7).

CONCLUSION

A set of 46 QIs grouped in 6 categories to assess the quality of care of glioma patients was developed. These QI’s are readily applicable dependent on the availability of population-based health care data

Decline and incomplete recovery in cancer diagnoses during the COVID-19 pandemic in Belgium: a year-long, population-level analysis

BACKGROUND

Oncological care was considerably impacted by the COVID-19 pandemic. Worrisome declines in diagnostic procedures and cancer diagnoses in 2020 have been reported; however, nationwide, population-based evidence is limited. Quantification of the magnitude and distribution of the remaining outstanding diagnoses is likewise lacking.

METHODS

Using accelerated delivery of data from pathology laboratories to the Belgian Cancer Registry, we compared the nationwide rates of new diagnoses of invasive cancers in 2020 to 2019.

RESULTS

We observed a 44% reduction in total diagnoses of invasive cancers in April 2020 compared with April 2019, coinciding with the first wave of the COVID-19 pandemic. The reduction was largest in older patients and for skin cancers (melanoma and nonmelanoma). Reductions in diagnosis were less pronounced among children and adolescents (0-19 years). A smaller decline was observed for most cancers with typically poorer prognosis or obvious symptoms, including some hematological malignancies, lung, and pancreatic cancer. Suspension of organized population screening programs was reflected in a strong decline in diagnosis in the screening age groups for female breast cancer (56%) and for colorectal cancer in both men (49%) and women (60%). The number of diagnoses began to increase from the end of April and stabilized at the beginning of June at or just above 2019 levels. There has yet to be a complete recovery in cancer diagnoses, with an estimated 6%, or ∼4000 diagnoses, still outstanding for all of 2020. Among solid tumors, head and neck cancers have the largest remaining year-over-year decrease in diagnoses at 14%.

CONCLUSION

These results add to the evidence of a profound impact of the COVID-19 pandemic on oncological care and identify groups at risk for continuing diagnostic delays. These data should stimulate health care providers worldwide to facilitate targeted, accessible, and efficient procedures for detection of cancers affected by this delay.

External Validation of the Dutch SOURCE Survival Prediction Model in Belgian Metastatic Oesophageal and Gastric Cancer Patients

The SOURCE prediction model predicts individualised survival conditional on various treatments for patients with metastatic oesophageal or gastric cancer. The aim of this study was to validate SOURCE in an external cohort from the Belgian Cancer Registry. Data of Belgian patients diagnosed with metastatic disease between 2004 and 2014 were extracted (n = 4097). Model calibration and discrimination (c-indices) were determined. A total of 2514 patients with oesophageal cancer and 1583 patients with gastric cancer with a median survival of 7.7 and 5.4 months, respectively, were included. The oesophageal cancer model showed poor calibration (intercept: 0.30, slope: 0.42) with an absolute mean prediction error of 14.6%. The mean difference between predicted and observed survival was −2.6%. The concordance index (c-index) of the oesophageal model was 0.64. The gastric cancer model showed good calibration (intercept: 0.02, slope: 0.91) with an absolute mean prediction error of 2.5%. The mean difference between predicted and observed survival was 2.0%. The c-index of the gastric cancer model was 0.66. The SOURCE gastric cancer model was well calibrated and had a similar performance in the Belgian cohort compared with the Dutch internal validation. However, the oesophageal cancer model had not. Our findings underscore the importance of evaluating the performance of prediction models in other populations.

Abstract P1-08-31: Comparing estimates of survival for breast cancer patients

Introduction

Net survival can be considered as the most accurate evaluation of survival from cancer, as it encompasses the survival that would occur if the only possible underlying cause of death was the cancer under study. Both relative survival (RS) and cause-specific survival (CSS) have been developed as approaches to estimate net survival at the population level. Given the debated accuracy of death certificates in identifying the underlying cause of death, RS measures are most commonly used by cancer registries. However, RS calculations can also be biased as it is sometimes unavoidable to match a group of cancer patients with a non-comparable disease-free population group.

In this study, we aim to compare RS and CSS using causes of death obtained from death certificates in a cohort of Belgian breast cancer patients by evaluating them to CSS using causes of death obtained from medical files.

