VersKiK: Study protocol of an observational registry-based study on the current state of follow-up care and adherence to follow-up guidelines after cancer in childhood or adolescence

BACKGROUND

This article describes the study design of the quantitative part of the VersKiK study, The primary objectives of this study are to examine the occurrence of late effects in survivors of childhood or adolescent cancer (module 1), investigate health-related vulnerabilities and medical service utilization within this survivor group (modules 1 and 3), and assess the alignment between documented follow-up care for cardiological and audiological late effects with guideline recommendations, along with evaluating the extent of adherence among paediatric cancer survivors (module 3).

METHODS

This is a non-interventional retrospective observational cohort study. It is based on stochastically linked insurance claims data from approximately 150,000 statutory insured persons with information concerning around 25,000-30,000 cancer survivors recorded in the German Childhood Cancer Register (GCCR). To explore adherence to selected follow-up guidelines, intention to treat treatment data from clinical study groups for particular diagnostic entities will be additionally included.

DISCUSSION

The growing group of survivors after cancer in childhood and adolescence is representing a special population with an increasing demand for life-long healthcare services through relative high probability of late effects. Currently, there is a limited evidence in Germany on utilization of corresponding medical services and adherence to follow-up guidelines. With this study design, we are aiming to address these gaps and, consequently, suggest improvements to existing follow-up guidelines and follow-up care provision in Germany.

Increased cancer incidence in children after cardiac catheterization within the first 8 years of life, a single center experience between 1999 and 2013

Background

Children with congenital heart disease are exposed to ionising radiation early in their lives when tissue sensitivity for radiation is highest. This might provoke DNA fractures and cancer development. Our first study with an observation period from 1980–1998 showed a 4.4-fold increased cancer risk for children who had at least one cardiac catheterization in the first year of life.

Objectives

This study aimed to reassess the risk of cancer for children who underwent at least one cardiac catheterization between 1999 and 2013 with a follow-up of seven years.

Methods

This retrospective, single-center study included 2765 children who underwent at least one cardiac catheterization before eight years of age between January 1999 and December 2013. 1688 received their first cardiac catheterization in the first year of life, 1074 between first and eighth year of life. Catheterization and patient data were obtained from our database, and cancer diagnoses up to age 15 were matched with German Childhood Cancer Registry. For each tumor patient and for each of the 60 randomly selected control patients cumulative effective radiation doses were calculated.

Results

37667.16 person-years were evaluated. A total of ten patients developed a malignant tumor, while 5.82 were expected (SIR 1.72; CI 0.82–3.16; p=0.0722). Eight of these ten tumors developed in patients who received their first cardiac catheterization in the first year of life, while 3.99 were expected (SIR 2.0; CI 0.71–3.62; p=0.1095). The cancer group performed an average of 3.7 cardiac catheterizations per patient, with a mean cumulative effective dose of 24,79mSv. In the control group consisting of 60 patients, 2.1 cardiac catheterizations were performed per patient with an average cumulative effective dose of 21.04mSv. Three of the ten tumor patients have chromosomal abnormalities. The cancers observed are two leukemia, two lymphoma, two CNS tumors, one osteosarcoma, two nephroblastoma and one hepatoblastoma.

Conclusion

There is still an increased risk of cancer development for children with congenital heart disease exposed to ionizing radiation early in life. However, due to technical development and increased sensitivity to this fact, we observed a decrease in cancer disease compared to our previous study with catherization between 1980 and 1998.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Stiftung Kinderherz

Long-term care, care needs and wellbeing of individuals after cancer in childhood or adolescence (VersKiK): study protocol of a large scale multi-methods non-interventional study

BACKGROUND

It has been shown previously that a relevant proportion of childhood cancer survivors suffers from late effects, which are often directly related to the cancer itself or its therapy, resulting in particular follow-up needs, additionally burdening healthcare systems. Being diagnosed with cancer at a vulnerable stage of development, this group of cancer survivors is at comparatively higher risk of relapse or subsequent cancer. Although national and international follow-up guidelines based on treatment modalities have been developed, their implementation seems to leave room for improvement. Additionally, they lack a sufficient consideration of the survivors' psychosocial needs, affecting their adherence to them. The aim of the VersKiK study is to provide representative information on late effects in childhood and adolescence cancer survivors in Germany. The main research objectives are: (1) to describe the state of follow-up care among survivors after a cancer diagnosis in childhood or adolescence; (2) to quantify the occurrence of late effects among this group of survivors; (3) to examine the adherence to selected audiological and cardiological follow-up guidelines and to identify factors affecting it; (4) to explore actual follow-up needs of paediatric cancer survivors; (5) to review selected follow-up guidelines with the aim to improve and expand them.

METHODS

VersKiK is designed as a mixed-methods non-interventional study. We will use claims data from statutory health insurance companies in combination with individually linked population-based registry data from the German Childhood Cancer Registry (GCCR). This data base will permit us to quantify diagnoses and procedures in comparison to the general population as well as the adherence to existing follow-up guidelines. Additional information will be obtained through interviews with childhood and adolescence cancer survivors and their informal caregivers, as well as in focus groups with healthcare professionals.

DISCUSSION

The present study aims to research the actual needs of individuals after cancer diagnosis and treatment in childhood or adolescence - physical, psychological and organisational - in order to improve existing follow-up guidelines. These improvements might further positively affect not only actual care provided to paediatric cancer survivors, but also benefit healthcare systems in general while decreasing consequent medical visits in this group of patients.

TRIAL REGISTRATION

Registered at German Clinical Trial Register (ID: DRKS00025960 and DRKS00026092).

Development of heart failure in long-term survivors of childhood cancer: results from the cvss study

Background

Long-term survivors of childhood cancer (CCS) are at increased risk for cardiovascular sequelae, including heart failure (HF) as the largest non-malignant contributor to excess death. Yet, little is known about the risk factors, mechanisms of cardiac dysfunction and prevalence of different stages of HF in these patients.

Purpose

To investigate the development and prevalence of HF phenotypes in CCS compared to the general population.

Methods

The CVSS study is a prospective single-center cohort study investigating cardiovascular sequelae of CCS. Patients were eligible for the study when they were diagnosed with a neoplasia according to the International Classification of Childhood Cancer (ICCC 3) at an age prior to 15 years between 1980 and 1990, survived more than five years after initial cancer diagnosis and received antineoplastic treatment. Between 2013 and 2016, study individuals underwent a comprehensive, standardized clinical investigation in the CVSS cohort study including echocardiographic examination. HF was categorized as stages A to D according to current HF guidelines of the American Heart Association (AHA). A population-based sample free of cancer (age- and sex matched) serves as control group.

