Cancer mortality in Ireland, 1926–1995

P. Boyle1,+, S. Golia1, P. Daly2, P. G. Johnston3 and C. Robertson1

1 Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy; 2 Department of Medical Oncology, St James’ Hospital, Dublin, Republic of Ireland; 3 Department of Oncology, The Queen’s University of Belfast, Belfast City Hospital, Belfast, UK

Received 5 December 2001; revised 19 April 2002; accepted 22 July 2002


    Abstract
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
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.

Key words: cancer, control, epidemiology, Ireland


    Introduction
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Investigation of long time series of cancer data can still be very useful in helping to identify cancer patterns that give insight into underlying changes in the impact of cancer risk factors or on treatment, or both. There are several parts of the world where cancer mortality data have been collected and published for very long periods of time. 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. This provides an additional advantage in examining the temporal evolution of cancer in two neighbouring countries where lifestyle is remarkably similar but where significant social differences have existed with a strong industrial base in Northern Ireland and the Republic of Ireland mainly having an agricultural economy. Although both countries have relatively small populations, examination of the rates in both countries and then creating a composite rate for Ireland (in the absence of any great differences in the rates) can lead to the calculation of a more stable cancer rate than could otherwise be available.

Michael Alderson and Robert Case put together Serial Mortality Tables separately for the Republic of Ireland [1] and Northern Ireland [2] using mortality and population data available since partition in the mid-1920s. There are some inconsistencies in how the data have been collected and presented, particularly with the use of different age classes at different time periods. However, there are statistical tools which are useful in removing some of these obstacles. In addition to this historical series, mortality data are available until the mid-1990s from the World Health Organisation (WHO) Mortality Database.

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. The United States National Cancer Institute has recently embarked on an international partnership with the developing cancer programmes in the Republic of Ireland and in Northern Ireland in an attempt to further improve the quality and range of cancer services available for patients. The All Ireland–NCI Cancer Consortium held its first conference in Belfast in October 1999 when the aims of the agreement were presented [3]. The information presented here will contribute to providing a basis for prioritising and evaluating the collaborative cancer research programme initiated as an outcome of the peace process.


    Patients and methods
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
The databases employed for the Republic of Ireland and Northern Ireland have been constructed using the Serial Mortality Tables generated by the Institute of Cancer Research (London) until 1970 and subsequently from the WHO Mortality Database. The final data cover the period from 1926 to 1995 for the Republic of Ireland and from 1926 to 1997 for Northern Ireland: 1995 and 1997 are, respectively, the latest years for which mortality data are available for both countries. The data are grouped by 5-year time period groups and 5-year age groups.

There are some inconsistencies in how the data are presented which need to be allowed for prior to calculating the death rates. In the tables of the Republic of Ireland, data are presented for the age group 76–85 for the periods 1926–1930, 1931–1935, 1936–1940, 1941–1945 and 1946–1950. For consistency with later data, data are required for the age groups 76–80 and 81–85. Disaggregation has been achieved using a non-parametric cubic spline [4] applied to the cumulative population.

In the mortality data for both the Republic of Ireland and Northern Ireland for the period from 1926 to 1950, there are many grouped age classes. In order to disaggregate these classes, the EM algorithm [5, 6] was employed, based on an age-period Poisson regression model. For example, data for 1926–1950 may be available in age classes 41–50, while data from 1950 onwards are available in 5-year age groups. Also, combined data for age groups 76–85 are presented in the Republic of Ireland from 1926 to 1950. This disaggregation was only necessary for the analysis of age-specific rates and not for the calculation of the age-standardised rates.

Separately for each site and gender, the first estimate of the number of cases in each 5-year age class was obtained by dividing the total number of deaths in the aggregated class by the number of 5-year age groups within it. Usually there were only two which meant assigning half the deaths to each age class. An age-period model was then fitted using all the data in the 5-year groups. This gives the predicted number of deaths in each age group (eij). The number of deaths in the 5-year age groups of the aggregated age classes is then re-estimated in proportion to the predicted number of deaths. If there are two 5-year age groups aggregated with predicted values e1 and e2 and total deaths (d) in the aggregated group, then e1/(e1 + e2)*d and e2/(e1 + e2)*d are used as the new estimates of the numbers of deaths. This process is then repeated until the estimated deaths converge.

