Age-specific Cancer Mortality Research Articles

Cancer surveillance using registry data: Results and recommendations for the Lithuanian national prostate cancer early detection programme

IntroductionWe describe long term trends in prostate cancer epidemiology in Lithuania, where a national prostate specific antigen (PSA) test based early detection programme has been running since 2006. MethodsWe used population-based cancer registry data, supplemented by information on PSA testing, life expectancy and mortality from Lithuania to examine age-specific prostate cancer incidence, mortality and survival trends among men aged 40+ between 1978 and 2009, as well as life expectancy of screening-eligible men, and the proportion of men with a first PSA test per year since the programme started. ResultsThe number of prostate cancer patients rose from 2.237 in 1990–1994 to 15.294 in 2005–2009. By 2010, around 70% of the eligible population was tested, on average around two times. The early detection programme brought about the highest prostate cancer incidence peaks ever seen in a country to date. Recent incidence and survival rises in the age groups 75–84 suggest PSA testing in the elderly non-eligible population. Life expectancy of men aged 70–74 indicates that less than 30% of patients will live for 15years and may have a chance to benefit from early detection. ConclusionsEarly detection among men aged 70–74, and particularly among the elderly (75+) may have to be reconsidered. Life expectancy assessment before testing, avoiding a second test among men with low PSA values and increasing the threshold for further evaluation and the screening interval may help reducing harm. Publishing information on treatment modalities, side-effects and patient reported quality of life is recommended.

Forecasting Age-Specific Brain Cancer Mortality Rates Using Functional Data Analysis Models

Incidence and mortality rates are considered as a guideline for planning public health strategies and allocating resources. We apply functional data analysis techniques to model age-specific brain cancer mortality trend and forecast entire age-specific functions using exponential smoothing state-space models. The age-specific mortality curves are decomposed using principal component analysis and fit functional time series model with basis functions. Nonparametric smoothing methods are used to mitigate the existing randomness in the observed data. We use functional time series model on age-specific brain cancer mortality rates and forecast mortality curves with prediction intervals using exponential smoothing state-space model. We also present a disparity of brain cancer mortality rates among the age groups together with the rate of change of mortality rates. The data were obtained from the Surveillance, Epidemiology and End Results (SEER) program of the United States. The brain cancer mortality rates, classified under International Classification Disease code ICD-O-3, were extracted from SEER*Stat software.

Projection of Burden of Cancer Mortality for India, 2011-2026

Projection of load of cancer mortality helps in quantifying the burden of cancer and is essential for planning cancer control activities. As per our knowledge, there have not been many attempts to project the cancer mortality burden at the country level in India mainly due to lack of data on cancer mortality at the national and state level. This is an attempt to understand the magnitude of cancer mortality problem for the various calendar years from 2011 to 2026 at 5-yearly intervals. Age, sex and site-wise specific cancer mortality data along with populations covered by the registries were obtained from the report of National Cancer Registry Programme published by Indian Council of Medical Research for the period 2001-2004. Pooled age sex specific cancer mortality rates were obtained by taking weighted average of these six registries with respective registry populations as weights. The pooled mortality rates were assumed to represent the country's mortality rates. Populations of the country according to age and sex exposed to the risk of cancer mortality in different calendar years were obtained from the report of Registrar General of India providing population projections for the country for the years from 2011 to 2026. Population forecasts were combined with the pooled mortality rates to estimate the projected number of cancer mortality cases by age, sex and site of cancer at various 5-yearly periods Viz. 2011, 2016, 2021 and 2026. The projections were carried out for the various cancer-leading sites as well as for 'all sites' of cancer. The results revealed that an estimated 0.44 million died due to cancer during the year 2011, while 0.51 million and 0.60 million persons are likely to die from cancer in 2016 and 2021. In the year 2011 male mortality was estimated to be 0.23 million and female mortality to be 0.20 million. The estimated cancer mortality would increase to 0.70 million by the year 2026 as a result of change in size and composition of population. In males increase will be to 0.38 millions and in females to 0.32 millions. Among women, cancer of the breast, cervical and ovary account for 34 percent of all cancer deaths. The leading sites of cancer mortality in males are lung, oesophagus, prostrate and stomach. The above results show a need for commitment for tackling cancer by reducing risk factors and strengthening the existing screening and treatment facilities.

