Trends in cancer incidence and mortality in Scotland: description and possible explanations

Variants near CHRNA3/5 and APOE have age- and sex-related effects on human lifespan

Lifespan is a trait of enormous personal interest. Research into the biological basis of human lifespan, however, is hampered by the long time to death. Using a novel approach of regressing (272,081) parental lifespans beyond age 40 years on participant genotype in a new large data set (UK Biobank), we here show that common variants near the apolipoprotein E and nicotinic acetylcholine receptor subunit alpha 5 genes are associated with lifespan. The effects are strongly sex and age dependent, with APOE ɛ4 differentially influencing maternal lifespan (P=4.2 × 10⁻¹⁵, effect −1.24 years of maternal life per imputed risk allele in parent; sex difference, P=0.011), and a locus near CHRNA3/5 differentially affecting paternal lifespan (P=4.8 × 10⁻¹¹, effect −0.86 years per allele; sex difference P=0.075). Rare homozygous carriers of the risk alleles at both loci are predicted to have 3.3–3.7 years shorter lives.

Understanding the genetic influences on human aging requires a large number of subjects for a study of sufficient power. Here, Jim Wilson and colleagues use information on parental ages at death to show that common variants near the genes for apolipoprotein E and nicotinic acetylcholine receptor subunit alpha 5 are associated with longer lifespan.

Higher incidence of premenopausal breast cancer in less developed countries; myth or truth?

Background

Fundamental etiologic differences have been suggested to cause earlier onset of breast cancer in less developed countries (LDCs) than in more developed countries (MDCs). We explored this hypothesis using world-wide breast cancer incidence data.

Methods

We compared international age-standardized incidence rates (ASR) of pre- (<50 years) and postmenopausal (≥50 years) breast cancers as well as temporal trends in ASRs of pre-and postmenopausal breast cancer among selected countries during 1975–2008. We used joinpoint log-linear regression analysis to estimate annual percent changes (APC) for premenopausal and postmenopausal breast cancer in the northern Europe and in Black and White women population in the US.

Results

Premenopausal breast cancers comprised a substantially higher proportion of all incident breast cancers in LDCs (average 47.3%) compared to MDCs (average 18.5%). However, the ASR of premenopausal breast cancer was consistently higher in MDCs (29.4/100,000) than LDCs (12.8/100,000). The ASR of postmenopausal cancer was about five-fold higher in the MDCs (307.6/100,000) than the LDCs (65.4/100,000). The APC of breast cancer in Denmark was substantially higher in postmenopausal (1.33%) than premenopausal cancer (0.98%). Higher incidence of breast cancer among the white than black women in the US was pertained only to the postmenopausal cancer.

Conclusion

The substantial and consistent lower age-specific incidence of breast cancer in LDCs than in MDCs contradicts the theory of earlier onset. Demographic differences with fewer old women in LDCs and lower prevalence of risk factors of postmenopausal cancer are the most likely explanation to the lower mean age at diagnosis in these countries.

Epidemic of non-hodgkin lymphoma in new zealand remains unexplained

Background. Non-Hodgkin lymphoma (NHL) incidence rates have increased considerably in New Zealand. Methods. Incidence and mortality rates for NHL from 1981 to 2010 were calculated. Trends in age-specific rates were analysed and age-period-cohort models fitted to explore generation-specific changes in incidence and mortality. Results. NHL incidence increased by 67% for men and 74% for women between the 1981–1985 and 2006–2010 time periods in New Zealand. For women born about 1936 and men born about 1946, NHL incidence and mortality have diverged suggesting an improved prognosis for recent generations. Conclusion. The strong generation effects suggest that an exposure before 25 years of age is of major importance in determining the lifetime risk of NHL in New Zealand. NHL incidence rates in New Zealand will continue to increase in the future and probably more in females than males, as generations with increased risk age. Current hypotheses for the cause of NHL do not explain the trends observed. A decline in the prevalence of a protective factor may have also contributed to these trends. Examination of trends for subtypes of NHL and innovative testable hypotheses that may explain these trends are needed.

Altered bone status in unilateral testicular cancer survivors: Role of CYP2R1 and its luteinizing hormone-dependency

BACKGROUND

Recent data suggest a potential role of testis in vitamin D activation, where Leydig cells could represent key players in this process since they express the highest amount of CYP2R1, a key enzyme involved in vitamin D 25 hydroxylation.

AIM

To evaluate bone status in unilateral orchiectomy and to assess in vivo and in vitro LH-dependency of Vitamin D 25 hydroxylation.

SUBJECTS AND METHODS

125 normotestosteronemic patients with testicular cancer (TC), featured by unilateral orchiectomy and 41 age-matched healthy male controls were studied in the Center for Human Reproduction Pathology at the University of Padova. To evaluate LH-dependency of Vitamin D 25 hydroxylation in vitro, Leydig cell cultures were stimulated with hCG and assessed for CYP2R1 expression, whereas in vivo 10 hypogonadotropic hypogonadal (HH) patients were evaluated before and after treatment with gonadotropins for bone metabolism markers. Hormonal pattern and bone metabolism markers were measured in all subjects, whereas 105 patients and 41 controls underwent bone densitometry by DEXA.

