Georges Schüler

Die Epidemiologie der colorectalen Krebse — international und in der Schweiz

SummaryThe descriptive epidemiology of colorectal cancer in Switzerland is presented and compared to international geographic patterns and time trends. Switzerland has a typical western pattern of relatively high incidence and mortality rates. Mortality from colon cancer is stable with a slight male preponderance; rectal cancer mortality is decreasing, especially in females. The proportion of rectal cancers in the incidence data of colorectal cancer is not as prominent as shown by French or German cancer registries. There is an urban-ruralgradient, more prominent in colon than in rectal cancer. As in other countries, white collar occupations show elevated PMRs and manual occupations low ones, a finding which is confounded with the geographical distribution of these occupations.The descriptive epidemiology of colorectal cancer in Switzerland is presented and compared to international geographic patterns and time trends. Switzerland has a typical western pattern of relatively high incidence and mortality rates. Mortality from colon cancer is stable with a slight male preponderance; rectal cancer mortality is decreasing, especially in females. The proportion of rectal cancers in the incidence data of colorectal cancer is not as prominent as shown by French or German cancer registries. There is an urban-rural-gradient, more prominent in colon than in rectal cancer. As in other countries, white collar occupations show elevated PMRs and manual occupations low ones, a finding which is confounded with the geographical distribution of these occupations.

Exploration of interactions between prognostic factors of stage I malignant melanoma

While many studies have sought prognostic factors of malignant melanoma using multivariate survival models, the interaction between predictors has been much less studied. We have studied data from 1,560 patients with stage I melanoma collected at the Cancer Registry of the Canton of Zurich over the period 1980–1990 and explored interactions between predictors by identifying two separate multivariate Cox models for men and women and investigating two-way interactions between predictors in each model. Considerable differences between models for men and women were observed. In particular, in women a pronounced interaction between ‘histology’ and ‘Clark level’ was identified. Without this interaction ‘histology’ and ‘Clark level’ are not significant but when the interaction term was included both predictors become significant. Thus, omission of an interaction term may preclude the recognition of main effects (‘masking’). For female patients with nodular tumours prognosis is essentially independent of Clark level. In contrast, for female patients with non-nodular tumours, prognosis was found to be strongly dependent on Clark level. In the case of Clark level 2 prognosis was extremely good: no patient was observed to die from melanoma. We conclude that it may be worth considering interaction terms. With large enough sample sizes it may be preferable to stratify patients into subgroups and to identify separate models for each stratum instead of having to cope with interactions of higher order.

Too little concern for breast cancer risk in radiation protection estimates

Risk estimates of radiogenic breast cancer from recent consensus reports are found to depend as much on the models used as on the data. Some features of the models of BEIR V and the ICRP 1990 Recommendations are hardly supported in the literature and tend to underrate breast cancer risk in radioprotection.

Überblick aus präventiver Sicht

Nach der geographischen Detaillierung, die fur jede Region die in der Todesursachenstatistik enthaltene Information uber ihre Gesundheitsprobleme aufbereitet hat, scheint es im Sinn einer Synthese angezeigt, nach Regionen mit ahnlicher Konstellation und somit ahnlichen Ansatzmoglichkeiten fur die Pravention zu suchen. Es ist klar, dass damit nur der Teil der Gesundheitsprobleme erfasst ist, der aus der Mortalitat, genauer gesagt aus ihren regionalen Unterschieden abgeleitet werden kann. Doch die Todesursachenstatistik bleibt uber weite Bereiche die einzige Quelle fur kleinraumige, uber das ganze Land vergleichbare Informationen uber den Gesundheitszustand der Bevolkerung. Daher ist es von Interesse, benachbarte Gebiete mit ahnlichen Gesundheitsproblemen herauszustellen: von dieser Grundlage aus kann man eine uberregionale Zusammenarbeit in der Pravention anzielen, die den regionalen Gegebenheiten besser Rechnung tragt.

Charakteristika und Gesundheitsprobleme der Regionen

370′000 Einwohner (1980). Die MS-Region Zurich umfasst im Gegensatz zu den anderen Grossstadtregionen keine Vorortsgemeinden; bis in die 80er Jahre bevolkerungsreichste der 106 Regionen; Abnahme um 14% von 1970 bis 1990 (starker war die Abnahme nur in den Jura-Regionen La Vallee und La Chaux-de-Fonds sowie in Basel-Stadt); hochste Bevolkerungsdichte nach Basel-Stadt.

Luftverschmutzung und Lungenkrebs

: This review on air pollution and lung cancer recapitulates the main issues in this field (urban-rural-gradients; experimental data and occupational epidemiology of exposure to PAH; smoking and occupation as confounders). Definite risk increases have been observed in the vicinity of point emission sources. Within Switzerland lung cancer shows an urban/rural gradient in both sexes. The geographical distribution of the male cases can hardly be explained only by the patterns of smoking alone.