Estimating multilevel regional variation in excess mortality of cancer patients using integrated nested Laplace approximation.

Models of excess mortality with random effects were used to estimate regional variation in relative or net survival of cancer patients. Statistical inference for these models based on the Markov chain Monte Carlo (MCMC) methods is computationally intensive and, therefore, not feasible for routine analyses of cancer register data. This study assessed the performance of the integrated nested Laplace approximation (INLA) in monitoring regional variation in cancer survival. Poisson regression model of excess mortality including both spatially correlated and unstructured random effects was fitted to the data of patients diagnosed with ovarian and breast cancer in Finland during 1955-2014 with follow up from 1960 through 2014 by using the period approach with five-year calendar time windows. We estimated standard deviations associated with variation (i) between hospital districts and (ii) between municipalities within hospital districts. Posterior estimates based on the INLA approach were compared to those based on the MCMC simulation. The estimates of the variation parameters were similar between the two approaches. Variation within hospital districts dominated in the total variation between municipalities. In 2000-2014, the proportion of the average variation within hospital districts was 68% (95% posterior interval: 35%-93%) and 82% (60%-98%) out of the total variation in ovarian and breast cancer, respectively. In the estimation of regional variation, the INLA approach was accurate, fast, and easy to implement by using the R-INLA package.

Comparing net survival estimators of cancer patients.

The net survival of a patient diagnosed with a given disease is a quantity often interpreted as the hypothetical survival probability in the absence of causes of death other than the disease. In a relative survival framework, net survival summarises the excess mortality that patients experience compared with their relevant reference population. Based on follow-up data from the Finnish Cancer Registry, we derived simulation scenarios that describe survival of patients in eight cancer sites reflecting different excess mortality patterns in order to compare the performance of the classical Ederer II estimator and the new estimator proposed by Pohar Perme et al. At 5 years, the age-standardised Ederer II estimator performed equally well as the Pohar Perme estimator with the exception of melanoma in which the Pohar Perme estimator had a smaller mean squared error (MSE). At 10 and 15 years, the age-standardised Ederer II performed most often better than the Pohar Perme estimator. The unstandardised Ederer II estimator had the largest MSE at 5 years. However, its MSE was often superior to those of the other estimators at 10 and 15 years, especially in sparse data. Both the Pohar Perme and the age-standardised Ederer II estimator are valid for 5-year net survival of cancer patients. For longer-term net survival, our simulation results support the use of the age-standardised Ederer II estimator.

Sensitivity, effect and overdiagnosis in screening for cancers with detectable pre-invasive phase.

Studies on cancer screening often evaluate the performance by indirect indicators. In case the screening detects pre-invasive lesions, they may be a mixture of benefit of sensitivity and effect as well as of harm of overdiagnosis. Here, we develop the formulae for the sensitivity, the effect and overdiagnosis in screening for pre-invasive lesions of cancer. Sensitivity is the ability of screening to identify a progressive lesion at the level of test (relevant for the laboratory), episode (relevant in the clinic) and programme (relevant at the population level). Effect is reduction of cancer incidence in those screened (efficacy) and in the target population (effectiveness). The sensitivity is estimated by interval cancers between two consecutive screens (incidence method) and the effect by interval cancers and cancers detected at the subsequent screen. Overdiagnosis is estimated as the detection rate of pre-invasive lesions minus the rate of invasive cancer prevented by screening in one screening round. All the indicators are corrected for nonattendance and selective attendance by disease risk. The population to be followed and the period of follow-up are defined for each indicator separately. Data on cervix cancer screening with Papnet® automation device are given as an example. Estimation of sensitivity and effect are consistent with the purpose of the screening to prevent invasive disease. We further define the purpose at the level of laboratory, clinical medicine and public health and derive six estimators corresponding to the specific purposes considered in our article.

Chernobyl cleanup workers from Estonia: cohort description and related epidemiological research.

