Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study

In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24 years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls. The mean ages of cases and controls were 16.5 and 16.6 years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10 years) users: 22% overall, 51% in the 20-24-year-olds. Most tumours were of the neuroepithelial type (NBT; n = 671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15-19 years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour. Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure. Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk.

Social mobility and healthy behaviours from a gender perspective in the Spanish multicase-control study (MCC-Spain)

There is evidence for the influence of socioeconomic status (SES) on healthy behaviours but the effect of social mobility (SM) is not yet well known. This study aims to analyse the influence of origin and destination SES (O-SES and D-SES) and SM on healthy behaviours and co-occurrence, from an integrated gender and age perspective. Data were obtained from the controls of MCC-Spain between 2008-2013 (3,606 participants). Healthy behaviours considered: healthy diet, moderate alcohol consumption, non-smoking and physical activity. SM was categorized as stable high, upward, stable medium, downward or stable low. Binary and multinomial logistic regression models were adjusted. Those aged <65, with a low O-SES, D-SES and stable low SM are less likely to have healthy behaviours in the case of both women (physically active: OR = 0.65 CI = 0.45-0.94, OR = 0.71 CI = 0.52-0.98, OR = 0.61 CI = 0.41-0.91) and men (non-smokers: OR = 0.44 CI = 0.26-0.76, OR = 0.54 CI = 0.35-0.83, OR = 0.41 CI 0.24-0.72; physically active: OR = 0.57 CI = 0.35-0.92, OR = 0.64 CI = 0.44-0.95, OR = 0.53 CI = 0.23-0.87). However, for those aged ≥65, this probability is higher in women with a low O-SES and D-SES (non-smoker: OR = 8.09 CI = 4.18-15.67, OR = 4.14 CI = 2.28-7.52; moderate alcohol consumption: OR = 3.00 CI = 1.45-6.24, OR = 2.83 CI = 1.49-5.37) and in men with a stable low SM (physically active: OR = 1.52 CI = 1.02-1.26). In the case of men, the same behaviour pattern is observed in those with a low O-SES as those with upward mobility, with a higher probability of co-occurring behaviours (three-to-four behaviours: OR = 2.00 CI = 1.22-3.29; OR = 3.13 CI = 1.31-7.48). The relationship of O-SES, D-SES and SM with healthy behaviours is complex and differs according to age and gender.

Trends in mortality from cutaneous malignant melanoma in Spain (1982-2016): sex-specific age-cohort-period effects

BACKGROUND

Mortality from malignant cutaneous melanoma increased alarmingly during the second half of the 20th century in Spain and other European countries.

OBJECTIVE

The aim was to analyse sex- and age-specific trends in melanoma mortality in Spain in the period 1982-2016.

METHODS

European age-standardized melanoma mortality rates during the period 1982-2016 were calculated from mortality figures provided by the National Statistics Institute. Joinpoint regressions were used to identify significant points of change in trends and to compute average annual per cent change (AAPC). Age-cohort-period models were fitted to explore the effect of these variables on mortality.

RESULTS

During the period 1982-2016, age-standardized melanoma mortality rates increased in Spain from 0.90 to 1.80 deaths per 100 000 people in men and from 0.64 to 1.11 per 100 000 in women, rising noticeably from 1982 to 1995 in both sexes and in all age groups. From the mid-90s different trends were observed depending on sex and age: there was a decrease in mortality in the population younger than 45 years (AAPC -2 in both sexes) and aged 45-64 years (AAPC -1 among men and -0.2 among women), but in the group over 64 years rates continued to increase (AAPC 1.7 and 0.2, respectively, for men and women). The mortality sex ratio decreased in the younger population but increased in older individuals. A cohort effect was observed with lower mortality in the cohorts born after 1943 in men and 1956 in women. There was also a period effect with decreased mortality rates at the beginning of the 1990s.

CONCLUSIONS

Melanoma mortality rates in Spain increased during the last decades of the 20th century; however, later they stabilized in women and began to decrease in younger cohorts and middle-aged men. Promotion of primary and secondary prevention measures should continue, with particular emphasis on males over 65 years.