Due to changes in coding practice and publishing strategy, the data for oral cavity and larynx cancer are unavailable for the period from 1951 to 1955. In this event, we have taken the average of the preceding and following rates for the periods for men and women in this time period to get an estimate of the rate.

In order to minimise the effect of differences in age composition in different periods and areas, the rates are age-adjusted to the World Standard Population [7]. The relative risk of a particular cancer in Northern Ireland compared with the Republic of Ireland was calculated by the ratio of the two age-adjusted rates, for men and women separately. The 95% confidence interval for the ratios was calculated using the variance of the ratio [8] and a normal approximation [8].


    Results
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
The relative risks of cancer in the Republic of Ireland relative to Northern Ireland have generally been around 1 with a confidence interval covering this value (Tables 1, 2, 3 and 4). For most forms of cancer, the mortality rate among men has been consistently moderately higher in Northern Ireland than in the Republic of Ireland: for some sites such as lung and pleura, intestines and bladder the excess has been consistently statistically significant. In all cases, the temporal patterns have been very similar (data not presented). A similar situation exists in women. There is no compelling reason to suggest that the rates, and the trends in the rates, for any form of cancer are radically different between the two regions and so the combined rate for Ireland is calculated for all sites and gender combinations. For some cancer sites, there have been changes in the recording practices during the time period covered by this study: these will be discussed in each cancer site considered.


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Table 1. Relative risk of cancer mortality in Northern Ireland compared with the Irish Republic in men, 1926–1995
 

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Table 2. Relative risk of cancer mortality in Northern Ireland compared with the Irish Republic in men, 1926–1995
 

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Table 3. Relative risk of cancer mortality in Northern Ireland compared with the Irish Republic in women, 1926–1995
 

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Table 4. Relative risk of cancer mortality in Northern Ireland compared with the Irish Republic in women, 1926–1995
 
Cancer of the oral cavity
The oral cavity data set is obtained by adding together the deaths for cancer of lip, tongue, mouth, tonsils and pharynx. For the time period 1951–1955, data for mouth, tonsils and pharynx cancer are not available: the rate has been estimated by the average of the rates in the time periods before and after. In addition, there is no complete information for the time period 1946–1950 regarding cancer of the mouth, tonsils and pharynx; the available data cover the period 1946–1949. These data are multiplied by 5/4 in order to approximate the true number of deaths in the period 1946–1950. The mortality rate has remained higher in men than in women (Figure 1) throughout the time period considered. In men there has been a considerable decline from 11.4 per 100 000 in the period 1926–1930 to 4.2 per 100 000 in the last period considered, 1991–1995 (Figure 1). In women there has been a decline also with the rates falling from around 2.0 per 100 000 until the latter half of the 1960s when the rates started to decline to around 1.0 per 100 000, in 1991–1995 (Figure 1).



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Figure 1. Oral, laryngeal and oesophageal cancer rates in Ireland in (A) women and (B) men. Annual, average age-standardised death rates per 100 000, 1926–1995.

 
Cancer of the larynx
The data on cancer of the larynx in Northern Ireland for the time period 1951–1955 are not available. Moreover, there is no complete information for the time period 1946–1950; the available data cover the period 1946–1949. These data are multiplied by 5/4 in order to approximate the true number of deaths in the period 1946–1950. The mortality rate from laryngeal cancer has been consistently higher in men than in women, latterly by a factor of around four. Cancer of the larynx in men has not changed greatly during the 75 years of observation, remaining between an annual death rate of 1.9 and 2.5 (Figure 1). The most recent mortality rates in women are around one half the corresponding rates in the 1950s (Figure 1).

Cancer of the oesophagus
The coding rubric for cancer of the oesophagus remained unchanged and unique during the period studied. In men and women, the mortality rate has increased by around 50%. However, there are some important differences in the pattern observed. Since 1965, the death rate in women has remained fairly constant while there has been a consistent increase in the death rate observed in men, rising from 4.2 per 100 000 in 1956–1960 to 7.5 per 100 000 in 1991–1995 (Figure 1).