RESULTS

In TC patients 25-hydroxyvitamin D levels were significantly lower compared to controls. Furthermore, 23.8% of patients with TC displayed low bone density (Z-score <-2 SD). None of the 41 control subjects showed any significant alteration of BMD. In vitro and in vivo studies revealed that CYP2R1 expression in Leydig cells appeared to be hCG dependent.

CONCLUSION

Our data show an association between TC and alteration of the bone status, despite unvaried androgen and estrogen levels, suggesting the evaluation of bone status and possible vitamin D deficiency in TC survivors.

Trends in oral, pharyngeal and oesophageal cancer mortality in Australia: the comparative importance of tobacco, alcohol and other risk factors

OBJECTIVE

The relationship of long-term population-level trends in oral, pharyngeal and oesophageal cancer mortality with major risk factors such as tobacco consumption have not been statistically analysed in Australia. We have demonstrated the long-term implications using historical data.

METHODS

Estimated age and sex-specific tobacco consumption back-extrapolated to 1887 were used together with alcohol and fruit and vegetable consumption data to examine their association with trends in oral, pharyngeal and oesophageal cancer mortality. Log-linear Poisson regression models were applied to specify the relationship with oesophageal and pharyngeal mortality data.

RESULTS

Oral cancer mortality for males decreased sharply in the first half of the 20th Century in contrast to steadily rising tobacco consumption. Female oral and pharyngeal cancer remained steady at low levels. Post-World War II male and female oesophageal and male pharyngeal cancer mortality rose, then either fell or stabilised, without a clear relationship with risk factors.

CONCLUSIONS

Tobacco and alcohol consumption have influenced post-World War II trends in oral, pharyngeal and oesophageal cancer mortality. However, the challenges in using historical population level data prevent precise interpretation of findings.

IMPLICATIONS

There is increased exposure to risk factors for these cancers in many low- and middle-income countries. In particular, smoking cessation programs are needed to prevent increases in mortality from these cancers in such countries.

Tendência de mortalidade por câncer de colo de útero para o Estado de Minas Gerais, Brasil, 1980-2005

Foi avaliada a tendência da mortalidade por câncer cervical no Estado de Minas Gerais, Brasil, no período compreendido entre 1980-2005. Os dados demográficos e de mortalidade disponíveis na página da Internet do Departamento de Informática do SUS (DATASUS) foram utilizados para estimar a taxa de mortalidade por câncer de colo de útero e útero porção não especificada no local e período considerados. Foi realizada regressão linear, considerando-se a taxa de mortalidade como variável resposta e o ano do diagnóstico como variável explicativa. A mortalidade variou de 9,18/100 mil em 1980 para 5,70/100 mil em 2005. O modelo log-linear revelou redução da mortalidade por câncer cervical de cerca de 1,93% ao ano na região e período avaliados (p = 0,000), sendo tal redução observada principalmente para os casos classificados como câncer de útero porção não especificada. A tendência observada de queda da mortalidade pela doença sugere melhoria no acesso a métodos de diagnóstico e tratamento oportunos e adequados em Minas Gerais nos últimos anos, embora a cobertura do rastreamento ainda seja insatisfatória.

Age-related risk of mortality from bladder cancer in diabetic patients: a 12-year follow-up of a national cohort in Taiwan

BACKGROUND

To compare bladder cancer mortality between diabetic patients and the general population.

MATERIALS AND METHODS

Yearly sex-specific mortality rates for age 25-64, 65-74, and > or =75 years in Taiwanese general population for 1995-2006 were calculated; 113,347 diabetic men and 131,573 diabetic women aged > or =25 years recruited in 1995-1998 were followed prospectively.

RESULTS

In the general population, 4,943 men and 2,291 women died of bladder cancer, and aging was associated with increased risk. Although the trend of crude mortality was increasing in either sex, the trend of age-standardized rates had been steady. The average crude and age-standardized mortality rates were 5.35 and 5.98 (per 100,000 population), respectively, for men; and were 2.63 and 3.02 for women. A total of 224 diabetic men and 126 diabetic women died of bladder cancer with crude mortality of 26.0 and 11.9 per 100,000 person-years, respectively. The relative risk of bladder cancer mortality (95% confidence interval) for diabetic patients was 2.18 (1.75-2.72), 2.50 (2.06-3.04), and 5.95 (4.57-7.74), in men, and 1.34 (0.96-1.89), 2.48 (1.92-3.19), and 7.44 (5.46-10.15), in women, for ages > or =75, 65-74, and 25-64 years, respectively.

CONCLUSIONS

Diabetic patients had a higher risk of bladder cancer mortality, which is more remarkable in the younger population.

Sperm nuclear apoptotic DNA fragmentation in men with testicular cancer

OBJECTIVE

To verify whether sperm from patients with a seminoma and patients with a non-seminoma present with an increased rate of apoptotic DNA fragmentation, when compared with men without testicular cancer and who had fathered a child in the 2 years preceding the study.