Compositional analysis of dietary patterns

Instead of looking at individual nutrients or foods, dietary pattern analysis has emerged as a promising approach to examine the relationship between diet and health outcomes. Despite dietary patterns being compositional (i.e. usually a higher intake of some foods implies that less of other foods are being consumed), compositional data analysis has not yet been applied in this setting. We describe three compositional data analysis approaches (compositional principal component analysis, balances and principal balances) that enable the extraction of dietary patterns by using control subjects from the Spanish multicase-control (MCC-Spain) study. In particular, principal balances overcome the limitations of purely data-driven or investigator-driven methods and present dietary patterns as trade-offs between eating more of some foods and less of others.

Abstract P3-09-01: Withdrawn

This abstract was withdrawn by the authors.

Abstract P3-09-10: Withdrawn

This abstract was withdrawn by the authors.

Serum PCB levels in a representative sample of the Spanish adult population: the BIOAMBIENT.ES project

This manuscript presents the levels of six indicator polychlorinated biphenyl (PCB) congeners (IUPAC nos. 28, 52, 101, 138, 153 and 180) in the serum of 1880 individuals from a representative sample of the Spanish working population recruited between March 2009 and July 2010. Three out of the six PCBs studied (180, 153 and 138) were quantified in more than 99% of participants. PCB 180 was the highest contributor, followed by PCBs 153 and 138, with relative abundances of 42.6%, 33.2% and 24.2%, respectively. In contrast, PCBs 28 and 52 were detected in only 1% of samples, whereas PCB 101 was detectable in 6% of samples. The geometric mean (GM) for ΣPCBs138/153/180 was 135.4 ng/g lipid (95% CI: 121.3-151.2 ng/g lipid) and the 95th percentile was 482.2 ng/g lipid. Men had higher PCB blood concentrations than women (GMs 138.9 and 129.9 ng/g lipid respectively). As expected, serum PCB levels increased with age and frequency of fish consumption, particularly in those participants younger than 30 years of age. The highest levels we found were for participants from the Basque Country, whereas the lowest concentrations were found for those from the Canary Islands. The Spanish population studied herein had similar levels to those found previously in Greece and southern Italy, lower levels than those in France and central Europe, and higher PCB levels than those in the USA, Canada and New Zealand. This paper provides the first baseline information regarding PCB exposure in the Spanish adult population on a national scale. The results will allow us to establish reference levels, follow temporal trends and identify high-exposure groups, as well as monitor implementation of the Stockholm Convention in Spain.

Do sex and site matter? Different age distribution in melanoma of the trunk among Swedish men and women

BACKGROUND

Recent research on cutaneous malignant melanoma (CMM) points to the coexistence of several biological pathways linked to the anatomical site of the lesion, which could lead to this neoplasm. Although the different anatomical distribution of CMM by sex is usually attributed to gender-specific patterns of sun exposure, it has been suggested that an alternative explanation might lie in gender-specific site susceptibility.

OBJECTIVES

This paper aimed at analysing the age distribution of CMM by site and sex to gain in-depth knowledge of differences between the sexes.

METHODS

Using a large Swedish cohort comprising 2 992 166 workers, Poisson models were fitted to estimate age-specific incidence rates by site and sex, duly adjusted for several factors that might account for changes in environmental exposures (period, birth cohort, socioeconomic level, latitude and rurality).

RESULTS

Incidence rates were 17.4 cases per 100 000 person-years in men and 16.5 in women. Sex differences were particularly striking for CMM of the trunk, where both crude and adjusted incidence rates displayed a steady increase with age in men, but reached a plateau in women at around four cases per 100 000 person-years from the 40-45-year age group (perimenopausal period) upwards. There was an almost fivefold increase in the sex ratio for this body site between the younger and older age groups, a difference which could not be attributed to period or cohort effects.

CONCLUSIONS

If different aetiological pathways can be assumed to lead to melanoma, then disparities between men and women, particularly in CMM of the trunk, suggest that a possible interaction between site and sex should be borne in mind.