Cancer of the stomach
The coding and publication of data on cancer of the stomach remained unchanged throughout the period of observation. In both gender groups, mortality reached a peak in 1941–1945 and has subsequently experienced a consistent decline. In men the mortality rate peaked at 30 per 100 000 and has declined to 11 per 100 000 in the most recent period. In women, the corresponding decline was from 22 to 5 per 100 000 (Figure 2).



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Figure 2. Cancer of the (A) stomach, (B) intestines, (C) liver and gallbladder, and (D) pancreas in men and women in Ireland. Annual, average age-standardised death rates per 100 000, 1926–1995.

 
Cancer of the intestines
Cancers of the small intestine, large intestine and the rectum have been merged into a single category which has remained available throughout the time period studied. This includes deaths coded to large intestine (not otherwise specified). Mortality rates in both gender groups increased to a peak in the 1940s and then declined until the early 1960s (Figure 2). Thereafter the mortality rate has continued to increase in men (from 19.7 in 1961–1965 to 25.3 in 1991–1995) while it has declined in women from the period 1971–1975 onwards (from 19.4 to 16.0 in 1991–1995).

Cancer of the liver and gallbladder
Although of questionable epidemiological value, these two sites have been combined in the published data for the earlier decades. The combined site has been presented here for completeness (Figure 2). There has been a substantial and consistent decline in mortality rates during the period covered. In men, the death rate fell from 8.1 in 1926–1930 to 1.3 in 1991–1995. In women the corresponding declines were from 9.4 to 1.3 per 100 000 (Figure 2).

Cancer of the pancreas
This rubric was preserved throughout the period studied. Mortality rates in men were consistently higher than in women, although they paralleled one another throughout the study period. Death rates increased consistently until the period 1976–1980 and have declined marginally in both gender groups subsequently (Figure 2).

Cancer of the trachea, bronchus and lung and pleura
This rubric remained consistent throughout the period studied although the identity of cancer of the pleura has been obscured by the all-embracing rubric: for simplicity it shall be referred to as lung cancer. Lung cancer increased in men from an annual death rate of 0.8 per 100 000 in 1926–1930 to reach a peak of 51.6 per 100 000 in 1981–1986 (Figure 3). The rate has subsequently fallen to 46.3 per 100 000 in the final (1991–1995) time period (Figure 3). There is a clear cohort effect underlying this pattern of lung cancer change (Figure 4). In women, the death rate at the beginning of the observation period (0.84 per 100 000) was very similar to that in men. The death rates in women have risen and the peak death rate reached (in 1985–1990 and 1991–1995) was 18 per 100 000 per annum (Figure 3).



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Figure 3. Cancer of the lung in men and women in Ireland. Annual, average age-standardised death rates per 100 000, 1926–1995.

 


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Figure 4. Age-specific cancer of the lung. Mortality rates per 100 000 per annum in men in Ireland, 1926–1995, by birth cohort and year of diagnosis.

 
Cancer of the breast, uterus and ovary
Each of these rubrics remained identifiable throughout the study period although, unfortunately, the use of the term ‘uterus’ means that individual data about cervix and body of the uterus (and endometrium) are lost. Breast cancer increased until it attained an annual rate of 26.4 per 100 000 in the period 1976–1980 and the death rate has subsequently remained fairly constant (Figure 5). Cancer of the uterus decreased from 11.7 per 100 000 in 1926–1930 until it reached 5.1 per 100 000 in the final period, 1991–1995 (Figure 5). Mortality from cancer of the ovary increased consistently throughout the 75 year period, starting at around 2 per 100 000 and rising to an annual death rate of 8.3 per 100 000 (Figure 5).



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Figure 5. Cancer of the breast, ovary and uterus in women in Ireland. Annual, average age-standardised death rates per 100 000, 1926–1995.