Results

From 1,002 individuals, all CCS with history of chemo- or radiotherapy and no subsequent neoplasia (n=877) were included (mean age 34.2 (±5.5) years, 44.7% (N=392) female). Age at diagnosis was 6.28 years (±4.24) and the mean interval from the date of diagnosis of cancer to the date of completion of baseline examination 28.5±3.2 years. Based on echocardiographic examination, clinical data and biomarker assessment, 26.6% of CCS were diagnosed with HF stage A, 21.1% with HF stage B and 2.1% with symptomatic HF, i.e. HF stage C/D. Importantly, prevalence of different HF stages varied strongly by specific tumor history. Compared to the population, the prevalence ratio (PR) was 1.16 [95% confidence interval 1.02/1.31] for stage A HF and 1.91 [1.63/2.23] for the composite of stage B to D HF in an age- and sex-adjusted Poisson regression model. Multivariable linear regression with the systolic marker left ventricular ejection fraction as dependent variable and adjustment for tumor entities, age, sex, and cardiovascular risk factors (CVRF) revealed a lower EF in patients with history of bone tumors (β −6.0 [−8.1/−3.0]), soft tissue sarcoma (β −2.2 [−4.1/−0.35]), leukemia (β −0.84 [−1.8/0.08]) and renal tumors (β −1.8 [−4.0/0.27]) compared to the population. In contrast, the same model for the diastolic marker E/E', showed an association only with CVRF, but not with tumor entities.

Conclusion

The prevalence of stage B to D HF was significantly higher among long-term CCS in the 3rd to 5th age decade compared to the population and varied strongly by tumor entity. Systolic dysfunction was primarily associated with history of tumor entities, whereas diastolic dysfunction was associated with the higher burden of CVRF in CCS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study is funded by the Deutsche Forschungsgemeinschaft (DFG) (SP 1381/2-1&2, FA 1038/2-1&2, WI 3881/2-1&2)

TCERG1L allelic variation is associated with cisplatin-induced hearing loss in childhood cancer, a PanCareLIFE study

In children with cancer, the heterogeneity in ototoxicity occurrence after similar treatment suggests a role for genetic susceptibility. Using a genome-wide association study (GWAS) approach, we identified a genetic variant in TCERG1L (rs893507) to be associated with hearing loss in 390 non-cranial irradiated, cisplatin-treated children with cancer. These results were replicated in two independent, similarly treated cohorts (n = 192 and 188, respectively) (combined cohort: P = 5.3 × 10-10, OR 3.11, 95% CI 2.2-4.5). Modulating TCERG1L expression in cultured human cells revealed significantly altered cellular responses to cisplatin-induced cytokine secretion and toxicity. These results contribute to insights into the genetic and pathophysiological basis of cisplatin-induced ototoxicity.

Treatment-related fertility impairment in long-term female childhood, adolescent and young adult cancer survivors: investigating dose-effect relationships in a European case-control study (PanCareLIFE)

STUDY QUESTION

Which chemotherapeutic agents and body site-specific radiation fields are dose-dependently associated with an increased risk of fertility impairment in long-term female childhood, adolescent and young adulthood (CAYA) cancer survivors?

SUMMARY ANSWER

Busulfan, lower abdominal radiotherapy (RT) and total body irradiation (TBI) seem to be associated with fertility impairment at any dose, whereas gonadotoxicity of melphalan and procarbazine is suggested at medium/high (>140 mg/m2) or high dose (>5600 mg/m2) therapy, respectively.

WHAT IS KNOWN ALREADY

Several treatment-related fertility deficits, as assessed by both self-reported outcomes and hormonal markers are known to occur following treatment of CAYA cancer. However, knowledge regarding precise dose-related estimates of these treatment-related risks are scarce.

STUDY DESIGN, SIZE, DURATION

The current case-control study was nested within the PanCareLIFE cohort study. In total, 1332 CAYA survivors from 8 countries, 9 institutions and 11 cohorts, participated in and contributed data to the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All participants were female 5-year CAYA cancer survivors. In total, 450 cases (fertility impaired survivors) and 882 matched controls (not fertility impaired survivors) were included. Fertility impairment was defined using both questionnaire data (primary or secondary amenorrhea; use of artificial reproductive techniques; unfulfilled wish to conceive) and hormonal data (FSH and anti-Müllerian hormone (AMH)). Multivariable logistic regression models were used to investigate the effect of (i) alkylating agent exposure, and (ii) dose categories for individual chemotherapeutic agents and for RT-exposed body sites.

MAIN RESULTS AND THE ROLE OF CHANCE

A positive dose-effect relationship between cyclophosphamide equivalent dose (CED) score and fertility impairment was found, with survivors with a CED score > 7121 mg/m2 being at a significantly increased risk of fertility impairment (odds ratio (95% CI) = 2.6 (1.9-3.6) P < 0.001). Moreover, cumulative dose variables of the following treatments were significantly associated with fertility impairment: busulfan, carmustine, cyclophosphamide, melphalan, procarbazine, lower abdominal RT and TBI. Busulfan, lower abdominal RT and TBI seem to be associated with fertility impairment at any dose, whereas gonadotoxicity of melphalan and procarbazine is suggested at medium/high (>140 mg/m2) or high dose (>5600 mg/m2) therapy, respectively.

LIMITATIONS, REASONS FOR CAUTION

Our study may have been subject to selection bias since data from about half of the original base cohorts were available for the current study. This could impact the generalizability of our study results.

WIDER IMPLICATIONS OF THE FINDINGS

We identified survivors at high risk for fertility impairment and, consequently, for a reduced or even absent reproductive life span. Both girls and young women who are about to start anti-cancer treatment, as well as adult female survivors, should be counselled about future parenthood and referred to a reproductive specialist for fertility preservation, if desired.

STUDY FUNDING/COMPETING INTEREST(S)

This study has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 602030. There are no competing interests.

TRIAL REGISTRATION NUMBER

n/a.

[Late effects following childhood cancer treatment : A special challenge for transition medicine]

BACKGROUND

Childhood cancer survivors are at risk of cancer- and treatment-related chronic health conditions. Since these sequelae may occur years after the end of treatment, many patients are already adults and have completed pediatric oncological care. Thus, successful transition is essential in order to ensure long-term surveillance.

OBJECTIVES

The present review outlines the most frequent late effects of childhood cancer treatment. Moreover, difficulties in transition of these patients are discussed and interdisciplinary models of care are presented.

RESULTS

Late effects following childhood cancer treatment occur in over two thirds of patients 30 years after the end of the oncological treatment and can affect different organs. The most frequent sequelae are endocrine disturbances, cardiac conditions, and subsequent neoplasms. Many late effects are effectively manageable if detected early. This necessitates an interdisciplinary approach as well as life-long surveillance.

CONCLUSIONS

Transition from pediatric to internal medicine care as well as a change in the focus of care, shifting from relapse centered follow-up to late-effects centered surveillance, constitute a special challenge for a successful transition of long-term childhood cancer survivors. Specialized late-effects survivorship clinics offering interdisciplinary care from pediatric oncologists, specialists of internal medicine, and further disciplines enable the early diagnosis and treatment of late-effects.