Acute health problems among subjects involved in the cleanup operation following the Prestige oil spill in Asturias and Cantabria (Spain)

The purpose of this study was to evaluate exposure conditions and acute health effects in subjects participating in the Prestige oil spill cleanup activities and the association between these and the nature of the work and use of protection devices in the regions of Asturias and Cantabria (Spain). The sample comprised 400 subjects in each region, selected from a random sampling of all persons involved in cleanup activities, stratified by type of worker and number of working days. Data were obtained via a structured questionnaire and included information on specific tasks, number of working days, use of protective materials, and acute health effects. These effects were classified into two broad groups: injuries and toxic effects. Data analysis was performed using complex survey methods. Significant differences between groups were evaluated using Pearson's chi(2) test. Unconditional logistic regression was used to compute odds ratios and 95% confidence intervals. Bird cleaners accounted for the highest prevalence of injuries (19% presented with lesions). Working more than 20 days in highly polluted areas was associated with increased risk of injury in all workers. Occurrence of toxic effects was higher among seamen, possibly due to higher exposure to fuel oil and its components. Toxic effects were more frequent among those working longer than 20 days in highly polluted areas, performing three or more different cleaning activities, having skin contact with fuel oil on head/neck or upper limbs, and eating while in contact with fuel or perceiving disturbing odors. No severe disorders were identified among individuals who performed these tasks. However, potential health impact should be considered when organizing cleanup activities in similar environmental disasters.

Municipal pleural cancer mortality in Spain

BACKGROUND

Pleural cancer is a recognised indicator of exposure to asbestos and mesothelioma mortality.

AIMS

To investigate the distribution of municipal mortality due to this tumour, using the autoregressive spatial model proposed by Besag, York, and Mollie.

METHODS

It was possible to compile and ascertain the posterior distribution of relative risk on the basis of a single Bayesian spatial model covering all of Spain's 8077 municipal areas. Maps were plotted depicting standardised mortality ratios, smoothed relative risk (RR) estimates, and the distribution of the posterior probability that RR >1.

RESULTS

There was a higher risk of death due to pleural cancer in well defined towns and areas, many of which correspond to municipalities where asbestos using industries once existed for many years, the prime example being the municipal pattern registered for Barcelona Province. The quality of mortality data, the suitability of the model used, and the usefulness of municipal atlases for environmental surveillance are discussed.

Situación del cáncer en España: incidencia

It is estimated that at present in Spain around 162,000 cases of cancer are diagnosed each year (without including non-melanoma skin cancer), of which 25,600 correspond to colorectal carcinomas, which is the most frequent of all tumours in absolute terms. The next tumour in terms of frequency is lung cancer with 18,800 new cases, followed by breast cancer in women with 15,979 cases. When the incidence of cancer is compared with that in neighbouring countries, Spain shows adjusted rates in men higher than those of the average for the EU, occupying the 5th place. However, in women, Spain shows the lowest rates together with Greece. Spain occupies the first place for cancer of the bladder in men, with rates that are considerably higher than those of the rest of the countries. It is important to verify the increase underway in the incidence of cancer in Spain and the contrast that this represents facing the evolution of mortality. For many important tumoral localisations (lung, stomach, bladder), the population registers do not cover the provinces where there is a greater mortality.

Cutaneous melanoma: hints from occupational risks by anatomic site in Swedish men

AIMS

To improve knowledge of the epidemiology of melanoma by comparing occupational risks of cutaneous melanoma (CM) by anatomic site in Swedish workers.

METHODS

Male workers employed in 1970 and living in the country in 1960 were followed up from 1971 to 1989 using the Swedish Registers of Death and Cancer. A more specifically exposed subcohort included men reporting the same occupation in 1960 and 1970. For each location, occupational risk ratios (RRs) were extracted from Poisson regression models adjusted by age, period, town size, and geographical area. To diminish the influence of socioeconomic factors, intrasector analyses, comparing only jobs belonging to the same occupational sector, were performed. Risk patterns for different locations were compared.

RESULTS

High RRs for different sites were found among workers exposed to UV sources (dentists, physiotherapists, and lithographers), and sun exposed workers (harbour masters, and lighthouse/related work). Risk excesses were seen in fur tailors, tanners/fur dressers, patternmakers/cutters, electrical fitters/wiremen, telephone/telegraph installers/repairmen, and some glass/pottery/tile workers. Results for lower and upper limbs were significantly correlated but somewhat independent of those found in thorax, the most frequent location. Correlation between head/neck and thorax was moderate. Specific risk excesses were found for rolling mill workers in head/neck, for chimney sweeps in upper limbs, and for aircraft pilots/navigators/flight engineers in lower limbs.