 
Cancer of the urinary bladder
Cancer of the bladder remained identifiable throughout the period of the study (Figure 6). The death rate was always higher in men than in women. In men, the death rate increased until it peaked in 1976–1980 (at 4.9 per 100 000) and has subsequently fallen slightly (to reach 4.6 per 100 000 in 1991–1995) (Figure 6). In women, the death rate from bladder cancer has remained fairly constant at around 1.5 per 100 000 per annum (Figure 6).



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Figure 6. Cancer of the (A) bladder and (B) kidney in men and women in Ireland. Annual, average age-standardised death rates per 100 000, 1926–1995.

 
Cancer of the kidney
The number of deaths until 1955 includes the deaths for tumours in the kidneys and suprarenal glands. After 1955 the data include only the number of deaths for tumours in the kidneys: the difference is minimal. Death rates were consistently higher in men than in women throughout the period covered and the death rates have increased in both gender groups, although more strongly among men (Figure 6). In men the annual death rate rose from 0.5 per 100 000 in the first time period and attained an annual death rate of 3.7 per 100 000 in the most recent period (1991–1995) (Figure 6). In women, the death rates more than doubled over the entire time span, from 0.7 per 100 000 in 1926–1930 to reach 1.8 in 1991–1996 (Figure 6).

Cancer of the prostate and testes
These rubrics remained identifiable throughout the period covered. Mortality from cancer of the testes rose to attain a peak in the period 1966–1970 (of 0.82 per 100 000), remained constant over the next decade (at 0.79 per 100 000) and subsequently fell to 0.35 per 100 000 in the final time period (1991–1995) (Figure 7). Cancer of the prostate rose throughout the three-quarters of a century covered by this study, starting at a rate of 3 per 100 000 and rising to a death rate of 17.5 per 100 000 in 1991–1995 (Figure 7).



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Figure 7. Cancer of the prostate and testes in men in Ireland, 1926–1995. Annual, average age-standardised death rates per 100 000.

 
Leukaemia
In the period 1931–1940, the data for leukaemia in Northern Ireland are not available. Moreover, there is no complete information for the time period 1941–1945; the available data cover the period 1944–1945. These data are multiplied by 5/2 in order to approximate the true number of deaths in the period 1941–1945. Leukaemia mortality was higher in men than in women throughout the study period (Figure 8). In men, the death rate peaked in the period 1971–1975 (5.85 per 100 000 per annum) and has subsequently declined (to a rate of 5.1 per 100 000 in 1991–1995) (Figure 8). In women, there has not been much movement of the rate subsequent to 1951–1955 (Figure 8).



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Figure 8. Mortality from (A) leukaemia of all forms; (B) Hodgkin’s disease and (C) thyroid cancer in men and women in Ireland. Annual, average age-standardised death rates per 100 000.

 
Hodgkin’s disease
The data concerning the deaths due to Hodgkin’s disease in the Republic of Ireland are not available in the period 1940–1948. Moreover, the available observations in the time periods 1936–1940 and 1946–1950 do not cover the entire periods. For the period 1936–1940, the number of deaths is multiplied by 5/4 and for the period 1946–1950 by 5/2 in order to approximate the true number of deaths in the two periods. The data concerning deaths due to Hodgkin’s disease in Northern Ireland are not available in the period 1931–1943. Moreover, for the period 1941–1945, the number of deaths has been multiplied by 5/2 in order to approximate the true number of deaths in the period. Mortality from Hodgkin’s disease has always been higher in men than in women. The death rate in each gender group has been declining since the peak attained in the period 1961–1965 (2.1 per 100 000 in men and 1.2 in women). By 1991–1995, these death rates had fallen to 0.7 per 100 000 in men and 0.5 in women (Figure 8).

Cancer of the thyroid
This rubric remained unchanged and unique throughout the period of the study. Survival from thyroid cancer is very good which makes interpretation of temporal trends in mortality more difficult. Thyroid cancer mortality rate was higher in women than in men throughout the study period. In women, the mortality rate peaked in the period 1956–1960 (at 1.1 per 100 000 per annum) and has subsequently declined consistently (to reach 0.5 per 100 000 in 1991–1995) (Figure 8). In men, the death rate has remained unchanged since the start of the 1960s (Figure 8).