The Estonian study of Chernobyl cleanup workers was one of the first investigations to evaluate the possible health consequences of working in the Chernobyl area (the 30 km exclusion zone and/or adjacent territories) after the 1986 reactor accident. The cohort consists of 4831 men who were dispatched in 1986-1991 for tasks involving decontamination, construction of buildings, transport, radiation measurement, guard duty or other activities. By 31 December 2012, the follow-up of the cohort yielded 102 158 person-years of observation. Exposure and health data were collected by postal questionnaires, biodosimetry evaluations, thyroid screenings, and record-linkages with cancer, causes of death and health insurance reimbursement registers and databases. These data cover socio-demographic factors, employment history, aspects of health behaviour, medical history, work and living conditions in the Chernobyl area, biomarkers of exposure, cancer and non-cancer disease occurrence and causes of death. Cancer incidence data were obtained for 1986-2008, mortality data for 1986-2011 and non-cancer morbidity data for 2004-2012. Although the cohort is relatively small, it has been extensively examined and benefited from comprehensive nationwide population and health registers. The major finding was an increased risk of suicide. Thyroid examinations did not reveal an association with thyroid nodular disease and radiation dose, but did indicate the importance of accounting for screening when making comparisons with unscreened populations. No risk of leukaemia was observed and risks higher than 2.5-fold could be excluded with 95% confidence. Biodosimetry included GPA analyses and chromosomal translocation analyses and indicated that the Estonian cleanup workers experienced a relatively low mean exposure of the order of 0.1 Gy. One value of the Estonian study is in the methodologic processes brought to bear in addressing possible health effects from the Chernobyl accident. Twenty-five years of research are summarised and opportunities for the future listed.

Chernobyl fallout and cancer incidence in Finland.

Twenty-five years have passed since the Chernobyl accident, but its health consequences remain to be well established. Finland was one of the most heavily affected countries by the radioactive fallout outside the former Soviet Union. We analyzed the relation of the estimated external radiation exposure from the fallout to cancer incidence in Finland in 1988-2007. The study cohort comprised all ∼ 3.8 million Finns who had lived in the same dwelling for 12 months following the accident (May 1986-April 1987). Radiation exposure was estimated using data from an extensive mobile dose rate survey. Cancer incidence data were obtained for the cohort divided into four exposure categories (the lowest with the first-year committed dose <0.1 mSv and the highest ≥ 0.5 mSv) allowing for a latency of 5 years for leukemia and thyroid cancer, and 10 years for other cancers. Of the eight predefined cancer sites regarded as radiation-related from earlier studies, only colon cancer among women showed an association with exposure from fallout [excess rate ratio per increment in exposure category 0.06, 95% confidence interval (CI) 0.02-0.11]. No such effect was observed for men, or other cancer sites. Our analysis of a large cohort over two decades did not reveal an increase in cancer incidence following the Chernobyl accident, with the possible exception of colon cancer among women. The largely null findings are consistent with extrapolation from previous studies suggesting that the effect is likely to remain too small to be empirically detectable and of little public health impact.

Coffee consumption and risk of gastric and pancreatic cancer--a prospective cohort study.

Only few prospective studies have examined the association between coffee consumption and risk of gastric and pancreatic cancer. This study is designed to evaluate this relationship among Finns, whose coffee consumption is the highest in the world. A total of 60,041 Finnish men and women who were 26-74 years of age and without history of any cancer at baseline were included in the present analyses. Coffee consumption and other study parameters were determined at baseline using standardized measurements. Participants were prospectively followed up for onset of gastric and/or pancreatic cancer, emigration, death or until June 30, 2006. During a mean follow-up period of 18 years, 299 cases of gastric cancer and 235 cases of pancreatic cancer were found. There was a nonsignificant inverse association between coffee consumption and risk of gastric cancer among men but not in the women. The multivariate-adjusted hazard ratio of stomach and pancreatic cancer incidence for ≥ 10 cups of coffee per day compared with nondrinkers were 0.75 (95% CI, 0.40-1.41) (P for trend = 0.19) and 0.82 (95% CI, 0.38-1.76) (P for trend = 0.95) for the combined population of men and women, respectively. We did not find a significant association between coffee consumption and the risk of gastric and/or pancreatic cancers.