CONCLUSIONS

High RRs in the trunk among occupations with UV exposure from artificial sources suggest an effect not restricted to exposed sites. An unusual distribution of cases and RRs in chimney sweeps, rolling-mill, or glass/pottery/tile workers suggests local effects of exposures. The not previously reported risk excess in this job and in fur related processes, and the RR in electrical fitters and telephone/telegraph installers deserve further investigation. Disparities between locations, as RRs in thorax and limbs, may reflect differences in aetiological mechanisms.

[Postoperative patient-controlled analgesia is more effective with epidural methadone than with intravenous methadone in thoracic surgery]

OBJECTIVE

To compare the efficacy and side effects of epidural and intravenous methadone for postoperative patient-controlled analgesia (PCA) after thoracic surgery.

PATIENTS AND METHODS

A randomized, single-blind trial enrolling 30 patients distributed in 2 groups to receive intravenous methadone (ivPCA group) or epidural methadone (epPCA group). Patients in both groups were administered a loading dose of 0.05 mg.kg-1 followed by infusion of 0.5 mg.h-1. The patients could self-dose 0.5 mg with a lock-out interval of 10 minutes and a maximum of 4 doses per hour. Patient characteristics, type and duration of surgery and fentanyl dose were recorded. Pain was assessed on a visual analog scale (VAS). Level of sedation, respiratory rate and occurrence of nausea, vomiting and pruritus were also recorded over the first 24 hours.

RESULTS

The 2 groups were comparable. Pain was greater in the ivPCA group than in the epPCA group in the second hour (VAS 3.93 +/- 1.9 and 2.4 +/- 1.65, respectively; P < .05) and the third hour (VAS 3.57 +/- 1.65 and 1.5 +/- 1.16, respectively; P < .05). The total dose of methadone administered was 25.34 +/- 5.65 mg in the ivPCA group and 18.82 +/- 3.52 mg in the epPCA group (P < .002). There were no significant differences in side effects.

CONCLUSIONS

The results suggest that epidural methadone has an intrinsic spinal effect regardless of whether or not there is extra-spinal action arising from syste mic absorption. Epidural methadone provides a more adequate analgesic effect in less time and at a lower dose. Both approaches provide good postoperative analgesia with few side effects.

Stomach cancer and occupation in Sweden: 1971-89

OBJECTIVES

To examine the relation between gastric cancer and occupation among men and women gainfully employed in 1970 in Sweden for the period 1971-89 and, more specifically, to evaluate whether any excess of incidence of gastric cancer had also occurred among the subcohort of people reporting the same occupation in 1960 and 1970.

METHODS

In both sexes and cohorts, relative risks adjusted for age, period of diagnosis, and geographical risk area were computed for occupational codes specified at one, two, or three level (occupational sector, occupational group, and occupation, respectively). Relative risks were calculated with all other occupations as reference and then, to take socioeconomic status into account, solely other occupations within the same occupational sector were used.

RESULTS

Among men, occupations with increased risk included miners and quarrymen, construction and metal processing workers, supporting the possible causative role of dusty environments in stomach cancer. In men, the results also provide support for increased risks among electrical and mechanical engineers, fishermen, petrol station workers, motor vehicle drivers, butchers and meat preparers, dockers, freight handlers, launderers and dry cleaners. Furthermore, it is worth noting interesting results for women, whose occupational risks have been studied less. Excess risks were found for practical nurses, cashiers, bank employees, engineering and electronic industry workers, food industry, housekeeping and cleaning workers. Due to the many occupations studied, several significant associations may be expected by chance.

CONCLUSIONS

The study is explorative but provides support for the relations suggested previously between occupational exposure to dusty environments and stomach cancer, together with some new high risk occupations which should be further studied.

