gms | German Medical Science

49. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds)
19. Jahrestagung der Schweizerischen Gesellschaft für Medizinische Informatik (SGMI)
Jahrestagung 2004 des Arbeitskreises Medizinische Informatik (ÖAKMI)

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie
Schweizerische Gesellschaft für Medizinische Informatik (SGMI)

26. bis 30.09.2004, Innsbruck/Tirol

Incidence of Uveal Melanoma in Northrhine-Westphalia, Germany: Application of a hybride case-control design (RIFA Study)

Meeting Abstract (gmds2004)

  • corresponding author presenting/speaker Andreas Stang - Institute for Medical Informatics, Biometry and Epidemiology, Medical Faculty, University of Duisburg-Essen, Essen, Deutschland
  • Andrea Schmidt-Pokrzywniak - Institute for Medical Informatics, Biometry and Epidemiology, Medical Faculty, University of Duisburg-Essen, Essen, Deutschland
  • Norbert Bornfeld - Division of Ophthalmology, Medical Faculty, University of Duisburg-Essen, Essen, Deutschland
  • Christa Stegmaier - Saarland Cancer Registry, Saarbrücken, Deutschland
  • Karl-Heinz Jöckel - Institute for Medical Informatics, Biometry and Epidemiology, University of Duisburg-Essen, Essen, Deutschland

Kooperative Versorgung - Vernetzte Forschung - Ubiquitäre Information. 49. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds), 19. Jahrestagung der Schweizerischen Gesellschaft für Medizinische Informatik (SGMI) und Jahrestagung 2004 des Arbeitskreises Medizinische Informatik (ÖAKMI) der Österreichischen Computer Gesellschaft (OCG) und der Österreichischen Gesellschaft für Biomedizinische Technik (ÖGBMT). Innsbruck, 26.-30.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04gmds147

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/gmds2004/04gmds147.shtml

Published: September 14, 2004

© 2004 Stang et al.
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Outline

Text

Introduction

Uveal melanoma of the eye is the most common primary intraocular malignancy in adults with an incidence rate of up to 1.0 per 100,000 person years (age-standardized, world standard) in Europe. With the gradual introduction of eye-preserving therapies for uveal melanoma starting in the 1970s, the proportion of uveal melanoma that were treated by enucleation and were histologically verified decreased over the decades [1]. Cancer registries that heavily rely on reports from pathologists may underdetect uveal melanoma over time.

In our ongoing case-control study on risk factors of uveal melanoma (RIFA study) [2], we used a hybride case-control study design [3] that also enables us to estimate quasi population-based incidence rates of uveal melanoma in Northrhine-Westphalia (NRW), and the Ruhrarea that is virtually not covered by a population-based cancer registry. Here we report incidence rates of uveal melanoma of the Ruhrarea and compare these rates with the Saarland Cancer Registry.

Methods

RIFA Study

Within the ongoing RIFA case-control study on the etiology of uveal melanoma, we registered all patients treated at the referral center for uveal melanoma, Division of Ophthalmology, University of Duisburg-Essen, Germany, which treats about 400-500 uveal melanoma patients annually. We regard the case ascertainment as a quasi population-based case ascertainment for the Ruhrarea due to the referral center effect. The case-control study that includes patients living all over Germany until now registered 363 cases (period: Oct 1st, 2002-Feb 29th, 2004). Patients who fulfilled the following criteria were included in the incidence study: (1) first diagnosis of uveal melanoma between October 1, 2002 and February 29, 2004, (2) age at diagnosis: 20-74 years, (3) living in NRW, and (4) being treated for uveal melanoma. Overall, 148 cases fulfilled the inclusion criteria. According to the study protocol of the case-control study, n=7 cases were not eligible (n=1: moved away; n=6: no sufficient command of the German language) but were included in the incidence study because population-based cancer registries would also include those cases.

Saarland Cancer Registry

We extracted eye tumor cases aged 20-74 years, diagnosed 1997 through 2001 from the Saarland Cancer Registry file. After exclusion of eye tumors of histology other than melanoma, 31 cases remained in the data set. Of these, 4 cases had no information on histology and maybe uveal melanoma.

Statistical Methods

We calculated age-truncated (20-74 years), crude ("rate") and age-standardized (World Standard Population) incidence rate ("ASR") (cases per million) and standard errors ("SE") of the ASRs of the Saarland and NRW. To assess the effect of potential case catchment, we also estimated ASRs based on the population of the Ruhrarea, an industrialized urban area within NRW, and of the population of the inner circle of the Ruhrarea including Essen, Bottrop, Mülheim, Duisburg, Oberhausen, Gelsenkirchen, Herne, Bochum and Dortmund (inner Ruhrarea). We ran a sensitivity analysis by excluding the four cases with unknown histology from the cancer registry file.

Results

During the 17-month period, the RIFA study registered 148 cases from NRW. The Saarland Cancer Registry detected 31 cases during a 5-year calendar period. The crude and age-standardized incidence rates of uveal melanoma are presented in table 1 [Tab. 1]. The age-truncated, age-standardized incidence rates were very similar in NRW and Saarland. However, the proportion of clinically diagnosed uveal melanoma treated by eye-preserving therapies differed. Only one case (3%) of the Saarland Registry was clinically diagnosed. This proportion was 76% in the RIFA study.

Although based on small numbers, about 10% (15 cases) of the RIFA study cases were younger than 45 years whereas no case of the Saarland Cancer Registry was younger than 45 years.

Discussion

Incidence rates of the NRW study region of the RIFA study were very similar to the rates of the Saarland Cancer Registry. However, the proportion of morphologically verified uveal melanoma differed greatly and most likely is a registration artefact among both, the Saarland Cancer Registry and the RIFA study. The Saarland Cancer Registry heavily relies on pathology reports and therefore suffers from underdetection of clinically diagnosed uveal melanoma. The RIFA study may underdetect uveal melanoma that are treated by enucleation that can be performed in every general hospital whereas eye-preserving therapies are usually performed in eye tumor centers.

The former population-based EVA case-control study [4] that we conducted from 1995 through 1998 in Hamburg, Bremen, Saarland and Essen contained 37 uveal melanoma cases. Of these, 54% were clinically diagnosed which supports the view that clinically diagnosed uveal melanoma are underdetected in the Saarland.

Acknowledgment

Sponsored by Deutsche Forschungsgemeinschaft (DFG), Förderkennzeichen KFO 109/1-1 and Bundesamt für Strahlenschutz (BfS), Förderkennzeichen: M8811


References

1.
Stang A, Jöckel KH. Trends in the incidence of ocular melanoma in the United States, 1974-1998 (letter). Cancer Causes Control 2004;15:95-96
2.
Schmidt-Pokrzywniak A, Jöckel KH, Stang A. Assessment of phenotypical characteristics for melanoma research. Preliminary results of the RIFA study. Biometrical J 2004;46(suppl):106
3.
Stang A, Jöckel KH. Appending epidemiological studies to conventional case-control studies (hybride case-control studies). Eur J Epidemiol 2004 (in press)
4.
Stang A, Anastassiou G, Ahrens W, Bromen K, Bornfeld N, Jöckel KH. The possible role of radio-frequency radiation in the development of uveal melanoma. Epidemiology 2001;12:7-12