DESIGN

Controlled prospective study.

SETTING

Patients referred to a sperm bank in an academic research environment.

PATIENT(S)

Men with a diagnosed seminoma, men with a diagnosed non-seminoma, both after orchiectomy and before adjuvant therapy, and men with proven paternity in the 2 previous years.

MAIN OUTCOME MEASURE(S)

Rate of nuclear apoptotic sperm DNA fragmentation as assessed by TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) assay, classified as positive (with DNA fragmentation) or negative (without DNA fragmentation).

RESULT(S)

Of the 48 men with testicular cancer included in the study, 29 (60.4%) presented a non-seminoma and 19 (39.6%) a seminoma. Patients with non-seminoma presented with lower progressive sperm motility than the control group (57.4% and 66.3%, respectively), but both were still within normal ranges. Sperm concentration was lower in seminoma (31.2 x 10(6)/mL) and in non-seminoma (20.6 x 10(6)/mL) when compared with the control group (78.1 x 10(6)/mL), but values did not differ between the two testicular cancer groups. Sperm morphology was lower in patients with non-seminoma than in the control group (10% and 13.1%, respectively). Results for sperm nuclear apoptotic DNA fragmentation (mean; standard deviation) were 12.6%; 4.5% for the control group, 12.2%; 5.5% for the non-seminoma group, and 12.5%; 6.4% for the seminoma group. No differences were found between the three groups.

CONCLUSION(S)

Our results demonstrate that the presence of a seminoma or a non-seminoma is not associated with an increase in sperm apoptotic DNA fragmentation.

International comparisons of survival from lung cancer: pitfalls and warnings

Population-based survival data can provide valuable comparative data on outcome but should be interpreted with caution. Differences in data collection and analysis, patient and tumor characteristics and treatment options can have an impact on reported results. Ideally, data from the whole population, including clinical-only diagnoses, should be reported and the methods of case identification described. The relative survival rates should preferably be given. Data on patient characteristics such as age, sex, ethnicity and socioeconomic deprivation should be described, together with tumor details such as pathology and clinical stage. Whenever possible, details on the use of treatments should be reported.

Forecasting age-specific breast cancer mortality using functional data models

Accurate estimates of future age-specific incidence and mortality are critical for allocation of resources to breast cancer control programmes and evaluation of screening programmes. The purpose of this study is to apply functional data analysis techniques to model age-specific breast cancer mortality time trends, and forecast entire age-specific mortality functions using a state-space approach. We use annual unadjusted breast cancer mortality rates in Australia, from 1921 to 2001 in 5 year age groups (45 to 85+). We use functional data analysis techniques where mortality and incidence are modelled as curves with age as a functional covariate varying by time. Data are smoothed using non-parametric smoothing methods then decomposed (using principal components analysis) to estimate basis functions that represent the functional curve. Period effects from the fitted coefficients are forecast then multiplied by the basis functions, resulting in a forecast mortality curve with prediction intervals. To forecast, we adopt a state-space approach and an automatic modelling framework for selecting among exponential smoothing methods.Overall, breast cancer mortality rates in Australia remained relatively stable from 1960 to the late 1990s, but have declined over the last few years. A set of four basis functions minimized the mean integrated squared forecasting error and account for 99.3 per cent of variation around the mean mortality curve. Twenty year forecasts suggest a continuing decline, but at a slower rate, and stabilizing beyond 2010. Forecasts show a decline in all age groups with the greatest decline in older women. The proposed methods have the potential to incorporate important covariates such as hormone replacement therapy and interventions to represent mammographic screening. This would be particularly useful for evaluating the impact of screening on mortality and incidence from breast cancer.

Testicular Cancer Variations in Time and Space in Europe

OBJECTIVES

Testicular cancer (TC) is the most common malignancy in young men. A review of all published articles on TC incidence revealed an increased incidence in Northern and Central Europe. We extended the analysis to the whole of Europe by using all data available, notably from registries.

METHODS

We performed a PubMed search and selected articles dealing with TC incidence. We obtained additional information from data of European registries through the eight volumes of the Cancer Incidence in Five Continents, IARC Scientific Publications.

RESULTS

Since the Second World War, TC incidence has been increasing in nearly all European countries. It has doubled in several countries, including France, since 1970. We observed that the increase followed a gradient: the highest rate is centred in Denmark and Germany, and decreases progressively in a centrifugal manner.

CONCLUSIONS

TC incidence is increasing throughout Europe, but wide discrepancies exist between the different countries. The reasons for such a phenomenon are still unclear although environmental factors are strongly suspected, which could have an impact on male fertility. From a public health perspective, further research using cases collected through national and regional population-based registers and case-control studies must be strongly encouraged.