Incidence, Trends, and Survival of Children With Embryonal Tumors

BACKGROUND

Central nervous system (CNS) and non-CNS embryonal tumors occur principally in children and are rarely seen in adults. The incidence rates for rare entities such as atypical teratoid/rhabdoid tumors (AT/RT) or primitive neuroectodermal tumors in the CNS are rarely published. Incidence rates for certain subgroups, such as hepatoblastomas, have been increasing in some countries.

METHODS

Data of 8337 embryonal tumors, registered in children (0-14 years) between 1991 and 2012 (for AT/RT 2000-2012) in the population-based German Childhood Cancer Registry with complete national coverage were analyzed for incidence rates, time trends, and survival.

RESULTS

For most entities, the incidence rates were the highest for children <1 year. An important exception was medulloblastomas, which occurred mainly in 1- to 9-year-olds. Neuroblastomas and ganglioneuroblastomas as well as Wilms tumors (nephroblastomas) had the highest age standardized incidence rates (13.7 and 9.4 per million, respectively). A statistically significant increasing trend for hepatoblastomas (annual average percent change 4.6%) was detected. The survival probabilities varied between the diagnostic groups: primitive neuroectodermal tumors and AT/RT had the lowest and retinoblastomas the highest. The survival was dependent on the age at diagnosis, the most extreme examples being neuroblastomas, for which the survival probability declined steeply for children ≥1 year and medulloblastomas, for which the highest survival was seen for 10- to 14-year-olds.

CONCLUSIONS

This study presents a comprehensive overview of pediatric embryonal tumors from a well-established, complete nationwide cancer registry. Significant increasing trend for hepatoblastomas was detected for the first time in Europe.

Cancer spectrum and frequency among children with Noonan, Costello, and cardio-facio-cutaneous syndromes

Background:

Somatic mutations affecting components of the Ras-MAPK pathway are a common feature of cancer, whereas germline Ras pathway mutations cause developmental disorders including Noonan, Costello, and cardio-facio-cutaneous syndromes. These ‘RASopathies' also represent cancer-prone syndromes, but the quantitative cancer risks remain unknown.

Methods:

We investigated the occurrence of childhood cancer including benign and malignant tumours of the central nervous system in a group of 735 individuals with germline mutations in Ras signalling pathway genes by matching their information with the German Childhood Cancer Registry.

Results:

We observed 12 cases of cancer in the entire RASopathy cohort vs 1.12 expected (based on German population-based incidence rates). This corresponds to a 10.5-fold increased risk of all childhood cancers combined (standardised incidence ratio (SIR)=10.5, 95% confidence interval=5.4–18.3). The specific cancers included juvenile myelomonocytic leukaemia=4; brain tumour=3; acute lymphoblastic leukaemia=2; rhabdomyosarcoma=2; and neuroblastoma=1. The childhood cancer SIR in Noonan syndrome patients was 8.1, whereas that for Costello syndrome patients was 42.4.

Conclusions:

These data comprise the first quantitative evidence documenting that the germline mutations in Ras signalling pathway genes are associated with increased risks of both childhood leukaemia and solid tumours.

Risk of cancer incidence before the age of 15 years after exposure to ionising radiation from computed tomography: results from a German cohort study

The aim of this cohort study was to assess the risk of developing cancer, specifically leukaemia, tumours of the central nervous system and lymphoma, before the age of 15 years in children previously exposed to computed tomography (CT) in Germany. Data for children with at least one CT between 1980 and 2010 were abstracted from 20 hospitals. Cancer cases occurring between 1980 and 2010 were identified by stochastic linkage with the German Childhood Cancer Registry (GCCR). For all cases and a sample of non-cases, radiology reports were reviewed to assess the underlying medical conditions at time of the CT. Cases were only included if diagnosis occurred at least 2 years after the first CT and no signs of cancer were recorded in the radiology reports. Standardised incidence ratios (SIR) using incidence rates from the general population were estimated. The cohort included information on 71,073 CT examinations in 44,584 children contributing 161,407 person-years at risk with 46 cases initially identified through linkage with the GCCR. Seven cases had to be excluded due to signs possibly suggestive of cancer at the time of first CT. Overall, more cancer cases were observed (O) than expected (E), but this was mainly driven by unexpected and possibly biased results for lymphomas. For leukaemia, the SIR (SIR = O/E) was 1.72 (95 % CI 0.89-3.01, O = 12), and for CNS tumours, the SIR was 1.35 (95 % CI 0.54-2.78, O = 7). Despite careful examination of the medical information, confounding by indication or reverse causation cannot be ruled out completely and may explain parts of the excess. Furthermore, the CT exposure may have been underestimated as only data from the participating clinics were available. This should be taken into account when interpreting risk estimates.

[Cancer incidence rate after diagnostic X-ray exposure in 1976 - 2003 among patients of a university children's hospital]

PURPOSE

Although the carcinogenic effect of ionizing radiation is well known, knowledge gaps persist on the health effects of low-dose radiation, especially in children. The cancer incidence rate in a cohort of 92,957 children diagnosed using X-rays in the years 1976 - 2003 in the radiology department of a large university clinic was studied.

MATERIALS AND METHODS

Individual radiation doses per examination were reconstructed using an algorithm taking into account the dose area product and other exposure parameters together with conversion factors computed specifically for the equipment and protocols used in the radiology department. Incident cancer cases in the period 1980 - 2006 were identified via record linkage to the German Childhood Cancer Registry using pseudonymized data.

RESULTS

A total of 87 cancers occurred in the cohort between 1980 and 2006: 33 leukemia, 13 lymphoma, 10 brain tumors, and 31 other tumors. The standardized incidence ratio (SIR) for all cancers was 0.99 (95 % CI: 0.79 1.22). A dose-response relationship was not observed for all cancers, leukemia and lymphoma or solid tumors. The cancer risks for boys and girls did not differ.

CONCLUSION

No increase in the cancer incidence risk in relation to very low doses of diagnostic ionizing radiation was observed in this study. However, the results are compatible with a broad range of risk estimates.

Up-to-date monitoring of childhood cancer long-term survival in Europe: tumours of the sympathetic nervous system, retinoblastoma, renal and bone tumours, and soft tissue sarcomas

BACKGROUND

Prognosis for most types of childhood tumours has improved during the last few decades. In this article we estimate up-to-date period survival for less common, but important childhood malignancies in Europe.

METHODS

Using the database of the Automated Childhood Cancer Information System we calculated period estimates of 10-year survival for the 1995-1999 period for children aged 0-14 years diagnosed during 1985-1999 with tumours of the sympathetic nervous system (NS), retinoblastoma, renal tumours, bone tumours and soft tissue sarcomas in four European regions.