Solid-tumor mortality in the vicinity of uranium cycle facilities and nuclear power plants in Spain

To ascertain solid tumor mortality in towns near Spain's four nuclear power plants and four nuclear fuel facilities from 1975 to 1993, we conducted a mortality study based on 12,245 cancer deaths in 283 towns situated within a 30-km radius of the above installations. As nonexposed areas, we used 275 towns lying within a 50- to 100-km radius of each installation, matched by population size and sociodemographic characteristics (income level, proportion of active population engaged in farming, proportion of unemployed, percentage of illiteracy, and province). Using log-linear models, we examined relative risk for each area and trends in risk with increasing proximity to an installation. The results reveal a pattern of solid-tumor mortality in the vicinity of uranium cycle facilities, basically characterized by excess lung [relative risk (RR) 1.12, 95% confidence interval (CI), 1.02-1.25] and renal cancer mortality (RR 1.37, 95% CI, 1.07-1.76). Besides the effects of natural radiation, these results could well be evincing the influence on public health exerted by the environmental impact of mining. No such well-defined pattern appeared in the vicinity of nuclear power plants. Monitoring of cancer incidence and mortality is recommended in areas surrounding nuclear fuel facilities and nuclear power plants, and more specific studies are called for in areas adjacent to installations that have been fully operational for longer periods. In this regard, it is important to use dosimetric information in all future studies.

Leukemia, lymphomas, and myeloma mortality in the vicinity of nuclear power plants and nuclear fuel facilities in Spain

Mortality due to hematological tumors in towns near Spain's seven nuclear power plants and five nuclear fuel facilities during the period 1975-1993 was ascertained. The study was based on 610 leukemia-, 198 lymphoma-, and 122 myeloma-induced deaths in 489 towns situated within a 30-km radius of such installations. As control areas, we used 477 towns lying within a 50- to 100-km radius of each installation, matched by population size and a series of sociodemographic characteristics (income level, proportion of active population engaged in farming, proportion of unemployed, percentage of illiteracy, and province). Relative risk (RR) for each area and the trends in risk with increasing proximity to an installation were analyzed using log-linear models. None of the nuclear power plants registered an excess risk of leukemia-induced mortality in any of the surrounding areas. Excess risk of leukemia mortality was, however, observed in the vicinity of the uranium-processing facilities in Andújar [RR, 1.30; 95% confidence interval, 1.03-1.64] and Ciudad Rodrigo (RR, 1.68; 95% confidence interval, 0.92-3.08). Excess risk of multiplemyeloma mortality was found in the area surrounding the Zorita nuclear power plant. Statistical testing revealed that, with the single exception of multiple myeloma, none of the tumors studied showed evidence of a rise in risk with proximity to an installation. No study area yielded evidence of a raised risk of leukemia mortality among persons under the age of 25 years. More specific studies are called for in areas near installations that have been fully operational for longer periods. In this connection, stress should be laid on the importance of using dosimetric information in all future studies.

Brain cancer incidence in the provinces of Zaragoza and Navarre (Spain): effect of age, period and birth cohort

Several studies have detected increases in malignant brain tumour incidence and mortality rates particularly among the elderly. We analyzed time trends in malignant brain tumors incidence in Zaragoza over the period 1973-1990 and Navarre over the period 1973-1991, two Spanish provinces that have been collecting data through their respective Cancer Registries for the last 20 years, using Poisson regression analysis of age, period of diagnosis and cohort. In general, age-adjusted rates showed a steady rise in both registries, except in the case of females in Navarre, for whom a decrease in risk was observed for the last period, 1988-1991. This increase is a reflection of the rise in incidence experienced by the elderly, since the cohorts successively register rates that are stable over time, and even downward in the case of females in Navarre. The risk run by generations born circa 1920-1930 was the highest encountered. Rates were higher in Navarre in both sexes and for all but the last period in females, when rates on the two registers stood level. Increasingly generalised use of CT scanning and magnetic resonance in the 1980s in Spain, coupled with better and more effective health care access for the elderly, are factors that may well have some bearing on these findings.