Testicular germ-cell cancer

Testicular germ-cell tumours (TGCTs) represent the model of a curable malignancy; sensitive tumour markers, accurate prognostic classification, logical series of management trials, and high cure rates in both seminomas and non-seminomas have enabled a framework of effective cancer therapy. Understanding the molecular biology of TGCT could help improve treatment of other cancers. The typical presentation in young adults means that issues of long-term toxicity become especially important in judging appropriate management. A focus of recent developments has been to tailor aggressiveness of treatment to the severity of the prognosis. Recent changes affect the most common subtypes and include the reduction of chemotherapy for patients who have metastastic non-seminomas and a good prognosis, and alternatives to adjuvant radiotherapy in stage I seminomas. We summarise advances in the understanding and management of TGCT during the past decade.

Bayesian methods for early detection of changes in childhood cancer incidence: Trends for acute lymphoblastic leukaemia are consistent with an infectious aetiology

Published data on time trends in the incidence of childhood leukaemia show inconsistent patterns, with some studies showing increases and others showing relatively stable incidence rates. Data on time trends in childhood cancer incidence from the Childhood Cancer Registry of Piedmont, Italy were analysed using two different approaches: standard Poisson regression and a Bayesian regression approach including an autoregressive component. Our focus was on acute lymphoblastic leukaemia (ALL), since this is hypothesised to have an infectious aetiology, but for purposes of comparison we also conducted similar analyses for selected other childhood cancer sites (acute non-lymphoblastic leukaemia (AnLL), central nervous system (CNS) tumours and neuroblastoma (NB)). The two models fitted the data equally well, but led to different interpretations of the time trends. The first produced ever-increasing rates, while the latter produced non-monotonic patterns, particularly for ALL, which showed evidence of a cyclical pattern. The Bayesian analysis produced findings that are consistent with the hypothesis of an infectious aetiology for ALL, but not for AnLL or for solid tumours (CNS and NB). Although sudden changes in time trends should be interpreted with caution, the results of the Bayesian approach are consistent with current knowledge of the natural history of childhood ALL, including a short latency time and the postulated infectious aetiology of the disease.

Increasing mortality rates of common malignancies in Colombia: an emerging problem

BACKGROUND

As a result of a major social and demographic transition, Colombia is currently undergoing major changes in disease-specific mortality rates, including an increasing burden of cancer death. The current article described some aspects of the evolution of cancer mortality in Colombia and, in particular, highlighted the trends for the most common causes of cancer death in Colombia.

METHODS

Cancer deaths registered in the national mortality database from 1981-1996 were used to obtain age-standardized mortality rates by gender and site using the world standard population. The estimated annual percentage change was obtained by fitting a simple log-linear model to the rates in the last decade of recorded data, to gauge recent and near-future cancer mortality trends.

RESULTS

Between 1987 and 1996, the most common causes of cancer death were gastric carcinoma (17% of all cancer deaths), followed by lung (10.5%), prostate (6.2%), cervical (6%), and colorectal carcinoma (5.4%). There were observed declines in mortality trends noted in both genders for gastric carcinoma. Trends in lung carcinoma appeared to be reaching a plateau among men, but increased among women. There were apparent increases in rates of death from colorectal carcinoma for both genders, and from prostate carcinoma for men. Cervical carcinoma appeared to be increasing moderately.

CONCLUSIONS

The authors reported that mortality rates from the most common malignancies are increasing, indicating that effective strategies for cancer control need to be put into immediate practice. To monitor and evaluate future trends, the provision of high-quality data also needs to be addressed.

Do increases in mortality from intrahepatic cholangiocarcinoma reflect a genuine increase in risk? Insights from cancer registry data in Scotland

The mortality from intrahepatic cholangiocarcinoma has increased recently in England and Wales and elsewhere. This study aims to examine recent trends in the incidence of intrahepatic cholangiocarcinoma in Scotland, to assess the extent to which changes in diagnostic practice may be influencing the observed trends, and to consider whether the results are compatible with a genuine increase in the risk of this cancer. Cancer registration (intrahepatic cholangiocarcinoma and anatomically adjacent cancers) data from Scotland 1968-1997 were analysed, including examination of trends in the percentage of cases recorded as being microscopically-verified. Since the late 1960s, the incidence of intrahepatic cholangiocarcinoma has increased approximately eight-fold in both sexes in Scotland. However, the proportion of cases verified microscopically has decreased substantially since the late 1970s, presumably due to an increasing reliance on radiological imaging for diagnosis. Despite this change in diagnostic practice, the incidence of microscopically-verified intrahepatic cholangiocarcinoma has also increased. While changes in diagnostic practice and misclassification could explain, at least part of, the observed increase in incidence of intrahepatic cholangiocarcinoma, a genuine increase in the risk of this cancer in the Scottish population seems probable. Further work is indicated to examine international trends in incidence, and to assess whether incidence differs within countries according to characteristics such as area of residence, socio-economic status, ethnic origin or occupation.

Increasing incidence of testicular cancer worldwide: a review

PURPOSE

Testicular cancer (TC) is the most common malignancy in 20 to 34-year-old men. Numerous publications have shown an increase in the incidence of testis cancer in the last 40 years with substantial differences among countries. We evaluated worldwide variations in testicular cancer incidence and compared trends in different regions in the world.