All neoplasms
All neoplasms include cancers of all forms and other tumours whether of benign or unspecified behaviour. The data concerning such deaths in the Republic of Ireland are not available before 1927 and in the period 1940–1948. The number of deaths in 1927–1930 and 1936–1939 has been multiplied by 5/4 in order to approximate the true number of deaths in the periods 1926–1930 and 1936–1940, respectively. Moreover, the number of deaths in 1949–1950 is multiplied by 5/2 in order to approximate the true number of deaths in the period 1946–1950. The data concerning the deaths in Northern Ireland are not available before 1944. The number of deaths in 1944–1945 has been multiplied by 5/2 in order to approximate the true number of deaths in the period 1941–1945. 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.


    Discussion
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
This is the first systematic presentation of cancer trends in Ireland, although there have been some previous publications containing information separately for the Irish Republic and Northern Ireland [9, 10]. Although there has been previous work it has tended to focus almost exclusively on particular aspects of individual forms of cancer [1117] or on cancer risk in Irish migrants [18, 19]. Descriptive epidemiology still has an important role to play in describing and helping analyse cancer control possibilities and achievements. Analysis of long time series can give an additional insight into cancer patterns and can help identify significant cancer threats and hazards in communities.

Cancer mortality data exist for Ireland since partition took place in the early 1920s. Of course, cancer incidence data would have been more helpful, but they simply do not exist for the entire country historically and have only become available in more recent years [20, 21]. However, cancer mortality data can be very useful, although issues such as the introduction of successful treatment and abrupt changes in coding practices must be kept in mind when considering such information.

The separate data for the Republic of Ireland and Northern Ireland have been aggregated having been shown not to be significantly heterogeneous when sites and gender groups were considered across the two countries. The aggregations necessary to have comparable and continuous data over the 70 year period has, of course, led to some loss of information. It would have been useful to have separate data on cancer of the pleura, given the major shipbuilding industry which existed in Northern Ireland for many decades. There are known difficulties in coding practices which limit the utility of individual death rates from cancer of the colon and rectum [22] and cancer of the cervix and body of uterus [23]. Thus, although amalgamation of these rubrics means that no data are discarded, it still represents a loss of useful information.

The overall cancer mortality rates in Ireland are slightly below the European average in men and above the average in women [24]. The overall cancer death rate is dominated by lung cancer and it is reassuring to see a fall in mortality clearly established in men (Figure 3). This decline has occurred later than among men in the UK [25]. There is a suggestion of stabilisation in the death rate from lung cancer among Irish women in the last time period which, if it continues, would be a source of satisfaction. Tobacco control activities in Ireland are hopefully having the desired effect of reducing tobacco-related cancers but there are no grounds for complacency. It is encouraging to note that the majority of smokers wish to quit smoking and many wish to reduce their smoking activity [26].

The aetiology of cancers of the oral cavity, oesophagus and larynx have strong similarities: independent effects of cigarette smoking, alcohol consumption and the joint (multiplicative) effects of both risk factors influence the risk of all three forms of cancer [27]. However, the pattern of temporal change in death rates from all three cancers in Ireland is quite different. The most recent increases seen in oral cavity and oesophagus cancers in men, which have been taking place for a longer time for the latter, probably reflect an increasing alcohol consumption: it is strange, however, that no change is apparent in cancer of the larynx over the same period (Figure 1). It could be that the effect of alcohol on larynx cancer is less than that for oral cavity and oesophageal cancers. Some of the leading regional rates in oesophageal cancer in women in Europe have been apparent in regions of Ireland [22]. The diverging trends seen in oesophageal cancer in men (increasing noticeably) and women (decreasing slowly) in Ireland is noteworthy and deserves some further attention. For similar reasons, so too does colorectal cancer.

Long-time decreases in stomach cancer in both gender groups is a common finding in Ireland as well as most other western European countries (Figure 2), as are the recent declines in intestinal cancer. The declines in death rates from cancer of the liver and gallbladder are quite noticeable and difficult to explain simply (although the incorrect attribution of metastatic liver cancers as primary tumours in the past may be an important contributing factor). There has been no major change in coding practice which could explain this nor any major change in risk factors which could explain this change: hepatitis in Ireland over the time period is not a major factor nor is changing alcohol consumption. The increase in death rate from pancreas cancer in the early part of the century is a notable feature of the current data set as is the recent decrease in death rates seen in both gender groups.