Order of HPV/Chlamydia infections and cervical high-grade precancer risk: a case-cohort study.

Interactions of carcinogenic human papillomaviruses (most notably HPV types 16/18/31/33/45), and HPV6 or Chlamydia trachomatis are not well understood. We have used seroconversions to study effects the order of these infections has on the risk of high-grade cervical precancer. In a cohort of 94,349 Finnish women with paired sera from consecutive pregnancies within an average of 2.4 years, 490 were diagnosed with cervical CIN3/AIS. Serum antibodies to HPV6/16/18/31/33/45 and C. trachomatis were measured in paired sera of the cases and a subcohort of 2,796 women with a minimum of two pregnancies. HPV16-adjusted rate ratios (RR) and confidence intervals were estimated by stratified Cox model. Compared to dual seropositivity already at the first serum sampling, RRs related to HPV6 seropositivity before and after HPV31 seroconversion were 0.4 (95% CI 0.0, 4.4) and 10 (95% CI 1.8, 57). Furthermore, RR related to seroconversions of both HPV18/45 and C.trachomatis between the consecutive pregnancies was 28 (95% CI 4.3, 190). Virtually concomitant HPV18/45 and C.trachomatis infections are associated with very high CIN3 risk.

Breast cancer survival in the US and Europe: a CONCORD high-resolution study.

Breast cancer survival is reportedly higher in the US than in Europe. The first worldwide study (CONCORD) found wide international differences in age-standardized survival. The aim of this study is to explain these survival differences. Population-based data on stage at diagnosis, diagnostic procedures, treatment and follow-up were collected for about 20,000 women diagnosed with breast cancer aged 15-99 years during 1996-98 in 7 US states and 12 European countries. Age-standardized net survival and the excess hazard of death up to 5 years after diagnosis were estimated by jurisdiction (registry, country, European region), age and stage with flexible parametric models. Breast cancers were generally less advanced in the US than in Europe. Stage also varied less between US states than between European jurisdictions. Early, node-negative tumors were more frequent in the US (39%) than in Europe (32%), while locally advanced tumors were twice as frequent in Europe (8%), and metastatic tumors of similar frequency (5-6%). Net survival in Northern, Western and Southern Europe (81-84%) was similar to that in the US (84%), but lower in Eastern Europe (69%). For the first 3 years after diagnosis the mean excess hazard was higher in Eastern Europe than elsewhere: the difference was most marked for women aged 70-99 years, and mainly confined to women with locally advanced or metastatic tumors. Differences in breast cancer survival between Europe and the US in the late 1990s were mainly explained by lower survival in Eastern Europe, where low healthcare expenditure may have constrained the quality of treatment.

Dietary intervention in infancy and later signs of beta-cell autoimmunity.