PCN13 Analysis of the Impact of Prophylactic Vaccination Against Human Papillomavirus Infection Using a Dynamic-Modelling Approach

OBJECTIVES: Since 2008, teenage girls are being vaccinated against Human Papillomavirus (HPV) in Europe. The vaccine coverage did not reach high uptake. The aim of this study is to design a dynamic transmission framework to model HPVtransmission in the population in order to predict epidemiologic and economic consequences of population-based HPV vaccination programs. METHODS: A dynamic transmission model was designed including 7 different HPV-types to predict the epidemiologic and economic consequences of HPV-vaccination. Dutch agespecific HPV-prevalence and cervical cancer incidence and mortality data were used to calibrate the model assuming a steady state. The consequence of HPVvaccination was analyzed in different scenarios. In particular, the age of the vaccinee, inclusion of boys, and a reduced screening compliance was assessed. In sensitivity analyses, the vaccination coverage, duration of vaccine-induced protection, and vaccine choice was varied. RESULTS: Vaccination of 50% of girls against HPV infection results in a 56% overall reduction in cervical cancer incidence. The model predicted outcomes are highly sensitive for the duration of vaccine-induced protection and the vaccination coverage. If vaccination will only provide 20-years of protection a 32% reduction in cervical cancer incidence was observed. HPV16 and 18 will be eradicated from the general population if vaccine coverage is >90%. Vaccination at an older age still provides a relevant number of cases averted however vaccination before sexual debut remains most efficient. Vaccination of boys was found to be not an effective alternative. CONCLUSIONS: HPV vaccination was found to be highly effective in reducing the burden of cervical cancer. The model predicted outcomes are most sensitive for vaccine-induced duration of protection. Vaccination of girls at an older age can be considered to further reduce the incidence of cervical cancer.

LUNG CANCER MORTALITY RISK AMONG AN OCCUPATIONAL COHORT EXPOSED TO A MIXTURE OF COMMERCIAL AND NON-COMMERCIAL AMPHIBOLE ASBESTOS FROM VERMICULITE MINING OPERATIONS IN LIBBY, MONTANA

Background and Aims: Vermiculite mining and milling in Libby, MT supplied the majority of North American demand for vermiculite during the 20th century. Libby vermiculite is contaminated with amphibole asbestos, including, winchite, richterite and tremolite. Libby workers and residents in the community were exposed to this mixture of largely non-commercial asbestos fibers for decades. Several million homes in North America may have vermiculite attic insulation from the Libby, MT mine. Methods: Our analysis is based on 880 workers hired after 1959 when fiber concentrations were lower and possibly more consistent with potential environmental exposure. We used Cox proportional hazards models with time-dependent covariates to assess the effects of Libby amphibole asbestos on lung cancer mortality. Multiple exposure metrics including cumulative exposure, residency-time weighted exposure, and metrics mathematically allowing for effects of fiber clearance or translocation were evaluated. We compared lung cancer potency results using slopes and their corresponding risks with the slopes and risks from other investigations of the Libby worker cohort. Results: There are four researchers who have recently published lung cancer potency results for the Libby amphibole asbestos worker cohort: Sullivan (2007), Berman and Crump (2008), Larson et al. (2010) and Moolgavkar et al. (2010). The adjusted lung cancer mortality slopes per calendar year from these four studies ranged from 1.6x10E-3 to 4.2 x10E-3 per fiber/cc-year. Risks derived through life tables based on age-specific cancer mortality rates from these four studies ranged from 0.01 to 0.08 per fiber/cc. Uncertainties in the application of these epidemiologic data are discussed. Conclusions: Libby amphibole asbestos, a mixture composed primarily of non-commercial amphibole asbestos, has repeatedly been shown to be associated with lung cancer mortality by different investigators using varying definitions of this occupational cohort. Disclaimer: This abstract does not necessarily reflect EPA policy.