RESULTS

Ten-year period survival for 1995-1999 was 66% in children with tumours of the sympathetic NS, 96% for retinoblastoma, 87% for renal tumours, 58% for bone tumours and 61% for soft tissue sarcomas. The higher period estimates, as compared with cohort and complete estimates indicate recent improvement in survival for tumours of the sympathetic NS and to a lesser extent for retinoblastoma and renal tumours. Region-specific period survival estimates were lowest for Eastern Europe for renal, bone and soft tissue tumours, but not for the other two tumour groups.

CONCLUSION

There have been further improvements in the 1990s in long-term survival of children diagnosed with several malignancies, albeit to a different extent in different European regions.

Incidence of childhood cancer of the head and neck in Germany

BACKGROUND

Only very limited data are available in the literature on the incidence of childhood cancer of the head and neck worldwide.

METHODS

Based on data obtained from the national German Childhood Cancer Registry, a total of 370 malignancies of the head and neck in children under the age of 15 (199 boys and 171 girls), which were reported to this institution between 1994 and 2003, were analysed in this study.

RESULTS

The overall incidence of malignancies of specific sites of the head and neck in Germany is 4.48 per 100000 children. The most frequently observed entities, representing primary tumours, are soft tissue sarcomas (0.39/100000), lymphomas (0.09/100000) and thyroid carcinoma (0.07/100000). The most commonly affected organs are the thyroid (1.21/100000), orbita (0.91/100000), nasopharynx (0.66/100000), tonsils (0.43/100000) and paranasal sinuses (0.14/100000). Overall, boys are more frequently affected than girls; however, incidence increases in girls with age and exceeds that of boys in the age group between 10 and 14 years.

CONCLUSIONS

This is a first statistical evaluation detailing cumulative incidences of various histologic types of malignancies of the head and neck including age and gender distribution as well as organ-specific localization in children below the age of 15 in Germany.

Namensbasierte Identifizierung von Fällen mit türkischer Herkunft im Kinderkrebsregister Mainz

Until now few analyses of routine data relating to the health of migrants have been conducted in Germany. A major obstacle is that most data sources do not provide reliable information on the origin of migrants. While some sources contain the nationality of persons registered, this information does not allow one to identify migrants who have taken up German citizenship, i.e., a substantial part of second-generation migrants. In this paper we demonstrate how a computer-aided, name-based algorithm can be used to identify persons of Turkish origin in the German Childhood Cancer Registry in Mainz, Germany. The performance of the algorithm, as assessed against the gold standard of assessing names manually, was very good (sensitivity and specificity > or = 0.975). In total, we identified 1774 of the 37,259 cases in the registry as being of Turkish origin. The name algorithm proved to be a useful tool to identify Turkish migrants in routine data sources, thus avoiding potential bias due to changes in citizenship. This approach aims at improving migrant-sensitive health reporting and research in Germany. In future, additional information on migrant status should be obtained already during primary data collection so that health data for all migrant groups can be provided.

Elternbefragung zur Anwendung alternativer und komplementärer Behandlungsmethoden in der Kinderonkologie in Deutschland

BACKGROUND

There are no published data on the use of complementary and alternative medicine (CAM) in pediatric oncology in Germany.

PATIENTS/METHOD

All parents of children, who where diagnosed a disease registered in the German Childhood Registry in 2001 were sent a questionnaire to evaluate possible CAM-use.

RESULTS

1 602 questionnaires were sent to the families, from whom 1 063 sent the questionnaire back to us. They reported a 35 % CAM-use-rate. The probability to use CAM was positively influenced by preexisting experience with CAM, higher social level and poor prognosis. 71 % of the users discussed the CAM-use with a physician. The reason for CAM-use seldom was missing trust in conventional medicine. 89 % of the CAM-users would recommend CAM-use to other parents in a comparable situation.

CONCLUSIONS

The reported CAM-use rate of 35 % in pediatric oncology in Germany is as reported in the international literature for other European countries. Essential parts of CAM-advise and -prescription are done by non-professionals, so that there is a need to get competence in CAM in pediatric oncology in Germany.

Das Langzeit-Follow-up in der deutschen pädiatrischen Onkologie als Basis für die Durchführung von Studien mit Langzeitüberlebenden

BACKGROUND

In recent years, the long-term survival of childhood cancer patients has increased considerably. While this is desirable, more patients with late effects are to be expected and studies thereof become increasingly important. We will need to be able to stay in touch with as many former patients as possible in order to make a systematic and comprehensive long-term follow-up possible.

PATIENTS

Childhood cancer patients under 15 years of age at diagnosis resident in Germany and registered at the German Childhood Cancer Registry (GCCR).

METHODS

The GCCR has established a 3-phase procedure for follow-up. We developed principles for the long-term follow up of these patients. They are based on the many years of experience at the GCCR and were developed based on the long-standing collaboration between the therapy optimization studies (TOS) in the Society for Paediatric Oncology and Haematology (GPOH) and the GCCR.

RESULTS

Currently 8 012 adult survivors diagnosed before 2000 are under observation at the GCCR and could be contacted for studies. About half of the children diagnosed in the 1980ies still in follow-up have been under observation more than 14 years. When asked to personally extend the originally parental consent to data storage at the GCCR and the TOS at about 16 years of age, about 85 % of the patients agree.

CONCLUSIONS

Establishing an open-end, systematic long-term follow-up will provide a unique and broad basis for paediatric oncology in Germany to perform representative studies regarding long-term survival after childhood cancer in Germany in the long run.

Combining cohort and period methods for retrospective time trend analyses of long-term cancer patient survival rates

Assessing trends in long-term cancer patient survival is an essential component of monitoring progress against cancer by cancer registries. Traditional assessment of long-term survival (‘cohort analysis’) is very useful to disclose trends in long-term survival rates of patients diagnosed many years ago, but it does not allow the disclosure of recent trends in long-term survival rates. The latter can be achieved by an alternative method of survival analysis (‘period analysis’), which has been proposed a few years ago. On the other hand, unlike cohort analysis, period analysis does not provide estimates of long-term survival rates for patients diagnosed in the early years after initiation of cancer registration. In this paper, a method of retrospective analysis of time trends in long-term survival rates is introduced, which combines the advantages of both cohort and period analysis (‘mixed analysis’). This method thereby allows for a comprehensive monitoring of trends in long-term survival over an extended time span from the earliest to the most recent years of cancer registration. The use of the method is illustrated for retrospective time trend analyses of long-term survival of cancer patients in the United States with the 1973–1999 database of the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute.

