Incidence of testicular tumor subtypes according to the updated WHO classification, North Rhine-Westphalia, Germany, 2008-2013.

BACKGROUND: In 2016, the WHO introduced an updated classification for testicular tumors. The application of this updated classification to cancer registry data requires some recoding of tumors. OBJECTIVES: The aim of this study was to provide up-to-date population-based incidence estimates of subtypes of testicular germ cell tumors (TGCT) according to the updated classification. MATERIAL AND METHODS: We reviewed 2251 pathology reports (42.9%) out of 5252 testicular tumors at the cancer registry of North Rhine-Westphalia for the years 2008-2013. We used population counts to estimate age-standardized incidence rates per million person-years (EUROSTAT revised European Standard Population). RESULTS: The application of the updated WHO classification resulted in a recoding of 8.9% of all testicular tumors. While the recodings have no influence on the incidence of seminomatous and non-seminomatous TGCTs that include mixed TGCTs, they influence the incidence of individual histological types of seminomatous and non-seminomatous TGCTs. Among the 4935 testicular germ cell tumors (TGCT), 23.7% were mixed TGCTs. Overall, 46.9% of all mixed TGCTs included seminoma and age-standardized incidence rates were highest for the combination seminoma plus embryonal carcinoma (5.9 per million person-years) and embryonal carcinoma plus teratoma (4.9 per million person-years). The median age at diagnosis was higher for mixed TGCTs including seminoma (31 years) than those that did not include seminoma (28 years). DISCUSSION AND CONCLUSIONS: Population-based incidence time trends for seminomatous and non-seminomatous TGCTs that include mixed TGCTs are not distorted by the introduction of the WHO update. Trend distortions can only be expected if time trends of individual histological subtypes of the seminomatous and non-seminomatous TGCTs are examined.

Digital mammography screening: sensitivity of the programme dependent on breast density.

OBJECTIVES: To analyse the impact of breast density on the sensitivity of a population-based digital mammography screening programme (SP) as key evaluation parameter. METHODS: 25,576 examinations were prospectively stratified from ACR category 1 to 4 for increments of 25 % density during independent double reading. SP was calculated as number of screen-detected cancers divided by the sum of screen-detected plus interval cancers (24-months period) per ACR category, related to the first reading (a), second reading (b) and highest stratification if discrepant (c). Chi-square tests were used for comparison. RESULTS: Overall sensitivity of the programme was 79.9 %. SP in ACR 4 (a: 50 %, b: 50 %, c: 50 %) was significantly lower than in ACR 3 (a: 72.9 %, b: 79.4 %, c: 80.7 %, p < 0.001), ACR 2 (a: 83.9 %, b: 85.7 %, c: 83.2 %, p < 0.001) and ACR 1 (a: 100 %, b: 88.8 %, c: 100 %; p < 0.001). Frequencies of ACR 4 were a: 5.0 %, b: 4.3 %, c: 6.9 %. CONCLUSION: Digital mammography screening with independent double reading leads to a high overall SP. In the small group of women with breast density classified as ACR 4 SP is significantly reduced compared to all other ACR categories. KEY POINTS: • Overall sensitivity of a population-based digital mammography screening programme (SP) was 79.9 %. • In women with ACR 1, 2, or 3, SP ranged between 72.9 %-100 %. • ACR 4 was rare in participants (<7 %) and SP was only 50 %. • SP in ACR 4 differed significantly from ACR 3 (p < 0.001).

Reduction of Advanced Breast Cancer Stages at Subsequent Participation in Mammography Screening.