Prostate cancer mortality in Taiwanese men: Increasing age-standardized trend in general population and increased risk in diabetic men

Background. To evaluate the trend of prostate cancer mortality in Taiwanese general population and the association between diabetes and prostate cancer mortality.Materials and methods. In the general population during 1995–2006, the trends of prostate cancer mortality were evaluated, followed by calculation of age-specific mortality rates for age 40–64, 65–74, and ≥ 75 years. A cohort of 102,651 diabetic men aged ≥ 40 years recruited in 1995–1998 was followed prospectively.Results. The trends of crude and age-standardized mortality from prostate cancer in the general population increased significantly (P < 0.0001). In the general population, 7,966 men aged ≥ 40 years died of prostate cancer, and aging was associated with increased risk. Age-specific prostate cancer mortality suggested significantly increasing trend for ages 65–74 and ≥ 75 years. A total of 321 diabetic men died of prostate cancer (crude mortality rate 41.9/100,000 person-years). Mortality rate ratios (95% confidence interval) showed higher risk of prostate cancer mortality in the diabetic patients, with magnitude increased with decreasing age: 1.55 (1.29–1.86), 2.68 (2.29–3.13), and 6.84 (5.34–8.75) for age ≥ 75, 65–74, and 40–64 years, respectively.Conclusions. Prostate cancer mortality in the Taiwanese general population is increasing. Diabetic patients have a higher risk of prostate cancer mortality, which is more remarkable with decreasing age.

Poor Progress in Breast Cancer Control in the Elderly in the UK.

Abstract Background:In 1998 England introduced a national cancer target, to reduce cancer mortality in the under 75 year olds from 1996 to 2010 by 20%. This might potentially lead to inequalities between younger and elderly cancer patients. In this study we assessed progress in breast cancer control in the elderly in the UK by comparing cancer mortality rates in the elderly with younger age groups in the UK and by comparing the elderly in the UK with other similar countries.Material and Methods:Mortality data for the UK, USA, Northern Europe (Denmark, Finland, Iceland, Sweden and Norway) and Western Europe (Germany, Netherlands, Luxembourg, Austria, France Switzerland) was obtained from the WHO mortality database. Age specific cancer mortality rates for the age bands 55-64, 65-74, 75-84 and 85 plus were calculated for the different geographies for the three year periods 1995-97 and 2003-05. Change in the differences between the age bands was assessed as the ratio between the youngest age group 55-64, which was set to 1, and the older age groups. The number of excess deaths in the UK was calculated by applying the lowest rate observed in each age band to the UK population, assuming that the UK could achieve the same rate.Results:Compared to other countries the UK had the highest breast cancer mortality rates in all age bands in 1995-07 and 2003-05 and rates were statistically significantly higher in 2003-05 at the 95% Confidence interval limit. In the younger age groups (55-64 and 65-74) the UK had the biggest decrease from 1995-97 to 2003-05 and is decreasing the gap to the other countries. In contrast the UK was the only geography with an increase in mortality rates in the over 85 year olds and only ranked second after the USA in the 75 to 84 year olds. If the UK had the same mortality rates as the lowest observed in each age band 681 breast cancer deaths could be prevented in the 55 to 74 year olds and 1590 in the over 75 year olds each year. The UK also had the greatest increase in the ratio between the 55-64 year olds and 85plus year olds, with and increase of a 100% from 3.5 to 4.5 from 1995-97 to 2003-05. The USA had the lowest rates in each age group.Conclusion:Little progress has been made in decreasing breast cancer mortality rates in the elderly in the UK. The gap in breast cancer mortality in the elderly compared to the younger age groups as well as the other countries is increasing. The gap with other countries will be closed only if there is a marked decrease in death rates in the over 75s. Future analysis should also look at the causes of higher mortality in the UK, taking the USA as the gold standard. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2059.

