Urban-rural differences in cancer incidence in The Netherlands 1989-1991.

BACKGROUND

Differences in cancer incidence have been observed between urban and rural communities for many decades. These differences have been attributed for the most part to lifestyle aspects. In Western populations, however, differences in lifestyle have diminished. This study addressed the question: For which cancer sites can differences in cancer occurrence still be demonstrated between urban and rural communities in the Netherlands?

METHODS

Cancer incidence data from 1989 to 1991 inclusive, were obtained from the Netherlands Cancer Registry. Age-adjusted, site-specific incidence rates were calculated for five classes of municipalities classified by address density.

RESULTS

With increasing urbanization, slightly higher incidence rates were observed for all cancer sites combined (rate ratio [RR] = 1.08 in males and 1.12 in females). Statistically significant RR of > 1.4 were observed for Kaposi's sarcoma (m), mesothelioma (m), cancer of the liver (m), mouth/pharynx (m + f), oesophagus (f), larynx (f), lung (f), other respiratory organs (f), cervix (f) and Hodgkin's disease (m). Significantly lower incidence rates were found in urban areas for non-melanoma skin (m + f) and lip cancer (m).

CONCLUSIONS

In males, the urban excess of tobacco-related cancer has largely disappeared. However, urban-rural differences in cancer incidence still exist for other cancer sites and for tobacco-related cancer in females. Apparently, differences in the prevalence of lifestyle factors are still large enough to cause variation in cancer incidence.