PURPOSE: The decline in advanced breast cancer stages is presumably the most relevant surrogate parameter in mammography screening. It represents the last step in the causal cascade that is expected to affect breast cancer-related mortality. To assess the effectiveness of population-based screening, we analyzed the 2-year incidence rates of advanced breast cancers between women participating in the initial and in the first subsequent round. MATERIALS AND METHODS: The study included data from 19,563 initial and 18,034 subsequent examinations of one digital screening unit (2008 - 2010). Data on tumor stages, detected by screening or within the following interval of two years (2-year incidence), were provided by the epidemiological cancer registry. Rates of all and combined UICC stages 2, 3 and 4 (advanced stages) were reported for a two-year period. Proportions were tested for significance by using chi-square tests (p < 0.001). RESULTS: The 2-year incidence rate of all stages was significantly lower in participants in subsequent screening than in initial screening (0.85 vs. 1.29 per 100 women (%); p < 0.0001). A significantly lower 2-year incidence of advanced stages was observed for subsequent screening compared to initial screening (0.26 % vs. 0.48 %; p = 0.0007). Among women aged 50 to 59 years, the incidence of advanced stages was less clearly different (0.21 % vs. 0.35 %; p = 0.07) than in women aged 60 to 69 years (0.31 % vs. 0.70 %; p = 0.0008). CONCLUSION: During the change from prevalent to incident phase mammography screening, a program impact is seen by a lower 2-year incidence of advanced breast cancers within subsequent compared to initial participants, predominately in women aged 60 to 69 years. KEY POINTS: • The incidence of advanced tumor stages represents the most relevant surrogate parameter for screening effectiveness. • For the first time the 2-year incidence of advanced breast cancer stages after subsequent mammography screening was analyzed. • We observed a significant effect of screening on the 2-year incidence of advanced stages, predominately in the age group 60 to 69 years.

[Cohort study of cancer incidence in patients with type 2 diabetes: record linkage of encrypted data from an external cohort with data from the epidemiological Cancer Registry of North Rhine-Westphalia]. / Kohortenstudie zur Krebsinzidenz bei Patienten mit Diabetes mellitus Typ 2 : Record Linkage von kryptografierten Daten einer externen Kohorte mit Daten des Epidemiologischen Krebsregisters Nordrhein-Westfalen.

INTRODUCTION: German epidemiologic cancer registries may store only encrypted personal identifiers. Thus, record linkage with secondary databases needs to be performed via procedures that are based on encrypted identifiers. In this paper, we describe the linkage of patient data from a statutory health insurance company (AOK NordWest) and from the Disease Management Program for diabetes mellitus type 2 with the database of the cancer registry. We report the cancer incidence in patients with type 2 diabetes (T2D). METHODS: Personal identifying variables of the patient cohort were encrypted before being sent electronically to the cancer registry and submitted to a probabilistic record linkage with registry data. The study included T2D patients who were residents of the Münster, Detmold, or Arnsberg districts and who were aged 40-79 years. Only primary cancers occurring between the date of enrolment and the censoring date (31 December 2010) were included. The standardized incidence ratio (SIR) was calculated relative to the number of incident cases expected on the basis of the averaged incidence rates in the general population. RESULTS: The record linkage took about 3 weeks of processing time. A total of 67,447 T2D (49.2 % men) cases were included for analyses. Incident cancer was diagnosed in 2,086 men and 1,578 women. Cohort members showed an elevated risk for cancer of the liver (SIR =1.86; 95% CI =1.47-2.31), pancreas (SIR = 1.62; 95 % CI =1.36-1.91), lung (SIR = 1.21; 95% CI 1.11-1.32), and uterus (SIR = 1.34; 95 % CI 1.08-1.65), and they were less likely to be diagnosed with prostate cancer (SIR =0.72; 95% CI = 0.65-0.79). DISCUSSION: The findings of this study suggest that record linkage of secondary databases with cancer registry data for research purposes can be effectively carried out in compliance with strict data-protection regulations.

[Evaluation of the impact of the mammography screening program on breast cancer mortality: feasibility study on linking several data sources in North Rhine-Westphalia]. / Evaluation der Auswirkungen des Mammographie-Screening-Programms auf die Brustkrebsmortalität : Machbarkeitsstudie zur Verknüpfung verschiedener Datenquellen in Nordrhein-Westfalen.