The Decline in U.S. Cancer Mortality in People Born since 1925

The conventional practice of analyzing overall age-adjusted cancer mortality rates heavily emphasizes the experience of older, higher mortality age groups. This may conceal shifts in lifetime cancer mortality experience emerging first in younger age groups. We examined age-specific cancer mortality rates and birth cohort-specific cancer mortality rates in U.S. mortality data recorded since 1955 to assess the effects of age, period, and cohort in secular mortality trends. Cancer mortality and population data were obtained from WHO Statistical Information System. Age-specific cancer mortality rates have been steadily declining in the United States since the early 1950s, beginning with children and young adults and now including all age groups. During the second half of the 20th century, each successive decade of births from 1925 to 1995 experienced a lower risk of cancer death than its predecessor at virtually every age for which such a comparison can be made. A major decline in cancer mortality has been occurring in the United States for the past 50 years, affecting birth cohorts born as long as 80 years ago. Excepting lung cancer, much of this decline has occurred despite relatively stable cancer incidence. These findings suggest that improvements in cancer detection, treatment, and/or prevention have reduced the risk of cancer death across the life span for individuals born in the last three quarters of the 20th century.

Five‐year survival after surgical treatment for kidney cancer

Kidney cancer's rising incidence is largely attributable to the increased detection of small renal masses. Although surgery rates have paralleled this incidence trend, mortality continues to rise, calling into question the necessity of surgery for all patients with renal masses. Using a population-based cohort, a competing risk analysis was performed to estimate patient survival after surgery for kidney cancer, as a function of patient age and tumor size at diagnosis. With data from the Surveillance, Epidemiology, and End Results Program (1983-2002), a cohort was assembled of 26,618 patients with surgically treated, local-regional kidney cancer. Patients were sorted into 20 age-tumor size categories and the numbers of patients that were alive, dead from kidney cancer, and dead from other causes were tabulated. Poisson regression models were fitted to obtain estimates of cancer-specific and competing-cause mortality. Age-specific kidney cancer mortality was stable across all size strata but varied inversely with tumor size. Patients with the smallest tumors enjoyed the lowest cancer-specific mortality (5% for masses<or=4 cm). Competing-cause mortality rose with increasing patient age. The estimated 5-year competing-cause mortality for elderly subjects (>or=70 years) was 28.2% (95% confidence interval [CI]: 25.9%-30.8%), irrespective of tumor size. Despite surgical therapy, competing-cause mortality for patients with renal masses rises with increasing patient age. After 5 years, one-third of elderly patients (>or=70 years) will die from other causes, suggesting the need for prospective studies to evaluate the role of active surveillance as an initial therapeutic approach for some small renal masses.

Pancreatic cancer mortality in Egypt: Comparison to the United States pancreatic cancer mortality rates

Objectives: Little is known about the descriptive epidemiology of pancreatic cancer in many developing countries, such as Egypt. It is believed to be rare in developing countries, but this may reflect lack of systematic cancer registration. Mortality may serve as a surrogate for incidence, since the disease is lethal. Because of availability of reliable mortality registration in Egypt, we used the national mortality data to estimate pancreatic cancer mortality in 2765 deaths from 2000 to 2004, and to gain insights into the disease incidence. Methods: Mortality data in Egypt was obtained from the electronic national mortality records of the Ministry of Health. We calculated population-based age-specific and age-standardized pancreatic cancer mortality rates for Egypt, and compared them with the Surveillance, Epidemiology, and End Results (SEER) mortality data of the United States. Results: Comparisons of age-specific mortality demonstrated higher rates in Egypt compared to the United States for subjects under age 20 years (relative risks (RR) of 7.7 and 4.2, for the age groups 0–15 and 15–20, respectively), and significantly higher rates in the United States compared to Egypt for subjects 40 years and older (RR 1.8–80.5 for the age groups of 40–45 to 75+). For the majority of age groups in Egypt and the United States, mortality in males was higher than in females. Analysis of regional distribution of pancreatic cancer mortality in Egypt showed significant variations in rates among provinces ( p < 0.0001) with Northern provinces having average rate that is 2.85 times the rate of Southern provinces. The highest mortality rates were observed in the Nile Delta compared to southern Egypt and the oasis. Conclusions: The findings of this study demonstrate both international and regional variation in pancreatic cancer mortality, and highlight the importance of further investigation to explore the possible factors that may contribute to the observed epidemiological patterns.