Methods

A total of 3,205 breast cancer patients diagnosed and treated in University Hospitals Leuven between 2009-2014 were included in this study. RS was calculated with the Ederer II method, dividing the observed survival by the expected survival for females of the same age and region. CSS was calculated using cause of death information either gathered from death certificates or collected from medical files. The estimates for RS and CSS as obtained from death certificates were compared to CSS obtained from medical files. Follow-up was guaranteed until 31th of December 2014.

Results

From the included cohort of breast cancer patients, 255 were deceased. Cause of death was available for 254 patients from death certificates and for 191 patients from medical files. By considering the available cause of death information, 3,141 patients were included to calculate the survival estimates. The 1-year relative survival estimate was 99.3% (95%CI, [98.7, 99.8]), while 1-year cause-specific survival based on death certificates was 99.0% [98.5, 99.3]. The 1-year survival estimate according to CSS based on medical files was 98.1% [97.5, 98.5]. The 5-year survival estimates were 95.8% [94.0, 97.4] for RS, 93.3% [91.8, 94.4] for CSS based on death certificates and 89.7% [88.0, 91.2] for CSS based on medical files.

Conclusion

This study used causes of death information as derived directly from medical files to calculate CSS in order to compare it with RS and CSS derived from death certificates. This allowed an evaluation of the RS and CSS estimates commonly used at the population level against the presumably more reliable CSS as obtained from medical files. Both RS and CSS from death certificates were divergent from CSS from medical files, but the CSS from death certificates appeared to be a closer estimate to CSS from medical files. After longer follow-up, both survival estimates seemed to deviate more from the CSS from medical files.

Citation Format: Izci H, De Schutter H, Wildiers H, Neven P. Comparing estimates of survival for breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-31.

Quality of pathology reporting is crucial for cancer care and registration: a baseline assessment for breast cancers diagnosed in Belgium in 2008

OBJECTIVES

Given the crucial role of pathology reporting in the management of breast cancers, we aimed to investigate the quality and variability of breast cancer pathology reporting in Belgium.

MATERIALS AND METHODS

Detailed information on non-molecular and molecular parameters was retrieved from the pathology protocols available at the Belgian Cancer Registry for 10,007 breast cancers diagnosed in Belgium in 2008.

RESULTS

Substantial underreporting was shown for several clinically relevant non-molecular parameters, such as lymphovascular invasion. High-volume laboratories performed only slightly better than others, and analyses at the individual laboratory level showed clear inter-laboratory variability in reporting for all volume categories. Information on ER/PR and HER2 IHC was mentioned in respectively 91.7% and 90.8% of evaluative cases. HER2 ISH data were available for 78.5% of the cases judged to be 2+ for HER2 IHC. For cases with different specimens analysed, discordance between these specimens was highest for HER2, followed by PR. For HER2, results obtained from different laboratories were even less concordant. In addition, inter-laboratory differences were noted in the used ER/PR scoring systems, the proportion of ER-/PR+ cases, and the relation between histological grade and ER/PR positivity. Data on Ki67 were only available for 43.8% of the investigated cases, and showed inconsistent use of cut-off values.

CONCLUSION

Breast pathology reporting in Belgium in 2008 was suboptimal and showed considerable inter-laboratory variability. Synoptic reporting has been proposed as a facilitator towards increased reporting quality and harmonization, but the lack of aligned informatics remains a major hurdle in its concrete implementation.

Evaluation of the quality of the management of cancer of the corpus uteri--selection of relevant quality indicators and implementation in Belgium

OBJECTIVE

Describe the methodology and selection of quality indicators (QI) to be implemented in the EFFECT (EFFectiveness of Endometrial Cancer Treatment) project. EFFECT aims to monitor the variability in Quality of Care (QoC) of uterine cancer in Belgium, to compare the effectiveness of different treatment strategies to improve the QoC and to check the internal validity of the QI to validate the impact of process indicators on outcome.

METHODS

A QI list was retrieved from literature, recent guidelines and QI databases. The Belgian Healthcare Knowledge Center methodology was used for the selection process and involved an expert's panel rating the QI on 4 criteria. The resulting scores and further discussion resulted in a final QI list. An online EFFECT module was developed by the Belgian Cancer Registry including the list of variables required for measuring the QI. Three test phases were performed to evaluate the relevance, feasibility and understanding of the variables and to test the compatibility of the dataset.

