Cancer mortality in Ireland, 1926-1995.

BACKGROUND: Investigation of long time series of cancer data can still be very useful in helping to identify Cancer Control priorities and achievements. Since the partition of Ireland into the independent Republic of Ireland and Northern Ireland, which remained part of the United Kingdom, cancer mortality data have been published in an essentially similar format in both countries. The information presented here will contribute to providing a basis for the collaborative Cancer Research programme initiated recently. PATIENTS AND METHODS: Cancer mortality data have been assembled and analysed separately for the Republic of Ireland and Northern Ireland: the data have then been combined to present mortality rates for the whole of Ireland, covering the period from 1926 to 1995. Several rubrics had to be aggregated to provide data continuously over the time span (e.g. colon and rectum and cervix and body of the uterus). When data were only available in 10-year classes of age, the EM algorithm was employed to obtain 5-year age-specific rates. All rates presented are age-standardised, employing the World Standard Population. RESULTS: In women, the death rate from all neoplasms combined increased very slightly from 117 per 100 000 in 1946-1950 to 120 per 100 000 in 1991-1995. In men, the death rate increased from 127 per 100 000 to 172 per 100 000 over the same time period. The overall cancer death rate in Ireland is currently similar to the European average in men, although in women it is among the top fifth of national cancer mortality rates in European countries. While cancer is a major cause of death in Ireland, there is no evidence of an evolving epidemic building up: the death rates from most forms of cancer are declining towards the end of the time period considered. CONCLUSIONS: As demonstrated by falling death rates from Hodgkin's disease and testicular cancer, major treatment advances appear to have been incorporated effectively into clinical practice in Ireland. Progress is apparent in tobacco control and further initiatives in this area must be undertaken since tobacco appears to be the only major new carcinogen introduced recently into the Irish environment during the period covered by this study. Effective population-based screening programmes for cervix and breast cancer and, more controversially, consideration of a National Prostate Cancer Screening programme, offer scope for further improvement in mortality. Examination of this long time series of mortality data from Ireland provides information about the evolving cancer pattern and provides the necessary background to evaluate the impact of the cross-border cancer research activities now being launched.