MATERIALS AND METHODS

We reviewed 441 studies provided by a MEDLINE search using the key words testis/testicular, cancer/tumor and incidence that were published between 1980 and 2002. From these articles we selected only those devoted to testis cancer incidence and of them only the most recent studies from each country or region. Nevertheless, articles using the same data base but providing new and additional information, for example differences among ethnic groups or controversial explanations for trends, were also retained. We selected 30 articles and analyzed their methodological approach and main results.

RESULTS

Worldwide we observed a clear trend toward an increased TC incidence in the last 30 years in the majority of industrialized countries in North America, Europe and Oceania. Nevertheless, surprising differences in incidence rates were seen between neighboring countries (Finland 2.5/100,000 cases versus Denmark 9.2/100,000) as well as among regions of the same country (2.8 to 7.9/100,000 according to various regional French registers). In addition, substantial differences in the TC incidence and trends were observed among ethnic groups. The increase in the TC incidence was significantly associated with a birth cohort effect in the United States and in European countries. To date except for cryptorchidism no evident TC risk factor has been clearly demonstrated, although the environmental hypothesis with a key role of endocrine disrupters has been put forward by several groups.

CONCLUSIONS

Such a recent increase in the TC rate in most industrialized countries should lead urologists and andrologists to give more attention to testicular cancer symptoms in adolescents and young adults. In a public health perspective further research using cases collected through national and regional population based registers and case-control studies must be strongly encouraged if we wish to be able to assess future trends in TC incidence rates and also identify risk factors.

Increasing incidence of childhood leukemia in Northwest Italy, 1975-98

Although some childhood cancer registries reported increasing incidence, the evidence and magnitude of time trends in the incidence of childhood leukemia are debated and the scientific evidence is conflicting. Only limited data have so far been supplied from Southern European countries. We present an analysis of the incidence trend of childhood leukemia in Piedmont (NW Italy) in 1975-98, based on data from the population-based childhood cancer registry. The Childhood Cancer Registry of Piedmont has been recording cases of childhood neoplasms since 1967. Procedures have been uniform and are based on an active search for cases and relevant information. Only cases with confirmed residence in Piedmont at diagnosis are included. Eight hundred cases of leukemia (622 acute lymphoblastic [ALL], 133 acute nonlymphoblastic [AnLL], 45 other and unspecified) were recorded in the period 1975-98 considered in our study. Incidence trends were analyzed using piecewise regression and Poisson regression, based on annual incidence rates. As results from the 2 analyses were similar, only the former were reported. In the age group 1-4 years, a statistically significant annual 2.6% increase in incidence rate of ALL (adjusted by age and gender; 95% confidence interval [CI] 1.13-4.13) was estimated. There was no evidence of increase in other age groups. During 1980-98, a statistically significant 4.4% annual increase (95% CI 1.86-6.90) was seen for pre-B-All in the age group 1-4 years. An increase was also seen for T-ALL that was not statistically significant. Sensitivity analyses were conducted, with no relevant differences from the main results. Our data suggest an increasing trend in ALL incidence for children between the ages of 1 and 4 years. These results are unlikely to be explained by changes in quality of data or exhaustiveness in reporting in the study period. The results were not changed in the sensitivity analyses we conducted. Possible causes to be investigated include environmental factors, changes in family size and parental age, socioeconomic conditions and geographical distribution of cases.

Trends in the incidence of oral cancer in Nova Scotia from 1983 to 1997

OBJECTIVE

The purpose of the study was to characterize the total burden of oral cancer in Nova Scotia over the 15-year period from 1983 to 1997 and to identify any trends in the number of cases or incidence rates at specific anatomic sites or within specific age or sex groups over this time period.

STUDY DESIGN

All cases that had a diagnosis of invasive oral cancer (ICD-9 sites 140-146) during the study period were retrieved from the records of the Nova Scotia Cancer Registry, which theoretically includes all cancer cases in the province. Cases of in situ carcinoma, lymphoma, and leukemia were not included. All cases during the study period were categorized by tumor site and the age and sex of the patient. Tumors at ICD-9 sites 141 and 143-146 were analyzed separately as intraoral cancer. Trends were studied by grouping cases into three 5-year periods: period 1 (1983-1987), period 2 (1988-1992), and period 3 (1993-1997). Age-standardized incidence rates were calculated to the 1991 Canadian standard population.

RESULTS

A total of 1,155 cases of oral cancer were registered in Nova Scotia for this 15-year study period, accounting for 2.0% of all cancer cases. There was an average of 57 cases in men and 20 cases in women per year. Overall, the most common site was the lip (26% of cases), followed by the tongue (20%), other mouth (16%), tonsil/oropharynx (12%), salivary gland (12%), floor of mouth (10%), and gum (4%). About 5% of cases occurred in patients 40 years and younger, and 53% occurred in patients 65 years and older. Lip cancer in men decreased by 38%, and the age-standardized incidence rate fell from 5.6 to 3.0 per 100,000 from period 1 to period 3. Intraoral cancers in men increased by 23% and the age-standardized incidence rate increased by 10% from period 1 to period 3. Both measures peaked in period 2. Intraoral cancer in women increased steadily by 84%, and the age-standardized incidence rate increased by 48% from period 1 to 3. The male-to-female ratio for intraoral cancer cases decreased from 2.9 to 2.5 to 1.9 over the 3 periods.