Some of the highest regional rates in the European Community for breast cancer have been found in regions of both Northern Ireland and the Republic of Ireland [22]. The overall breast cancer mortality rate in Ireland is among the highest in Europe [24]. Although the death rate has increased from 1926 until 1975, it appears to have stabilised subsequently (Figure 5), although it is not yet decreasing. The impact of a national population-based screening programme in Northern Ireland in 1988 has had an impact on reducing death rates in middle-aged women who have been eligible for screening (P. Boyle, S. Golia, C. Robertson, N. O’Higgins, unpublished data). In contrast, there has been no such change in the Republic of Ireland in this latter time period (1991–1995) when there has been no organised national screening programme. This supports the efficacy of organised mammographic screening programmes.

The strong decline in cancer of the uterus is probably a reflection of cervical cancer screening although further decline could be possible due to the introduction of an organised programme throughout the island. The increasing death rate from ovarian cancer is consistent and substantial and could usefully be investigated.

The increase in prostate cancer (Figure 7), greater than five-fold over the 70 years covered, reflects the increasing importance of this disease in men. Prostate cancer is the third commonest form of cancer death in Irish men at the present time after lung cancer and intestinal cancer. Unless some successful action is initiated soon, this situation will change for the worse, especially given the striking changes in lung cancer. The nature of this action is not known at present. In particular, prostate cancer screening remains controversial [28] although there have been some strong suggestions of its efficacy in populations with high-quality treatment facilities available [29].

The decline in the death rate from testicular cancer (Figure 7) and Hodgkin’s disease (Figure 8) both occur at similar points when new, effective therapy has been introduced: similar changes have been seen for both testicular cancer [3033] and Hodgkin’s disease [34, 35] in other communities. It is obvious that the advances in therapy which have been effective against these cancers have been introduced successfully into clinical practice in Ireland to the benefit of patients with these diseases. This is also true to some extent for leukaemia (Figure 8), where a decline has also taken place.

Generally, examination of this long time series of mortality data from Ireland provides reassuring information. This analysis demonstrates that there is no overall cancer epidemic building up; that the death rates from most forms of cancer considered are declining; that major treatment advances have been incorporated effectively into clinical practice; that progress is apparent in tobacco control and that there is no evidence from these data of a major new carcinogen being introduced into the Irish environment (apart from tobacco). Currently, the overall cancer death rate in Irish men is in line with other European countries, although the high mortality rate for cancer in women, among the top fifth of national cancer mortality rates in European countries, highlights an important priority.

However, it has recently been shown, in an evaluation of the Europe Against Cancer programme, that between 1985 and 2000, Ireland was tenth out of 15 member states in terms of reductions in cancer mortality (P. Boyle, A. d’Onofrio, P. Maisonneuve et al., unpublished data). There is clearly scope for improving this situation, notably with the introduction of an effective population-based screening programme for cervix and breast cancer, continuing successful tobacco control initiatives and, more controversially, with consideration of a National Prostate Cancer Screening programme. There could be some major local factor contributing to the divergent patterns seen in cancers of the oral cavity, larynx and oesophagus and, together with the aetiology of breast and ovarian cancer, it may be worthwhile pursuing. These are areas worthy of further investigation and research.

These data provide a baseline for further cancer control and treatment activities in Ireland.


    Acknowledgements
 
It is a pleasure to acknowledge that this work was conducted within the framework of support from the Italian Association for Cancer Research (Associazone Italiana per la Ricerca sul Cancro).


    Footnotes
 
+ Correspondence to: Dr P. Boyle, Division of Epidemiology and Biostatistics, European Institute of Oncology, Via Ripamonti 435, 20141 Milan, Italy. Tel: +39-02-5748-9815; Fax: +39-02-5748-9922; E-mail: director.epi{at}ieo.it Back


    References
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
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