[Air pollutants and their monitoring]

Some basic concepts regarding air pollution are set out. Although, from a health care standpoint, our interest revolves around the impact which pollution has on human health, it being important to ascertain the main pollutants, the sources of emissions, the physiochemical properties thereof, the sampling and analysis methods which are used at the air pollution control stations, the limits set by the laws currently in impact and the World Health Organization recommendations with regard to the levels of immission. This study reviews these concepts with regard to the pollutants which have been analyzed in the Spanish Multicenter Study of Air Pollution and Mortality (EMECAM): particles, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3). For this purpose, the most recent publications on this subject have been used, including part of what is going to be the line around which all of the measures aimed at combating air pollution are going to be revolving in the very near future, that is, the new set of European Union Directives (some currently in the proposal stage) and the latest recommendations (not as yet published) of the World Health Organization. Lastly, a wide range of aspects are set out which involve Public Health in the field of air pollution, despite the monitoring and control thereof falling to the environmental affairs authorities in terms of government organization.

Malignant brain tumour mortality among children and adolescents: geographical distribution in Spain

Log-linear Poisson mixed models were used to study provincial malignant brain tumour (MBT) mortality among children and adolescents in Spain (1975-1992) in order to investigate the influence of specific socio-economic factors and to produce smoothed estimators of standardised mortality ratios (SMRs). Interdependence between geographical units was taken into account by including provinces as random effect terms nested with the corresponding Autonomous Region (Spain's administrative divisions). MBT mortality showed a positive association with three variables: non-cancer-related infant mortality; percentage of provincial land surface area devoted to agriculture; and industrial/construction activity. According to the final model, SMRs increased by 4% with every 10% rise in the area devoted to agriculture, with a 4% excess risk predicted for every increase in non-cancer-related infant mortality of 1 per 1000 person-years, and a 7% excess risk for contiguous categories of industrial/construction activity. By smoothing extreme values caused by random variability, the regression model yielded a reasonable estimation of SMRs. While infant mortality may be linked to the quality of medical care available, the relationship seen between MBT mortality and agricultural area accords with the excess risk reported for farmers' offspring. Finally, industrial activity might be regarded as a risk factor or as a marker of other conditions also associated with these tumours.

Rising incidence of non-Hodgkin's lymphoma in Spain: analysis of period of diagnosis and cohort effects

Incidence trends in non-Hodgkin's lymphomas for the period 1973-1991 were studied using data from Spain's Zaragoza and Navarre registries. The overall rate of increase was 5.8% per year. Age-period-cohort models were used, also including sex and registry as explanatory variables. In these models, the variable period was categorized according to the observed changes in diagnostic availability during the length of the study. Non-Hodgkin's lymphomas increased with age, and rates were 31% lower in women. Incidence was almost 50% higher in Navarre, but differences in registry procedures might account for this discrepancy. The rise affects all adult age groups and seems to be the result of changes related not only to the period of diagnosis, mainly ascribable to improvements in diagnostic and coding practices, but also to the birth cohort. According to the model, the risk increased with on-coming generations at a rate of 1.5% per year. The AIDS epidemic in Spain is unable to explain this trend, although it may well exert a stronger influence in the future. Additional knowledge is required to understand the observed rise and to prevent the growing numbers of cases that are expected in years to come.

Age-period-cohort modeling of colorectal cancer incidence and mortality in Spain

Spain registers a much lower rate of colorectal cancer incidence and mortality than do other European countries, yet the rises observed in the adjusted rates over recent decades led us to attempt to monitor the trends over time using Poisson log-linear models. Incidence data were furnished by the Zaragoza and Navarre population-based cancer registries, whereas mortality data corresponded to Spain as a whole. For trend evaluation purposes, we made use of invariant parameters from age-period-cohort models (net drift and curvature) and a restriction of the cohort-effect slope range. The results suggest the presence of a marked rise in incidence of colorectal cancer for both sexes and across all age groups in the provinces studied. The rise in mortality was less pronounced than the rise in incidence and seemed to coincide with a marked cohort effect present throughout the study period. Both in incidence and mortality, the increases were more pronounced among men. When studied jointly, incidence and mortality trends tend to be complementary, rendering an approach of this nature especially important in sites with better survival, such as the case in point.

Time trend and age-period-cohort effects on gastric cancer incidence in Zaragoza and Navarre, Spain

STUDY OBJECTIVE

To describe time trends in gastric cancer incidence in Zaragoza and Navarre, and to investigate time period and birth cohort as determinants of such trends.