CONCLUSION

Although there was a decreasing trend for lip cancer, the number of cases and the age-standardized incidence rate for intraoral cancer increased over the 15-year study period. Intraoral cancer increases in females were dramatic. Trends in the number of cases reflected changing risk and a growing, aging population. More oral cancers occurred each year than cancers of the uterine cervix, suggesting the need for more resource allocation in the areas of research, prevention, and early detection of oral cancer.

'Smoke like a man, die like a man'?: a review of the relationship between gender, sex and lung cancer

Lung cancer is one of the most important 'avoidable' causes of death world-wide. It is also one in which differences in relation to sex and gender are especially significant. Increasing lung cancer deaths amongst women alongside stable or decreasing deaths amongst men in many countries have substantially altered the male:female ratio in this disease and produced a need to understand differences between men and women in lung cancer risk, and how they relate to sex and gender. This paper reviews research on differences between men and women in lung cancer incidence, mortality and survival, focusing on material which adds to our understanding of the complex differences between each group. This review suggests that the risk of lung cancer may be different for men and women in response to a complex interaction between biological factors such as hormonal difference and gendered factors such as smoking behaviour. In particular women's apparently greater relative risk of lung cancer and the differences between men and women in the risk of specific histological types of lung cancer need to be understood from a perspective in which both biological influences and gender influences are drawn out.

Spatial variation and temporal trends of testicular cancer in Great Britain

Increases in testicular cancer incidence have been reported in several countries over a long period. Geographical variability has also been reported in some studies. We have investigated temporal trends and spatial variation of testicular cancer at ages 20-49 in Britain. Temporal trends in testicular cancer incidence were examined, 1974 to 1991 and in mortality, 1981-1997. Spatial variation in incidence was analysed across electoral wards, 1975 to 1991. We used Poisson regression to examine for regional and socio-economic effects and Bayesian mapping techniques to analyse small-area spatial variability. Incidence increased from 6.5 to 11.1 per 100 000 in men at ages 20-34, and from 5.6 to 9.7 per 100 000 in men at ages 35-49, while mortality declined by 50% in both age groups. Risks of testicular cancer varied across regional cancer registries, ranging from 0.79 (95% CI: 0.73-0.84) to 1.32 (95% CI: 1.25-1.38), and was higher in the most affluent compared with the most deprived areas. Analyses within 2 regions (one predominantly urban, the other predominantly rural) did not indicate any localized geographical clustering. The increasing incidence contrasted with a decreasing mortality over time in Great Britain, similar to that found in other countries. The higher risk in more affluent areas is not consistent with findings on social class at the individual level. The absence of any marked geographical variability at small area scale argues against a geographically varying environmental factor operating strongly in the aetiology of testicular cancer.

Changing rates of cancer. The hazards of using a single definition

Changing cancer rates, abstracted from tumor registries, are used to make inferences about the effect of carcinogens and cancer treatments on a population-wide basis. We compared the annual age-standardized incidence rates of extremity soft tissue sarcomas from two large tumor registries using different case definitions. We identified all limb soft tissue sarcoma cases diagnosed 1973-1993 in the Ontario Cancer Registry (OCR) and the Surveillance, Epidemiology, and End Results (SEER) databases. Two case definitions for limb soft tissue sarcoma were used based on missing data, incomplete diagnostic methods and ICD-9 codes; an upper limit estimate of the rates which included all possible cases of limb soft tissue sarcoma and a lower limit estimate of the rates which included all definite cases of limb soft tissue sarcoma (with the true rates lying in between). The upper limit OCR rates showed a statistically significant decreasing linear trend (slope = -0.021, P < 0.01). Whereas the slope of the OCR lower limit regression line showed a statistically significant increase in rates (slope = 0.01, P = 0.04). Neither the upper or lower limit SEER rates had a statistically significant linear trend (slope = 0.002, P = 0.60 and slope = 0.001, P = 0.18, respectively). Case definition affects incidence rates and changing rates of cancer. Thus the use of a single case definition along with changing coding practices may alone explain changing cancer rates.

Patterns of referral, management and survival of patients diagnosed with prostate cancer in Scotland during 1988 and 1993: results of a national, retrospective population-based audit

OBJECTIVES

To examine patterns of referral, management and survival of men with prostate cancer, and to document changes over time.

PATIENTS AND METHODS

All men registered with prostate cancer in 1988 and 1993 were identified from the Scottish Cancer Registry. Data were abstracted according to standard definitions from the available medical records of 930 men in 1988 and 1355 in 1993.