Validity of Using Background Leukemia Incidence Rates with Cohort Mortality-Based Potency Estimates to Calculate Excess Lifetime Risk

ABSTRACT Data from occupational cohort mortality studies have been used to derive exposure-response curves and general population excess lifetime cancer risks, given low-level, chronic exposure. Using an actuarial method, mortality-based rate ratios associated with cumulative exposures are applied to age-specific background cancer mortality rates for a theoretical population aged birth to 70 years. In one recent U.S. Environmental Protection Agency health assessment, a mortality-based leukemia relative rate model was used with background leukemia incidence rates, rather than mortality rates, to calculate excess lifetime risk of leukemia incidence. We examined the validity and implications of this novel approach, while considering possible bias if a potential leukemogen did not pose equal risk by cell type. Limited sensitivity analyses were also conducted. Our analyses show that using total leukemia mortality-based potency estimates with background incidence rates will introduce a biased estimate of excess lifetime risk, the direction of which varies by potency and the histological type of leukemia. These biases were somewhat increased on adjustment for possible greater susceptibility of children. For potent carcinogens, the traditional approach provides a reasonable approximation of excess lifetime mortality risk for both the more and less fatal forms of leukemia, even after adjustments for children and is, therefore, to be preferred. Less consistency by leukemia cell type and background rate was observed for flatter exposure-response curves. This evaluation illustrates the importance of carefully examining the impact of methodological changes to calculations of excess lifetime risk before implementation.

Cancer mortality trends in the EU and acceding countries up to 2015

Examination of trends in cancer mortality in Europe over the past 30 years has shown that, after long-term rises, age-standardised mortality from most common cancer sites has fallen in the EU since the late 1980s. This study aimed to examine trends in the age-specific and age-standardised cancer mortality rates and numbers of cancer deaths up to 2020 for all cancers and various specific sites for all 15 EU countries, the 10 acceding countries, Bulgaria and Romania (currently applicant countries, along with Turkey), and Iceland, Norway and Switzerland of the four EEA countries. Mortality rates were modelled as a function of age, calendar period and birth cohort. Birth cohort was calculated as age subtracted from calendar period. As a consequence of the generally decreasing trends in the age-standardised rates, the best estimate is that there will be approximately 1.25 million cancer deaths in 2015, which is almost 130,000 (11%) more deaths than in 2000, but 155,000 (11%) fewer deaths than the 1.4 million projected in 2015 on the basis of demographic changes alone. The increases in the forecast numbers of cancer deaths in 2015 are proportionally larger in males than in females (13% and 10%, respectively) and proportionally larger in the acceding countries than in the current EU member countries (14% and 11%, respectively). Our forecasts are conservative best estimates of future cancer mortality. There is clearly scope for large improvements in survival, and hence reductions in cancer mortality, in some countries, through eliminating these differences using existing knowledge and treatment regimes.

Solid cancer risks from radiation exposure for the Australian population

Estimates are made of the risks to the Australian population as a function of age and gender for mortality or morbidity for all solid cancers after exposure to radiation. Excess relative risk (ERR) and excess absolute risk (EAR) models are used. The model coefficients are re-evaluated for radiation doses expressed as effective dose using data from the Japanese Life Span Study. Life-table methods are used throughout and the risk measures studied are: the risk of exposure related death, RERD and the risk of exposure related cancer, RERC. Australian life-table data and the age-specific cancer incidence and mortality rates of Australian males and females are taken from recent published tables. No dose and dose-rate effectiveness factor is applied. Sources of uncertainty used to calculate the confidence regions for the estimated risks include the statistical uncertainties of the model parameters and of the extrapolation of the risks beyond the period supported by the epidemiological data. Summary values of the risks are reported as averages of those calculated from the ERR and the EAR models. For males, the mortality risks per sievert range from 14% for 0-9 year age group, 7% at 30-39 years and 4% at 50-59 years. Corresponding values for females are 20%, 10% and 6%. Incidence risks are higher: for males the estimates are 32% for the 0-9 year group, 12% at 30-39 and 5% at 50-59. Corresponding values for females are 56%, 20% and 8%. The 90% confidence regions are about +/- 50% of these values. Estimates are given for the risks from CT whole-body scanning or virtual colonoscopy which could be used for cancer screening. If used at 3 year intervals and the effective dose per procedure is 10 mSv, then the RERD for males beginning screening at 40, 50 and 60 years is 0.4%, 0.3% and 0.1%, respectively and for females, 0.6%, 0.4% and 0.2%, respectively. RERD estimates for a 5 year interval between screens are about one-third smaller.