DESIGN

Cases from two registries were grouped into five year intervals and the following were calculated: age specific and sex specific incidence rates, and the male to female ratio. Log linear models including age, period of diagnosis, and birth cohort were fitted.

SETTING

The Zaragoza Cancer Registry covers the province of Zaragoza, which has a population of 824,776 (403,755 men and 421,021 women). The Navarre Cancer Registry covers the province of Navarre which has 512,512 inhabitants (254,786 men and 257,726 women). In both cases population figures were based on the late census.

PATIENTS

These comprised incident cases of gastric cancer reported to the Zaragoza Cancer Registry in 1963-87 and to the Navarre Cancer Registry in 1973-87.

MAIN RESULTS

Navarre registered higher adjusted and cumulative rates than Zaragoza for both sexes. In both provinces, there were relative declines in the rates for men and women of 3% and 4% respectively per year. In Zaragoza, the risk of developing stomach cancer fell in generations born between 1888 and 1933, and rose in subsequent birth cohorts in both sexes, while in Navarre the cohort effect showed an approximately linear risk for both sexes. Both provinces recorded increases in risk associated with cohorts born between 1933 and 1943.

CONCLUSION

The incidence rates of gastric cancer fell in both Zaragoza and Navarre. The reason for the greater incidence of gastric cancer in Navarre remains unknown. Trends in rates seem to be mainly linked to birth cohort. Increases in risk in generations born after 1933 may be ascribable to nutritional deficiencies in the early years of life.

Gastric cancer in the European Union (1968-1992): mortality trends and cohort effect

PURPOSE

To analyze patterns and trends in gastric cancer mortality in the European Union (EU) over the period 1968-1992, paying special attention to changes associated with birth cohort.

METHODS

Poisson log-linear models were used to quantify geographic differences and relative annual changes. To assess trends associated with birth cohort, invariant parameters from sex-specific age-period-chohort models (net drift and curvature), for each country, were used to choose a restricted slope range for cohort effect.

RESULTS

Gastric cancer mortality declined throughout the EU. The male-to-female ratio stood at around 2 in all countries, yet showed a slight rise over time. Portugal reported the highest age-adjusted rates for men and women (45.63 and 23.31 per 100,000 person-years, respectively). The rate ratio between two extreme countries (Portugal/Denmark) exceeded 3. Quantitative intercountry differences were found in trend slopes, with a decrease of 5% per annum in Finland. Risk of dying associated with birth cohort decreased over successive generations. Small local rises in risk, in almost all countries among generations born around the 1940s, support the importance of diet early in life in the etiology of gastric cancer.

CONCLUSIONS

Despite the substantial decline in gastric cancer mortality witnessed in the EU, stress must be accounted for the wide differences among countries and the smaller decline in the youngest generations, particularly among women. This latter finding suggests a possible stabilization or even a rise in the rates in future, rendering it important for these trends to be monitored over the next few years.

Childhood cancer incidence in Zaragoza and Navarre (Spain): 1973-1987

Patterns and trends in childhood cancer incidence for Navarre and Zaragoza registries were studied over the 15-year period, 1973-1987. Overall cancer rates and rates for 10 specific types of cancer were analysed using a log-linear Poisson model or, alternatively, a gamma-Poisson model whenever overdispersion was present, with age, sex, registry and period being used as predictor variables. Childhood cancer was 30% more frequent in boys than in girls, and, except for lymphomas and bone tumours, incidence decreased remarkably with age. Adjusted rates were high in comparison with other European countries, particularly in the case of non-Hodgkin's lymphomas. Cancer rates proved somewhat higher in Navarre, but this difference attained statistical significance solely in the case of central nervous system tumours (rate ratio = 1.75; 95% confidence interval 1.21-2.54). A significant rise in overall incidence was observed (11% 5-yearly increase) due mainly to the upward trend in central nervous system tumours. While the rise in these tumours coincides with the period which witnessed the spread of computerised tomography in Spain, the trend nevertheless held steady over the last 5-year period, when access to this diagnostic technique had already become generalised nationwide.