Long-term results and risk profiles of patients in five consecutive trials (1979-1997) with stage 4 neuroblastoma over 1 year of age

During the last two decades new diagnostic and therapeutic tools have been utilized to improve the poor survival chances of children with stage 4 neuroblastoma. This study reviews the risk profiles and the long-term outcome of patients from five consecutive German neuroblastoma trials. A total of 96% of all German patients registered at the German childhood cancer registry with neuroblastoma stage 4 over 1 year of age at diagnosis entered one of the trials during 1979-2001. Eight hundred and twenty-eight consecutive children were analyzed retrospectively. In spite of having significantly improved diagnostic tools like bone marrow superstaging and mIBG scintigraphy the stage 4 incidence did not increase after reaching completeness of the registry (5.4 cases/100,000 children at 1-14 years of age; P=0.52). The distribution of the primary tumors and of metastases was constant over the periods. The amount of bone marrow infiltration did not change with time. The risk factors lactate dehydrogenase, ferritin and MYCN, and the clinical risk groups 4A, 4B, 4C also remained constant over the trials with a few exceptions for NB97. The 5-year event free survival increased from 0.01+/-0.01 (NB79) to 0.14+/-0.03 (NB85), 0.16+/-0.04 (NB82), 0.27+/-0.02 (NB90), and 0.33+/-0.04 (NB97). The overall survival rates improved similarly from 0.04 (NB79) to 0.44 (NB97). In conclusion, the improved survival was associated with better treatment and not caused by lower risk profiles in stage 4 neuroblastoma patients.

Screening for renal cell carcinoma using ultrasonography: a feasibility study

OBJECTIVE

To assess the practicability and efficacy of systematic screening for renal cell carcinoma (RCC) by ultrasonography (US), as more small RCCs are being detected incidentally by US.

SUBJECTS AND METHODS

A 2-year screening programme for RCC was established for the general population (aged >or= 40 years) in two German cities, Mainz and Wuppertal. In cooperation with different health insurers, the organisers recruited general practitioners, internists and urologists in private practice who were experienced in and equipped to conduct renal US. The screening was offered in the form of cost-free renal US in the first year and a re-examination in the second. For any equivocal or positive renal mass, a reference ultrasonogram was provided by the urology departments at the two university hospitals.

RESULTS

In all, 9959 volunteers participated in the screening programme (49% men, 51% women, mean age 61 years, range 40-94) in the first year. Of these participants, 79% returned for re-examination in the second year. Thirteen (0.1%) subjects were found to have a renal mass, of which nine were RCC. The sensitivity of the programme was 82% (at the 1-year follow-up), and the predictive value 2% for equivocal findings on initial examination and 50% for positive findings. The incidence of other abnormal findings was 12%.

CONCLUSION

The screening programme was well accepted by physicians in private practice and by the eligible population. The method was effective, especially if equivocal findings were re-assessed by reference US before using further imaging studies, e.g. computed tomography or magnetic resonance imaging.

Second malignant neoplasms after treatment of childhood cancer

The aim of this study was to determine therapy-related risk factors for the development of second malignant neoplasm (SMN) after childhood cancer. The German Childhood Cancer Registry (GCCR) registers all childhood malignancies since 1980 including SMN. A nested case-control study with 238 SMN cases and 450 controls was conducted. A confirmatory, as well as an explorative, analysis was performed. Radiotherapy showed a small effect on the risk of SMN for doses >or=65 Gy. Regarding the chemotherapeutical agents, we saw increased Odds Ratios (OR) for high doses of cyclophosphamide (CP >8000 mg/m(2) OR=6.3 (95% Confidence Interval (CI): 1.3-30.2)), cisplatinum (DDP >435 mg/m(2) OR=2.8 (95% CI: 1.1-6.7)) and mercaptopurine (MP >5000 mg/m(2) OR=4.5 (95% CI: 1.1-18.9)). Patients jointly receiving high doses of MP (>5000 mg/m(2)) and dexamethasone (DEXA >or=1200 mg/m(2)) had an OR=6.9 (95% CI: 1.2-40.3). Our results could be added to those of other investigations to give indications for modifying future therapeutic strategies for childhood cancer.

[Ultrasound screening of renal cell carcinomas]

The increasing number of incidentally by ultrasound detected small renal cell carcinomas raises the question of the practicability and efficacy of a systematic screening for renal cell carcinoma by ultrasound. A two year screening program for renal cell carcinoma (RCC) was established for the general population (age > 40 years) in two cities, Mainz and Wuppertal. In cooperation with different health insurers, the organizers recruited general practitioners, internists and urologists in private practice who were experienced in and equipped for performing renal ultrasound. The screening was offered in the form of a cost free renal ultrasound in the first year and a re-examination in the second year. For any equivocal/positive renal mass, a reference ultrasound was provided the urology departments at the two university hospitals. 9959 volunteers participated in the screening program (49% male, 51% female) in the first year. The mean age was 61 (40-94) years. 79% of these participants returned for re-examination in the second year. Thirteen (0.1%) subjects were found to have a renal mass, of which nine were RCC. The sensitivity of the program was 82% (one year of follow-up). The predictive value was 2% for equivocal findings on initial exam and 50% for positive findings. The incidence of other abnormal findings was 12%. The screening program was well accepted by physicians in private practice and by the eligible population. The method proved effective, especially if equivocal findings were re-studied by reference sonography before further imaging studies such as CT and MRI were performed.

Risk factors for neuroblastoma at different stages of disease. Results from a population-based case-control study in Germany

Neuroblastoma is one of the childhood cancers included in two recent population-based case-control studies in West Germany. Altogether, 183 children under the age of 8 with neuroblastoma diagnosed in 1988-1994 and 1785 control children sampled from population registration files participated. Information on potential risk factors was obtained from the children's parents by a self-administered questionnaire and subsequent telephone interview. We observed positive associations with the use of oral contraceptives or other sex hormones during pregnancy (particularly with male offspring), a shorter gestational duration, lower birth weight, and maternal alcohol consumption during pregnancy. While the association with maternal use of oral contraceptives or sex hormones was strong for stages I/II (odds ratio 4.5, 95% confidence interval 1.2-16.5), the associations with shorter gestation duration (odds ratio 3.4, 95% confidence interval 1.7-6.7) as well as maternal alcohol consumption during pregnancy (>7 glasses/week odds ratio 5.2, 95% confidence interval 1.3-20.6) were observed only for the unfavourable advanced stages. It is notable that the associations in our study were either observed only for the advanced stages of disease or only for the less advanced stages, but not for both subgroups. This adds to evidence for the hypothesis that neuroblastoma consists of at least two distinct disease entities, which differ in clinical stage at the time of diagnosis.