RESULTS

There was limited evidence of multidisciplinary care, with only 8% of patients in 1988 being managed by both a urologist and a clinical oncologist within a year of diagnosis, increasing to 13% in 1993. Only a small proportion of patients were managed by clinical oncologists during the first year of care (14% in 1988 and 20% in 1993). Documentation of thorough staging information was poor, with a T stage being recorded in <30% of cases in both years. Documentation of metastatic status increased from 53% to 63% between 1988 and 1993, paralleling an increase in the use of bone scans. The proportion of cases with pathological grading obtained at diagnosis increased from 63% in 1988 to 68% by 1993. The use of PSA testing and core biopsies increased between the years while the use of transurethral prostatectomy decreased. More patients received radical radiotherapy within a year of diagnosis in 1993 than 1988, increasing from 6% to 9%, and more radical prostatectomies were also undertaken (0.2% to 2.3%). Nonetheless, most patients (81% in 1993) with no documented evidence of metastases received no active intervention (radical radiotherapy, radical prostatectomy, or 'watchful waiting'). The survival at 5 years increased nonsignificantly from 34% for the 1988 cohort to 38% for the 1993 cohort.

CONCLUSION

This audit reveals considerable inconsistency in the management of men with prostate cancer in Scotland. Against a background of controversy about numerous aspects of the management of this disease, the need for a multidisciplinary approach, comprehensive staging and appropriate documentation is highlighted.

beta-casein A1, ischaemic heart disease mortality, and other illnesses

The risk factors identified with cardiovascular disease studied in the WHO MONICA project have been shown to have a limited relationship with the coronary heart disease mortality rates between centres, and in mirroring the historical rise and decline in deaths from the disease. Here we show that correlation of the calculated consumption of the milk protein, beta-casein A1 (excluding milk protein in cheese) against ischaemic heart disease (IHD) mortality has a r2 = 0.86. In the states of the former West Germany, where the breed composition of regional cattle herds has remained virtually constant since the 1950s, IHD mortality by state correlates with the estimated consumption of beta-casein A1. Information on other recognized dietary risk factors does not indicate any significant regional difference. Similarly, the populations of Toulouse in France and Belfast in Northern Ireland have almost identical collective 'traditional' risk factors for heart disease, yet the respective mortality rates vary more than threefold. People from Northern Ireland are estimated to consume 3.23 times more beta-casein A1, excluding cheese, than the French. The remarkable agreement between mortality and the consumption of this allele suggests that this factor is worthy of serious consideration as a potential source of cardiovascular disease when taken in conjunction with regional variations in the traditional risk factors. beta-casein A1 consumption also correlates strongly with type 1 diabetes incidence in 0-14-year-olds, suggesting that IHD and diabetes may share at least one causative risk factor.

Trends in breast cancer mortality in Asturias, Spain

While breast cancer mortality rates are subsiding or beginning to decline in many western countries, in Spain they are increasing. We have studied breast cancer mortality rates in Asturias (Spain) by using the age-period-cohort model for the period of 1975-1994. There was an increase in the adjusted rates. The increase of relative risk of death in the period 1990-1994, in relation to that in 1975-1979, was 43%. There is a tendency for successive cohorts to have higher age-specific rates than previous cohorts. Trends in breast cancer mortality rates have been driven predominantly by birth cohort rate trends over the last decades in Asturias, suggesting that the changes in breast cancer mortality have been largely influenced by changes in aetiological factors.

Ethnicity and oral cancer

Oral squamous-cell carcinoma, the main type of oral cancer, is among the ten most common cancers in the world. The aims of this paper were first, to consider whether there was evidence of marked ethnic variations in the incidence, management, and survival of oral cancer, and then, to review possible explanations for these variations. Evidence from the literature suggests that there is marked, inter-country variation in both the incidence and mortality from oral cancer. There is also growing evidence of intracountry ethnic differences, mostly reported in the UK and USA. These variations among ethnic groups have been attributed mainly to specific risk factors, such as alcohol and tobacco (smoking and smokeless), but dietary factors and the existence of genetic predispositions may also play a part. Variations in access to care services are also an apparent factor. The extent of ethnic differences in oral cancer is masked by the scarcity of information available. Where such data are accessible, there are clear disparities in both incidence and mortality of oral cancer between ethnic groups.

Cancer mortality and exposure to chemical carcinogens in the work place: an ecological study in the Valencian Community, Spain (1981-1995)

To evaluate the geographical distribution of the mortality from malignant tumours in relationship with exposure to chemical carcinogens in the work place, and to asses the possible association between these questions and the percentage of population employed in certain high-risk sectors, an ecological study in the Valencian Community (VC), Spain was carried out. Age-adjusted mortality rates for the total number of malignant tumours, lung, bladder, lymphomas and leukaemia during the periods 1981-1985 and 1991-1995 were calculated for the 34 geographical areas. The percentage of population in each area working in sectors in which they may be exposed to chemical carcinogens was obtained. The relationship between mortality on-the-job exposure was studied using linear regression methods. Large differences in cancer mortality were seen. In men, the geographical pattern was very stable and reveals a significant association with the distribution of certain high-risk jobs. Statistically significant positive correlations (p < 0.001) were found between cancer mortality and the percentage of the population working in metal, wood and furniture sectors. In contrast, a negative and statistically significant (p < 0.001) correlation was observed between cancer mortality and the percentage of the population working in agriculture. In conclusion, although the variability in cancer mortality in men was significantly associated with some occupational sectors in the VC, caution is needed when drawing conclusions about causation from ecological studies.