#62-S ecological study of bladder cancer in counties with high levels of arsenic in drinking water

Abstract PURPOSE: Bladder cancer incidence and mortality in US counties were studied to determine the excess risk associated with drinking water with arsenic concentrations above the new USEPA MCL of 10 ppb. METHODS: Rural counties, where the majority of the population obtains drinking water from groundwater with high arsenic concentrations (>10 ppb), were identified from databases compiled by the EPA, state agencies and local water utilities. Age-specific bladder cancer mortality rates for the period 1982 to 1998 were obtained for these 33 ‘exposed’ counties and 105 adjacent ‘unexposed’ rural counties in 11 states. A standardized mortality ratio (SMR) for the aggregate ‘exposed’ population was calculated using reference rates from the aggregate ‘unexposed’ population and compared to SMRs calculated using national and state reference rates. SMRs were also calculated for exposed populations in individual states. Standardized Incidence Ratios (SIRs) were calculated in a similar manner for exposed counties in States included in the National Cancer Institute's Surveillance Epidemiology and End Results cancer registry program. RESULTS: Calculated SMRs and SIRs depended on the choices of exposed and reference populations. Risk of bladder cancer mortality for white males was not elevated for the population drawn from the 33 exposed counties (SMR = 0.93; 95%CI = 0.85, 1.02) or for the exposed population drawn from Utah, irrespective of the reference population. Risks of bladder cancer incidence for exposed populations in New Mexico, however, were slightly elevated compared to unexposed reference populations drawn from adjacent counties within the state (SIR = 1.20; 95%CI = 1.13, 1.26). CONCLUSION: A small but statistically significant excess risk for bladder cancer may be attributed to exposure to arsenic at levels >10 ppb in some populations in New Mexico. Additional analyses to examine potential confounding by ethnicity and smoking prevalence are required. The results demonstrate the potential sensitivity of bladder cancer risks from arsenic exposure on a variety of factors. The study illustrates the potential limitations of ecological studies and risk assessment in US populations exposed to high levels of arsenic in drinking water.

The rise and fall in primary liver cancer mortality in Italy

Primary liver cancer (PLC) is the fifth most common cancer site in the world, and the fourth cause of cancer mortality I-4. Hepatocellular carcinoma accounts for 85 to 90% of cases in most countries, while colangiocarcinoma, hepatoblastoma and angiosarcoma account for a small proportion of cases. Incidence and mortality from PLC have an extremely wide geographic variation, since 80% of cases arise in developing countries, particularly in South East Asia and Sub-S&u-an Africa i 4 Even within Europe, an over lo-fold . variation has been observed in liver cancer mortality 5 6. In the early 1990’s, Italy had the second highest liver cancer mortality rates in males, after Hungary, and the third in females, after Bulgaria and Hungary. For both sexes, the lowest PLC rates were in the UK, Scandinavia and Greece 5-7. Upward trends in incidence and mortality from PLC over the last three decades have been reported not only from Italy 5-7, but also from Japan 8, the UK9 lo France ” and the USA 12. These rises were observed in males and females,‘in blacks and whites in the USA, in younger and elderly populations, indicating that they cannot be totally accounted for by increased diagnosis and certification of the disease. It has been indicated that the increased prevalence of hepatitis C virus (HCV) may, in part, be responsible of upward trends 13-16. Changes in the incidence and mortality from liver cirrhosis may also play a role, since PLC generally arises in the cirrhotic liver I7 lx. Mortality from cirrhosis has, in fact, declined in Italy, as in several other developed countries I9 20, but there are indications that its incidence has increased or, at least, has not shown a comparable decrease thus leading to an increased prevalence of the disease. Improvement in the survival rate of cirrhotic patients, due to reduced alcohol consumption and better cure of complications of the disease, may have increased the likelihood of PLC occurrence in those patients 2 s ‘* 19. In contrast, in several of the developing countries in Asia including Chinese and Indian populations downward trends in liver cancer incidence and mortality have been recorded over the last two decades. This has been related to a decreased prevalence of hepatitis B virus (HBV) infections in these populations 2 I3 16. In the light of the different incidence and mortality from PLC worldwide, we examined trends in age-specific and age-standardized liver cancer mortality in Italy over the period 1970-98. Numbers of death certifications from PLC (International Classification of Diseases, ICD, 9 Revision to 155.0) were derived from official death certifications provided by the Italian National Institute of Statistics (ISTAT) in strata of sex and 5-year age groups. Estimates of the resident population were obtained from the same source. Age-specific (for each five-year age group and calendar period) and agestandardized (on the world standard population) death certification rates were derived from the matrix of certified deaths and resident population 21. Figure 1 shows trends in age-standardized death certification rates in males at all ages and selected age groups. The corresponding trends in females are shown in Figure 2. In males, overall age-standardized mortality from PLC rose from about 3/100,000 in the early 1970’s, to reach 9.2/100,000 in 1994, and decreased thereafter to 6.0 in 1998. In females, overall PLC mortality rates were 22.5/100,000 between 1970 and 1994, but dropped to 1.7 in 1998. The fall between 1996 and 1998 was, therefore, 30% in males and 23% in females. The falls were, if anything, greater in middle age (35 to 64 years, -36% for