RESULTS

138 QI were considered for further discussion and 82 QI were eligible for rating. Based on the rating scores and consensus among the expert's panel, 41 QI were considered measurable and relevant. Testing of the data collection enabled optimization of the content and the user-friendliness of the dataset and online module.

CONCLUSIONS

This first Belgian initiative for monitoring the QoC of uterine cancer indicates that the previously used QI selection methodology is reproducible for uterine cancer. The QI list could be applied by other research groups for comparison.

Promoter methylation of TIMP3 and CDH1 predicts better outcome in head and neck squamous cell carcinoma treated by radiotherapy only

As with other solid tumor types, head and neck squamous cell carcinoma (HNSCC) has been identified as an epigenetic, as well as genetic, disease. Consequently, promoter hypermethylation, being the most important aberrant epigenetic characteristic, has been intensively investigated for its biomarker potential in this cancer type. As many of these evaluations are obscured by a heterogeneity of treatments, the current study aimed to evaluate the incidence and prognostic value of the promoter hypermethylation of TIMP3, CDH1, DAPK, RASSF1A, p16INK4A and MGMT in HNSCC treated solely by radiotherapy. In 46 patients with advanced HNSCC treated with a hybrid accelerated fractionation radiotherapy schedule, DNA extracted from pretreatment paraffin-embedded tumor biopsies was used to determine the methylation status of the genes of interest by methylation-specific PCR (MSP). The detected epigenetic silencing was related with outcome in terms of locoregional control (LRC), and overall (OS), disease-free (DFS) and disease-specific survival (DSS). Tumor biopsies revealed the epigenetic silencing of MGMT in 42.5% (17 of 40) of patients and of TIMP3 in 40.5% (17 of 42) of cases. For the remaining investigated genes, a lower methylation percentage was detected: 13.2% (5 of 38) for CDH1, 11.4% (4 of 44) for DAPK, 4.8% (2 of 42) for p16INK4A and 2.4% (1 of 41) for RASSF1A. The promoter hypermethylation of TIMP3 and CDH1 was significantly related with better LRC (p=0.009 and p=0.02, respectively), OS (p=0.005 and p=0.002, respectively), DFS (p=0.02 and p=0.004, respectively) and DSS (p=0.12 and p=0.007, respectively). In conclusion, in this representative group of 46 patients with advanced HNSCC treated by radiotherapy only, the epigenetic silencing of TIMP3 and CDH1 predicted a better outcome.

A new approach to the validation of tissue microarrays

Although tissue microarrays (TMA) have been widely used for a number of years, it is still not clear how many core biopsies should be taken to determine a reliable value for percentage positivity or how much heterogeneity in marker expression influences this number. The first aim of this study was to validate the human visual semi-quantitative scoring system for positive staining of tumour tissue with the exact values determined from computer-generated images. The second aim was to determine the minimum number of core biopsies needed to estimate percentage positivity reliably when the immunohistochemical staining pattern is heterogeneous and scored in a non-binary way. Tissue sections from ten colorectal cancer specimens were stained for carbonic anhydrase IX (CA IX). The staining patterns were digitized and 400 artificial computer-generated images were generated to test the accuracy of the human scoring system. To determine the minimal number of core biopsies needed to account for tumour heterogeneity, 50 (artificial) core biopsies per section were taken from the tumoural region of the ten digitally recorded full tissue sections. Based on the semi-quantitative scores from the 50 core biopsies per section, 2500 x n (n = 1-10 core biopsies) experimental core biopsies were then generated and scores recorded. After comparison with field-by-field analysis from the tumoural region of the whole tissue section, the number of core biopsies that need to be taken to minimize the influence of heterogeneity could be determined. In conclusion, visual scoring accurately estimated the percentage positivity and the percentage tumour present in a section, as judged by comparison with the artificial images. The exact number of core biopsies that has to be examined to determine tumour marker positivity using TMAs is affected by the degree of heterogeneity in the expression pattern of the protein, but for most purposes at least four is recommended.