BACKGROUND: In the German Mammography Screening Program (MSP), women aged 50-69 years are offered X-ray-based mammography for the early detection of breast cancer (BC) every 2nd year. To maintain the licensing of the MSP, evidence of a positive benefit-risk assessment of the radiation-related health risk has to be provided. Therefore, long-term effects of the program have to be shown by evaluating the BC mortality reduction based on the MSP. A current feasibility study attempts to develop different data flow models to evaluate whether, based on current legislations on data confidentiality, secondary data routinely available in the German health system can be linked in such a way that they can be used for epidemiological evaluation studies. We present the"NRW model," which builds on procedures developed and evaluated in the Epidemiological Cancer Registry of North Rhine-Westphalia (EKR-NRW). METHODS: Data of the Association of Statutory Health Physicians in Westfalen-Lippe (KVWL) are used to enumerate the cohort of women in WL who are entitled to MSP participation and their use of curative mammography outside of the MSP. The EKR-NRW provides epidemiological and medical data on all BC cases in WL, on cohort mortality, and on causes of death. The central MSP database MaSc offers the screening history of all MSP participants. The established uniform encryption methods employed in the EKR-NRW are used for linking records from the three data sources in one data-merging center (DZS). To this end, data are first captured in standardized formats, variably aggregated and transferred in an encrypted format, checked for anonymity and diversity level in an encrypted form, and eventually stored in a factually anonymized manner in the evaluation center (ES). Researchers can obtain data sets with plain text epidemiological-medical data from the ES for analyses.

[Determination of interval cancer rates in the German mammography screening program using population-based cancer registry data]. / Ermittlung der Rate von Intervallkarzinomen im deutschen Mammographie-Screening-Programm mit Hilfe epidemiologischer Krebsregister.

GOAL: The evaluation of interval cancers (ICA) and false-negative diagnoses (FND) is important for the quality assurance of the mammography screening program (MSP) for women aged 50-69 years. We aimed to investigate ICA in the states of Lower Saxony (NDS) and North Rhine-Westphalia (NRW). ICA could be identified by record linkage of data from screening attendees (TN) with data from population-based cancer registries. The frequencies of ICA and FND are described, and problems in the categorization of ICA according to EU guidelines are discussed. METHODS: Record linkage in the cancer registries was performed with the encrypted data from 83,724 TN in NDS and 885,940 TN in NRW. ICA were identified; in NDS, ICA were categorized by the regional MSP reference center. RESULTS: In all, 208 ICA in NDS and 2.018 ICA in NRW were ascertained. In relation to the regional background incidence rate (IR), the relative ICA rates were 22.5%/26.7% in the first year after screening (recommendation of EU guidelines <30% of IR) and 55.6%/54.2% in the second year after screening (recommendation of EU guidelines <50% of IR). It was found that 17.3% of all categorized ICA in NDS were FND (recommendation of EU guidelines <20%). DISCUSSION: The relative ICA rates for the 2-year interval are consistent with the recommendations of the EU guidelines. Unlike in NDS, the categorization of ICA was not possible in NRW. The MSP needs the diagnostic mammograms of all ICA in order to identify FND. However, data protection regulations are hindering this process and nationwide comparability of FND is therefore not guaranteed. In NDS, the state government has enacted laws to facilitate the transfer of diagnostic mammograms to the MSP. There is need for this sort of action in other federal states too.

Cancer detection rates following enrolment in a disease management programme for type 2 diabetes.