Rising incidence of prostate cancer in Scotland: increased risk or increased detection?

OBJECTIVE

To assess the extent to which the increasing incidence of prostate cancer in Scotland can be explained by increased detection, particularly through transurethral resection of the prostate (TURP) and use of the prostate-specific antigen (PSA) test. Subjects and methods This population-based study was confined to men resident in Scotland and aged > or =50 years. Temporal trends were examined in age-specific and age-standardized incidence, mortality and TURP rates, and PSA testing rates during 1981-1996. Also analysed were the geographical variations in age-standardized incidence and mortality rates during two distinct periods, 1984-1986 (before PSA testing) and 1994-1996 (after PSA testing). Finally, incidence rates and relative survival at 5 years were calculated by age group and 5-year periods of diagnosis during 1968-1992.

RESULTS

The incidence of prostate cancer in men aged > or = 50 years increased from an age-standardized rate of 142.0 per 100 000 in 1981 to 240.9 in 1996, with the steepest increase occurring between 1992 and 1993. The mortality rate increased similarly until 1993, but was relatively stable thereafter, falling slightly in 1996. In 1981-1988, incidence rates were closely correlated with TURP rates (r = 0.98, P<0.001). In 1989-1996, incidence was closely correlated with PSA testing rates (r = 0.98, P<0.001). By 1994-1996, incidence rates varied substantially between Scottish mainland health boards (range 167.7-303.0 per 100 000), with much less variation in mortality rates (90.7-110.0). Relative survival has increased recently in all age groups although, in the era before PSA testing, survival was reasonably stable despite increasing incidence.

CONCLUSION

Although there may have been a true increase in risk, much of the observed increase in the incidence of prostate cancer in Scotland between 1981 and 1996 has been caused by increased detection, leading recently to considerable variation among different areas of the country. The extent to which this represents the early diagnosis of tumours which would eventually cause symptoms or be life-threatening, or detection of latent disease which would never have become symptomatic, is not clear. There is no evidence so far that the increased incidence is associated with any substantial reduction in mortality.

Incidence of testicular germ-cell malignancies in England and Wales: trends in children compared with adults

The incidence of testicular cancer has been increasing markedly in most industrialised countries. This rise is known to have affected young adults, but it is less clear whether it has affected other age groups, particularly children. We used data from the National Cancer Registry file at the Office of National Statistics (ONS) and the National Registry of Childhood Tumours to examine trends in testicular germ-cell malignancies overall in England and Wales from 1962 to 1990 and in children from 1962 to 1995. The incidence of testicular cancer at all ages rose by 3.4% (95% CI 3.3-3.6%) per annum from 1962 to 1990. A similar rise in the incidence of germ-cell malignancies occurred during the years for which histological information was available in the ONS files, 1971-1989 (3.4%; 3.1-3.6%), to which both seminomas and non-seminomas contributed equally. The incidence of non-seminomas in adults rose in men under age 55 years and declined in older men, whereas there were increases in the incidence of seminomas in both young and older men. Cohort analysis at young ages showed a marked rise in the risk of germ-cell malignancies up to the cohort born in 1955-1959 but no further rise for those born subsequently. The rise in the incidence of these tumours in young adults was paralleled by a similar trend, although less marked, in children aged under 15 years (1.3% per annum; 0.2-2.5%). The increase in risk for children in this very large data set alongside the rise in young adults is compatible with the hypothesis that childhood and adult testicular germ-cell malignancies may have some common risk factors, presumably pre-natal.

Helicobacter pylori infection and gastric cancer: systematic review of the epidemiological studies

BACKGROUND

The published epidemiological studies of chronic Helicobacter pylori infection and gastric cancer yield conflicting results, so there is uncertainty as to whether any material association exists and, if so, how strong it is.

AIM

To review these studies quantitatively.

METHODS

A systematic review of sero-epidemiological studies published before 1998 of H. pylori and gastric cancer, as identified by computer-assisted literature searches of relevant journals, reference lists and discussions with authors. All relevant studies identified were included, subdivided by study design. The following was abstracted from published reports: adjusted odds ratio (or, in prospective studies, the risk ratio) and confidence interval, study design, type of controls, mean age, mean duration of follow-up, assay methods, location of study, and degree of adjustment for confounders.

RESULTS

The 34 retrospective studies included in total 3300 gastric cancers, but their controls were of uncertain validity. The 10 'nested' case-control comparisons in prospective studies included in total only 800 gastric cancers, and combined analysis of them yielded a risk ratio of 2.5 (95% CI: 1.9-3.4; 2P < 0.00001) for gastric cancer in people seropositive for H. pylori antibodies.

CONCLUSIONS

The prospective studies suggest that gastric cancer is 2 or 3 times as common in those chronically infected by H. pylori, but to help investigate causality, further observational studies are still needed, as are large-scale randomized trials of whether antibacterial regimens reduce the eventual incidence of gastric cancer.