Investigating regional differences in short-term effects of air pollution on daily mortality in the APHEA project: a sensitivity analysis for controlling long-term trends and seasonality

Short-term effects of air pollution on daily mortality in eight western and five central-eastern European countries have been reported previously, as part of the APHEA project. One intriguing finding was that the effects were lower in central-eastern European cities. The analysis used sinusoidal terms for seasonal control and polynomial terms for meteorologic variables, but this is a more rigid approach than the currently accepted method, which uses generalized additive models (GAM). We therefore reanalyzed the original data to examine the sensitivity of the results to the statistical model. The data were identical to those used in the earlier analyses. The outcome was the daily total number of deaths, and the pollutants analyzed were black smoke (BS) and sulfur dioxide (SO(2)). The analyses were restricted to days with pollutant concentration < 200 microg/m(3) and < 150 microg/m(3) alternately. We used Poisson regression in a GAM model, and combined individual city regression coefficients using fixed and random-effect models. An increase in BS by 50 microg/m(3) was associated with a 2.2% and 3.1% increase in mortality when analysis was restricted to days < 200 microg/m(3) and < 150 microg/m(3), respectively. The corresponding figures were 5.0% and 5.6% for a similar increase in SO(2). These estimates are larger than the ones published previously: by 69% for BS and 55% for SO(2). The increase occurred only in central-eastern European cities. The ratio of western to central-eastern cities for estimates was reduced to 1.3 for BS (previously 4.8) and 2.6 for SO(2) (previously 4.4). We conclude that part of the heterogeneity in the estimates of air pollution effects between western and central-eastern cities reported in previous publications was caused by the statistical approach used and the inclusion of days with pollutant levels above 150 microg/m(3). However, these results must be investigated further.

Survival of children with neuroblastoma. time trends and regional differences in Europe, 1978--1992

Neuroblastoma is one of the most common solid cancers in children. We present the data collected for the EUROCARE II study, describing survival patterns for children diagnosed in Europe 1985--1989 in detail, and exploring time trends from 1978 to 1992. On average, the mean 5-year survival rate was considerably higher in infants (79%) compared with older children (30--33%). The risk of death has dropped by 37% from 1978--1981 to 1990--1992. There is a pronounced difference between countries, with Scotland and England and Wales having two of the lowest survival rates (28% (95% confidence interval (CI) 14--48) and 36% (95% CI 31--41) 5-year survival rates, respectively). The survival rates in France, Germany and Italy (48--66% 5-year survival rate) were among the highest. This pattern corresponds to the incidence rates for these countries. It can be assumed that in neuroblastoma, both incidence and survival are related to the frequency of diagnosing asymptomatic cases with good prognosis among infants. However, one cannot ignore possible intercountry differences in the effectiveness of therapy.

Population-based and controlled study to evaluate neuroblastoma screening at one year of age in Germany: interim results

BACKGROUND

The German Neuroblastoma Screening Project is the first controlled and population-based screening study to evaluate the presumed benefit of neuroblastoma mass screening at 1 year of age (10-18 months).

PROCEDURE

Screening takes place in 6 of the 16 German states; children from the remainder serve as controls. The German Childhood Cancer Registry enables a mostly complete follow-up and detection of false-negative patients.

RESULTS

Up to December, 1999, 1,199,165 children were examined for urinary catecholamine metabolites and 124 cases of neuroblastoma were detected preclinically, giving a detection rate of 10.3/100,000. Within this cohort, 33 false-negative cases were found.

CONCLUSIONS

The results of this screening program will be crucial for further implementation of neuroblastoma screening.

Daily mortality and fine and ultrafine particles in Erfurt, Germany part I: role of particle number and particle mass

Increases in morbidity and mortality have been observed consistently and coherently in association with ambient air pollution. A number of studies on short-term effects have identified ambient particles as a major pollutant in urban air. This study, conducted in Erfurt, Germany, investigated the association of mortality not only with ambient particles but also with gaseous pollutants and indicators of sources. Part I of this study concentrates on particles. Data were collected prospectively over a 3.5-year period from September 1995 to December 1998. Death certificates were obtained from the local authorities and aggregated to daily time series of total counts and counts for subgroups. In addition to standard data for particle mass with diameters < or = 2.5 microm (PM2.5)* or < or = 10 microm (PM10) from impactors, a mobile aerosol spectrometer (MAS) was used to obtain size-specific number and mass concentration data in six size classes between 0.01 microm and 2.5 microm. Particles smaller than 0.1 microm were labeled ultrafine particles (three size classes), and particles between 0.1 and 2.5 microm were termed fine particles (three size classes). Concentrations of the gases sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) were also measured. The daily average total number concentration was 18,000 particles/cm3 with 88% of particles below 0.1 pm and 58% below 0.03 microm in diameter. The average mass concentration (PM2.5) was 26 microg/m3; of this, 75% of particles were between 0.1 and 0.5 microm in diameter. Other average concentrations were 38 microg/m3 for PM10, 17 microg/m3 for SO2, 36 microg/m3 for NO2, and 600 microg/m3 for CO. Ambient air pollution demonstrated a strong seasonality with maximum concentrations in winter. Across the study period, fine particle mass decreased, whereas ultrafine particle number was unchanged. The proportion of ultrafine particles below 0.03 microm diameter increased compared with the proportion of other particles. During the study, concentrations of SO2 and CO also decreased, whereas the concentration of NO2 remained unchanged. The data were analyzed using Poisson regression techniques with generalized additive modeling (GAM) to allow nonparametric adjustment for the confounders. Both the best single-day lag and the overall association of multiple days fitted by a polynomial distributed lag model were used to assess the lag structure between air pollution and death. Mortality increased in association with level of ambient air pollution after adjustment for season, influenza epidemics, day of week, and weather. In the sensitivity analyses, the results proved stable against changes of the confounder model. We saw comparable associations for ultrafine and fine particles in a distributed lag model where the contribution of the previous 4 to 5 days was considered. Furthermore, the data suggest a somewhat more delayed association of ultrafine particles than of fine particles if single-day lags are considered. The associations tended to be stronger in winter than in summer and at ages below 70 years compared to ages above 70 years. Analysis of the prevalent diseases mentioned on death certificates revealed that the overall association for respiratory diseases was slightly stronger than for cardiovascular diseases. In two-pollutant models, associations of ultrafine and fine particles seemed to be largely independent of each other, and the risk was enhanced if both were considered at the same time. Furthermore, when the associations were summed for the six size classes between 0.01 and 2.5 microm, the overall association was clearly stronger than the associations of the individual size classes alone. Associations were observed for SO2, NO2, and CO with mortality despite low concentrations of these gases. These associations disappeared in two-pollutant models for NO2 and CO, but they remained stable for SO2. The persistence of the SO2 effect was interpreted as artifact, however, because the SO2 concentration was much below levels at which effects are usually expected. Furthermore, the results for SO2 were inconsistent with those from earlier studies conducted in Erfurt. We conclude that both fine particles (represented by particle mass) and ultrafine particles (represented by particle number) showed independent effects on mortality at ambient concentrations. Comparable associations for gaseous pollutants were interpreted as artifacts of collinearity with particles from the same sources.