AIMS/HYPOTHESIS: Recent prospective studies found an elevated cancer risk shortly after diabetes diagnosis, and this was probably due to increased ascertainment. This study investigated whether site-specific cancer risks are also raised following enrolment in a disease management programme for type 2 diabetes mellitus (DMP-DM2). METHODS: We linked records from a DMP-DM2 to population cancer registry data. The study period was from June 2003 to December 2009. Standardised incidence ratios (SIRs) were calculated for time intervals following DMP enrolment using the cancer incidence rates of the general source population. Additionally, Poisson regression with natural splines was used to assess time-dependent cancer incidence by diabetes duration. RESULTS: There were 2,034 first invasive cancer cases identified over 163,738 person-years of follow-up. Pancreatic cancer risk was significantly increased mainly in the first year after enrolment (SIR 1.62); the increment was only seen for patients in whom diabetes had been diagnosed less than 1 year before DMP-DM2 enrolment. Risk of endometrial cancer was similarly raised in the first year after DMP-DM2 enrolment among individuals newly diagnosed with diabetes but decreased rapidly thereafter. There was no time dependence in the incidence of cancers of the liver, lung, colon, breast and prostate. CONCLUSIONS/INTERPRETATION: Enrolment in a DMP-DM2 did not appear to induce ascertainment bias for most cancers. Cancer risks were initially increased, especially for pancreatic cancer, potentially as a result of reverse causality. Ascertainment bias and time-dependent incidence of cancer appear to be less of a problem in settings using DMP-like structures for the study of the association between diabetes duration, glucose-lowering medication and cancer incidence.

A practical framework for data management processes and their evaluation in population-based medical registries.

INTRODUCTION: We present a framework for data management processes in population-based medical registries. Existing guidelines lack the concreteness we deem necessary for them to be of practical use, especially concerning the establishment of new registries. Therefore, we propose adjustments and concretisations with regard to data quality, data privacy, data security and registry purposes. MATERIALS AND METHODS: First, we separately elaborate on the issues to be included into the framework and present proposals for their improvements. Thereafter, we provide a framework for medical registries based on quasi-standard-operation procedures. RESULTS: The main result is a concise and scientifically based framework that tries to be both broad and concrete. Within that framework, we distinguish between data acquisition, data storage and data presentation as sub-headings. We use the framework to categorise and evaluate the data management processes of a German cancer registry. DISCUSSION: The standardisation of data management processes in medical registries is important to guarantee high quality of the registered data, to enhance the realisation of purposes, to increase efficiency and to enable comparisons between registries. Our framework is destined to show how one central impediment for such standardisations - lack of practicality - can be addressed on scientific grounds.

[Linkage of secondary data with cancer registry data on the basis of encrypted personal identifiers - results from a pilot study in North Rhine-Westphalia]. / Abgleich von Sekundärdaten mit einem epidemiologischen Krebsregister auf der Basis verschlüsselter Personendaten - Ergebnisse einer Pilotstudie in Nordrhein-Westfalen.

BACKGROUND: The Cancer Registry of North-Rhine-Westphalia stores exclusively encrypted personal identifiers of registered cancer patients. Therefore, comparisons with secondary data sets can only be performed by record linkage procedures that are based on encrypted personal identifiers. We report on a pilot study which linked encrypted personal data from the disease management program for patients with diabetes mellitus type 2 (DMP-DM2) with the database of the EKR NRW in order to test the feasibility and efficiency of these record linkage procedures. METHODS: Personal identifying variables of the DMP records were encrypted in a 2-stage process before being sent electronically to the EKR NRW where they were subsequently submitted to a probabilistic record linkage with the registry data. The study included 27 450 participants who were insured at the AOK NordWest, residents of the district Münster and who were aged 40-79 years at the time of first enrolment to the DMP-DM2 between June 2003-July 2008. RESULTS: The electronic processing time of the semi-automatic record linkage procedure took about 24 h. Approximately 2% of the records had to be reviewed manually. After exclusion of prevalent cancer cases, multiple primaries and inadequate data, 26 742 participants (47.3% men; 52.7% women) remained in the data set. About 1 364 cohort members (759 men, 605 women) were diagnosed with cancer after submission to the disease management program. DISCUSSION: The DMP-DM2 records were encrypted and linked to cancer registry data with a moderate personnel and financial input and high efficiency. Linked records were instantly usable for epidemiological analyses. Experiences of the pilot study suggest that future linkage studies can further advance the level of data protection, without losses in efficiency, by moderately complex software modifications and amendments of the data flow.