Breast cancer in New South Wales in 1972-1995: tumor size and the impact of mammographic screening.

To examine the use of mammographic screening in women in New South Wales (NSW), we measured uptake of initial mammograms and estimated the proportions of breast cancers that were screen detected. To see if mammographic screening has been associated with reductions in advanced breast cancers and mortality from breast cancer, we analyzed trends in age-specific and age-standardized breast cancer incidence and mortality from 1972 to 1995 and tumor size in 1986, 1989, 1992 and April to September 1995. Between 1984 and the end of 1995, an estimated 72% of NSW women in their 50s and 67% in their 60s had had at least 1 mammogram and, in 1995, an estimated 39% of invasive breast cancers in women in these age groups were detected by mammography. Before 1989, breast cancer incidence increased only slightly (+1.3% annually) but then, from 1990 to 1995, increased more rapidly (+3.1% annually). Between 1986 and 1995, rates of small cancers (< 1 cm) increased steeply by 2.7 times in women 40-49 years of age and 5.6 times in women 50-69 years of age. The incidence of large breast cancers (3+ cm), after little apparent change to 1992, fell by 17% in women 40-49 years of age and 20% in those 50-69 years of age to 1995. Breast cancer mortality increased slightly between 1972 and 1989 (+0.5% annually) but then fell (-2.3% annually) from 1990 to 1995. We concluded that breast cancer rates had been influenced in expected directions by the introduction of mammographic screening in women resident in NSW. We expect that recent falls in incidence of larger breast cancers and breast cancer mortality will become steeper as screening coverage increases in the second half of the 1990s.

Breast cancer in New South Wales in 1972–1995: Tumor size and the impact of mammographic screening

To examine the use of mammographic screening in women in New South Wales (NSW), we measured uptake of initial mammograms and estimated the proportions of breast cancers that were screen detected. To see if mammographic screening has been associated with reductions in advanced breast cancers and mortality from breast cancer, we analyzed trends in age-specific and age-standardized breast cancer incidence and mortality from 1972 to 1995 and tumor size in 1986, 1989, 1992 and April to September 1995. Between 1984 and the end of 1995, an estimated 72% of NSW women in their 50s and 67% in their 60s had had at least 1 mammogram and, in 1995, an estimated 39% of invasive breast cancers in women in these age groups were detected by mammography. Before 1989, breast cancer incidence increased only slightly (+1.3% annually) but then, from 1990 to 1995, increased more rapidly (+3.1% annually). Between 1986 and 1995, rates of small cancers (<1 cm) increased steeply by 2.7 times in women 40–49 years of age and 5.6 times in women 50–69 years of age. The incidence of large breast cancers (3+ cm), after little apparent change to 1992, fell by 17% in women 40–49 years of age and 20% in those 50–69 years of age to 1995. Breast cancer mortality increased slightly between 1972 and 1989 (+0.5% annually) but then fell (−2.3% annually) from 1990 to 1995. We concluded that breast cancer rates had been influenced in expected directions by the introduction of mammographic screening in women resident in NSW. We expect that recent falls in incidence of larger breast cancers and breast cancer mortality will become steeper as screening coverage increases in the second half of the 1990s. Int. J. Cancer 81:877–880, 1999. © 1999 Wiley-Liss, Inc.