Nephron-sparing surgery of renal cell carcinoma with a normal opposite kidney: long-term outcome in 180 patients

OBJECTIVES

To investigate the long-term outcome of an organ-saving approach for renal cell carcinoma (RCC) with a normal opposite kidney (elective indication).

METHODS

Since 1979, 180 patients have undergone nephron-sparing surgery at our institution for RCC in the presence of a normal contralateral kidney. The mean age was 56 years (range 23 to 83), and the mean follow-up was 4.7 years (maximum 14. 8). Most of these tumors were found incidentally, with a mean tumor diameter on ultrasound of 3.3 cm (range 1.0 to 8.6).

RESULTS

The postoperative course was unremarkable in 173 patients. Postoperative bleeding was encountered in 4 patients and urinary extravasation in an additional 3 patients. No surgical reintervention was necessary. One hundred seventy-five RCCs were pT1 and 5 were pT3a; 73 were grade 1, 100 grade 2, and 7 were grade 3. The mean tumor diameter (surgical specimen) was 3.2 cm (range 0.5 to 7). In 132 cases, the tumor was less than 4 cm and in 48 cases, greater than 4 cm. Three patients experienced local tumor recurrence (1.6%) during follow-up, and two others developed distant metastases. The 5-year tumor-specific survival rate was 98.0%.

CONCLUSIONS

Nephron-sparing surgery for RCC under an elective indication in selected patients offers excellent long-term survival and an acceptably low local tumor recurrence rate. These results support the concept of nephron-sparing surgery in the presence of a normal contralateral kidney.

Associations between mortality and air pollution in central Europe

Increased mortality has been observed in association with elevated concentrations of air pollutants in European cities and in the United States. We reassessed the effects of particulate matter in Central Europe. Mortality and air pollution data were obtained for a highly polluted region of the Czech Republic and a rural region in Germany. Poisson regression analyses were conducted considering trend, season, meteorology, and influenza epidemics as confounders in both a parametric and a nonparametric approach. The Czech Republic had a 3.8% increase in mortality [95% confidence interval (CI), 0.8-6.9%] in association with 100 microg/m(3) total suspended particles (TSP) (lagged 2 days) for the time period 1982-1994. During the last 2 years of study, 68% of the TSP consisted of particulate matter [less than/equal to] 10 microm in aerodynamic diameter (PM(10)). An increase of 100 microg/m(3) TSP (lagged 1 day) was associated with a 9.5% increase in mortality (CI, 1.2-18.5%) and 100 microg/m(3) PM(10 )(lagged 1 day) showed a 9.8% increase in mortality (CI, 0.7-19.7%). We found no evidence for an association between mortality and particulate matter in the rural area in Germany at the Czech border. Data from the coal basin in the Czech Republic suggested an increase in mortality associated with the concentration of particulate matter in a highly polluted setting in Central Europe that is consistent with the associations observed in other western European cities and in the United States.

[Pilot study on early diagnosis of renal cell carcinoma by sonography]

The goal of this study was to investigate the practicability and effectiveness of a systematic screening for renal cell carcinoma by ultrasound in the course of the established German Health Ministry screening programs.

METHODS

In two centers (Mainz and Wuppertal) a screening program for renal cell carcinoma for all citizens (age > 40 years) was established. The screening was divided into two phases (time period 1 year): (1) All citizens over 40 years could attend voluntarily a cost-free ultrasound investigation. (2) A follow-up investigation for the entire screening population was provided.

RESULTS

Ten thousand volunteers attended the screening program. Mean age was 60 years. Thirteen renal cell carcinomas were detected. The incidence of other findings was 15%; none of those required further treatment.

CONCLUSION

Systematic screening for renal cell carcinoma by ultrasound is cost-effective and showed high acceptance and practicability in a German population. The rate of detection of renal cell carcinoma was higher than initially statistically calculated.

Time-series analysis of air pollution and cause-specific mortality

Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality. We used Poisson autoregressive models that controlled for trend, season, influenza epidemics, and meteorologic influences to assess the short-term effects of air pollution at each city. We then compared and pooled the city-specific results in a meta-analysis. The pooled relative risks of daily deaths from cardiovascular conditions were 1.02 [95% confidence interval (CI) = 1.01-1.04] for a 50 microg/m3 increment in the concentration of black smoke and 1.04 (95% CI = 1.01-1.06) for an increase in sulfur dioxide levels in western European cities. For respiratory diseases, these figures were 1.04 (95% CI = 1.02-1.07) and 1.05 (95% CI = 1.03-1.07), respectively. These associations were not found in the five central European cities. Eight-hour averages of ozone were also moderately associated with daily mortality in western European cities (relative risk = 1.02; 95% CI = 1.00-1.03 for cardiovascular conditions and relative risk = 1.06; 95% CI = 1.02-1.10 for respiratory conditions). Nitrogen dioxide did not show consistent relations with daily mortality. These results are similar to previously published data and add credence to the causal interpretation of these associations at levels of air pollution close to or lower than current European standards.

Short-term effects of air pollution on hospital admissions of respiratory diseases in Europe: a quantitative summary of APHEA study results. Air Pollution and Health: a European Approach

The Air Pollution and Health: a European Approach (APHEA) project is a coordinated study of the short-term effects of air pollution on mortality and hospital admissions. Five West European cities (i.e., London, Amsterdam, Rotterdam, Paris, Milano) contributed several years of hospital admissions data for all respiratory causes. In the current study, the authors describe the results obtained from the quantitative pooling (meta-analysis) of local analyses. The diagnostic group was defined by ICD 460-519. The age groups studied were 15-64 y (i.e., adults) and 65+ y (elderly). The air pollutants studied were sulfur dioxide; particles (i.e., Black Smoke or total suspended particles); ozone; and nitrogen dioxide. The pollutants were obtained from existing fixed-site monitors in a standardized manner. We used Poisson models and standardized confounder models to examine the associations between daily hospital admissions and air pollution. We conducted quantitative pooling by calculating the weighted means of local regression coefficients. We used a fixed-effects model when no heterogeneity could be detected; otherwise, we used a random-effects model. When possible, the authors investigated the factors correlated with heterogeneity. The most consistent and strong finding was a significant increase of daily admissions for respiratory diseases (adults and elderly) with elevated levels of ozone. This finding was stronger in the elderly, had a rather immediate effect (same or next day), and was homogeneous over cities. The elderly were affected more during the warm season. The Sulfur dioxide daily mean was available in all cities, and it was not associated consistently with an adverse effect. Effects were present in areas in which more than one station was used in the assessment of daily exposure. Some significant associations were observed, although no conclusion that related to an overall particle effect could be drawn. The effect of Black Smoke was significantly stronger with high nitrogen dioxide levels on the same day, but nitrogen dioxide itself was not associated with admissions. The ozone results were in good agreement with the results of similar U.S. studies. The coherence of the results of this study and other results gained under different conditions strengthens the argument for causality.

Urban air pollution and emergency admissions for asthma in four European cities: the APHEA Project

BACKGROUND

A study was undertaken to assess the combined association between urban air pollution and emergency admissions for asthma during the years 1986-92 in Barcelona, Helsinki, Paris and London.

METHODS

Daily counts were made of asthma admissions and visits to the emergency room in adults (age range 15-64 years) and children (< 15 years). Covariates were short term fluctuations in temperature and humidity, viral epidemics, day of the week effects, and seasonal and secular trends. Estimates from all the cities were obtained for the entire period and separately by warm or cold seasons using Poisson time-series regression models. Combined associations were estimated using meta-analysis techniques.

RESULTS

Daily admissions for asthma in adults increased significantly with increasing ambient levels of nitrogen dioxide (NO2) (relative risk (RR) per 50 micrograms/m3 increase 1.029, 95% CI 1.003 to 1.055) and non-significantly with particles measured as black smoke (RR 1.021, 95% CI 0.985 to 1.059). The association between asthma admissions and ozone (O3) was heterogeneous among cities. In children, daily admissions increased significantly with sulphur dioxide (SO2) (RR 1.075, 95% CI 1.026 to 1.126) and non-significantly with black smoke (RR 1.030, 95% CI 0.979 to 1.084) and NO2, though the latter only in cold seasons (RR 1.080, 95% CI 1.025 to 1.140). No association was observed for O3. The associations between asthma admissions and NO2 in adults and SO2 in children were independent of black smoke.

CONCLUSIONS

The evidence of an association between air pollution at current urban levels and emergency room visits for asthma has been extended to Europe. In addition to particles, NO2 and SO2--by themselves or as a constituent of a pollution mixture--may be important in asthma exacerbations in European cities.

Short-term effects of ambient oxidant exposure on mortality: a combined analysis within the APHEA project. Air Pollution and Health: a European Approach

The Air Pollution and Health: a European Approach (APHEA) project is a coordinated study of the short-term effects of air pollution on mortality and hospital admissions using data from 15 European cities, with a wide range of geographic, sociodemographic, climatic, and air quality patterns. The objective of this paper is to summarize the results of the short-term effects of ambient oxidants on daily deaths from all causes (excluding accidents). Within the APHEA project, six cities spanning Central and Western Europe provided data on daily deaths and NO2 and/or O3 levels. The data were analyzed by each center separately following a standardized methodology to ensure comparability of results. Poisson autoregressive models allowing for overdispersion were fitted. Fixed effects models were used to pool the individual regression coefficients when there was no evidence of heterogeneity among the cities and random effects models otherwise. Factors possibly correlated with heterogeneity were also investigated. Significant positive associations were found between daily deaths and both NO2 and O3. Increases of 50 micrograms/m3 in NO2 (1-hour maximum) or O3 (1-hour maximum) were associated with a 1.3% (95% confidence interval 0.9-1.8) and 2.9% (95% confidence interval 1.0-4.9) increase in the daily number of deaths, respectively. Stratified analysis of NO2 effects by low and high levels of black smoke or O3 showed no significant evidence for an interaction within each city. However, there was a tendency for larger effects of NO2 in cities with higher levels of black smoke. The pooled estimate for the O3 effect was only slightly reduced, whereas the one for NO2 was almost halved (although it remained significant) when two pollutant models including black smoke were applied. The internal validity (consistency across cities) as well as the external validity (similarities with other published studies) of our results on the O3 effect support the hypothesis of a causal relation between O3 and all cause daily mortality. However, the short-term effects of NO2 on mortality may be confounded by other vehicle-derived pollutants. Thus, the issue of independent NO2 effects requires additional investigation.

Short-term effects of ambient sulphur dioxide and particulate matter on mortality in 12 European cities: results from time series data from the APHEA project. Air Pollution and Health: a European Approach

OBJECTIVES

To carry out a prospective combined quantitative analysis of the associations between all cause mortality and ambient particulate matter and sulphur dioxide.

DESIGN

Analysis of time series data on daily number of deaths from all causes and concentrations of sulphur dioxide and particulate matter (measured as black smoke or particles smaller than 10 microns in diameter (PM10)) and potential confounders.

SETTING

12 European cities in the APHEA project (Air Pollution and Health: a European Approach).

MAIN OUTCOME MEASURE

Relative risk of death.

RESULTS

In western European cities it was found that an increase of 50 micrograms/m3 in sulphur dioxide or black smoke was associated with a 3% (95% confidence interval 2% to 4%) increase in daily mortality and the corresponding figure for PM10 was 2% (1% to 3%). In central eastern European cities the increase in mortality associated with a 50 micrograms/m3 change in sulphur dioxide was 0.8% (-0.1% to 2.4%) and in black smoke 0.6% (0.1% to 1.1%). Cumulative effects of prolonged (two to four days) exposure to air pollutants resulted in estimates comparable with the one day effects. The effects of both pollutants were stronger during the summer and were mutually independent.

CONCLUSIONS

The internal consistency of the results in western European cities with wide differences in climate and environmental conditions suggest that these associations may be causal. The long term health impact of these effects is uncertain, but today's relatively low levels of sulphur dioxide and particles still have detectable short term effects on health and further reductions in air pollution are advisable.

Air pollution and daily admissions for chronic obstructive pulmonary disease in 6 European cities: results from the APHEA project

We investigated the short-term effects of air pollution on hospital admissions for chronic obstructive pulmonary disease (COPD) in Europe. As part of a European project (Air Pollution and Health, a European Approach (APHEA)), we analysed data from the cities of Amsterdam, Barcelona, London, Milan, Paris and Rotterdam, using a standardized approach to data eligibility and statistical analysis. Relative risks for daily COPD admissions were obtained using Poisson regression, controlling for: seasonal and other cycles; influenza epidemics; day of the week; temperature; humidity and autocorrelation. Summary effects for each pollutant were estimated as the mean of each city's regression coefficients weighted by the inverse of the variance, allowing for additional between-cities variance, as necessary. For all ages, the relative risks (95% confidence limits (95% CL)) for a 50 microg x m(-3) increase in daily mean level of pollutant (lagged 1-3 days) were (95% CL): sulphur dioxide 1.02 (0.98, 1.06); black smoke 1.04 (1.01, 1.06); total suspended particulates 1.02 (1.00, 1.05), nitrogen dioxide 1.02 (1.00, 1.05) and ozone (8 h) 1.04 (1.02, 1.07). The results confirm that air pollution is associated with daily admissions for chronic obstructive pulmonary disease in European cities with widely varying climates. The results for particles and ozone are broadly consistent with those from North America, though the coefficients for particles are substantially smaller. Overall, the evidence points to a causal relationship but the mechanisms of action, exposure response relationships and pollutant interactions remain unclear.