A hierarchical Bayesian approach to age-specific back-calculation of cancer incidence rates.

We propose a Bayesian hierarchical model to estimate age-specific cancer incidence per year from age-specific cancer mortality. The model is based upon the empirical Bayesian approach of Liao and Brookmeyer (1995) and extends that model by consideration of the dependence on age. The incident cases per year are considered as observations from a discrete-time stochastic process following an autoregressive structure within a Poisson regression model. The model assumes that the survival probability among those with cancer is known. We have investigated the sensitivity of the model to the choice of this distribution and have found that this is the most sensitive part of the model. By comparison the predictions of the model are relatively robust to changes in other key areas, such as the number of years an incident case contributes before death, assumptions about parameter equality for identification and the initial prior distributions. The proposed methodology has been investigated using lung cancer mortality data from Scotland. Parameter estimates were obtained through Markov chain Monte Carlo methods, implemented using BUGS.

Prostate cancer mortality in New Zealand: the past and projections for the future.

Ageing male populations and improved diagnosis of early stage disease have contributed to the increasing incidence of prostate cancer observed in many Western countries. The clinical significance of these diagnosed cancers is, however, currently unclear. The aim of this study is to examine trends over time in prostate cancer mortality as an indicative measure of clinically significant disease during a 29-year period (1965-93) which preceded the extensive use of early cancer diagnostic techniques or radical therapy protocols. Age-specific and age-standardized rates were calculated for each year during the study period, using routinely collected mortality and demographic data. A Poisson regression model was used to describe trends in the age-specific rates over time to predict numbers of prostate cancer deaths and the lifetime risk of death over the next 20 years. Significant annual increases ranging from 1 to 2.6% were found for age-specific prostate cancer mortality rates over the 29-year time period, with the largest increases experienced in the younger age groups at risk. Based on projected population ageing and growth alone, annual numbers of prostate cancer deaths are predicted to increase from 487 in 1993 to 664 by the year 2006 and then to 833 by the year 2016. Continuation of the observed increases in age-specific mortality rates would result in a predicted 797 deaths by the year 2006, while an expected 1115 deaths is calculated for the year 2016. This would correspond with an increase in the lifetime risk of death from prostate cancer from a present 3.7 to 4.5% in 10 years and 6.2% in 20 years. The changing pattern of prostate cancer mortality described in this study is likely to represent a significant increase in the incidence of clinically significant disease. This will have a significant impact on the ageing New Zealand male population, and important implications for the provision of effective treatment and preventive strategies.

Differential survival and natural selection: their impact upon aging and cancer mortality

Evidence for natural selection is often presented from the perspective of evolution. However, evolution is not the purpose of natural selection. Natural selection might also impact upon the manifestation of senescence via differential survival. The relationship between age-specific cancer mortality rates and corresponding age group population size in the USA from 1951 to 1989 for age groups over age 45 was examined. Rising age-specific cancer mortality rates among elderly men were increasingly correlated with growing age group population size with increasing age. This relationship was not observed in women. Since an age-specific rate should be independent of age group population size, this finding suggests that successive cohorts of elderly USA men were not comparable with respect to their susceptibility to cancer mortality. Differential survival, which effects men more than women, and its selective culling effect upon the surviving gene pool in an aging population may account for some of the observed increasing cancer mortality rates among elderly men. If so, evidence of natural selection can also be presented from the perspective of manifestation rates for some disorders associated with senescence.