BACKGROUND: Early exposure to complex dietary proteins may increase the risk of beta-cell autoimmunity and type 1 diabetes in children with genetic susceptibility. We tested the hypothesis that supplementing breast milk with highly hydrolyzed milk formula would decrease the cumulative incidence of diabetes-associated autoantibodies in such children. METHODS: In this double-blind, randomized trial, we assigned 230 infants with HLA-conferred susceptibility to type 1 diabetes and at least one family member with type 1 diabetes to receive either a casein hydrolysate formula or a conventional, cow's-milk-based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. Autoantibodies to insulin, glutamic acid decarboxylase (GAD), the insulinoma-associated 2 molecule (IA-2), and zinc transporter 8 were analyzed with the use of radiobinding assays, and islet-cell antibodies were analyzed with the use of immunofluorescence, during a median observation period of 10 years (mean, 7.5). The children were monitored for incident type 1 diabetes until they were 10 years of age. RESULTS: The unadjusted hazard ratio for positivity for one or more autoantibodies in the casein hydrolysate group, as compared with the control group, was 0.54 (95% confidence interval [CI], 0.29 to 0.95), and the hazard ratio adjusted for an observed difference in the duration of exposure to the study formula was 0.51 (95% CI, 0.28 to 0.91). The unadjusted hazard ratio for positivity for two or more autoantibodies was 0.52 (95% CI, 0.21 to 1.17), and the adjusted hazard ratio was 0.47 (95% CI, 0.19 to 1.07). The rate of reported adverse events was similar in the two groups. CONCLUSIONS: Dietary intervention during infancy appears to have a long-lasting effect on markers of beta-cell autoimmunity--markers that may reflect an autoimmune process leading to type 1 diabetes. (ClinicalTrials.gov number, NCT00570102.).

Chernobyl cleanup workers from Estonia: follow-up for cancer incidence and mortality.

This study examined cancer incidence (1986-2008) and mortality (1986-2011) among the Estonian Chernobyl cleanup workers in comparison with the Estonian male population. The cohort of 4810 men was followed through nationwide population, mortality and cancer registries. Cancer and death risks were measured by standardised incidence ratio (SIR) and standardised mortality ratio (SMR), respectively. Poisson regression was used to analyse the effects of year of arrival, duration of stay and time since return on cancer and death risks. The SIR for all cancers was 1.06 with 95% confidence interval 0.93-1.20 (232 cases). Elevated risks were found for cancers of the pharynx, the oesophagus and the joint category of alcohol-related sites. No clear evidence of an increased risk of thyroid cancer, leukaemia or radiation-related cancer sites combined was apparent. The SMR for all causes of death was 1.02 with 95% confidence interval 0.96-1.08 (1018 deaths). Excess mortality was observed for mouth and pharynx cancer, alcohol-related cancer sites together and suicide. Duration of stay rather than year of arrival was associated with increased mortality. Twenty-six years of follow-up of this cohort indicates no definite health effects attributable to radiation, but the elevated suicide risk has persisted.

Prospective study of human papillomavirus seropositivity and risk of nonmelanoma skin cancer.

Cutaneous human papillomaviruses (HPVs) have been associated with squamous cell carcinoma (SCC) in case-control studies, but there are limited data from prospective studies assessing whether virus exposure predicts risk of future cancer development. Two major biobanks, the Southern Sweden Microbiology Biobank (1971-2003) and the Janus Biobank (1973-2003) in Norway, containing samples from 850,000 donors, were searched for incident skin cancer for up to 30 years using registry linkages. Altogether, 2,623 donors with samples taken before diagnosis of SCC or basal cell carcinoma (BCC) of the skin were identified. Prediagnostic samples and samples from 2,623 matched controls were tested for antibodies against 33 types of HPV. Baseline seropositivity to HPV types in genus ß species 2 was associated with SCC risk (odds ratio = 1.3, 95% confidence interval: 1.1, 1.7); this was also the case for samples taken more than 18 years before diagnosis (odds ratio = 1.8, 95% confidence interval: 1.1, 2.8). Type-specific persistent seropositivity entailed elevated point estimates for SCC risk for 29 HPV types and decreased point estimates for only 3 types. After multiple hypothesis adjustment, HPV 76 was significantly associated with SCC risk and HPV 9 with BCC risk. In summary, seropositivity for certain HPV types was associated with an increased risk for future development of SCC and BCC.

Has equity in relative survival improved over time in Finland - a methodological exercise.

BACKGROUND: Population-based relative survival is widely used as a method of monitoring the success of cancer control. This success may not be relevant only for an entire country but also regional developments over time are of interest. It would not only be important that the relative survival improved but also that the differences between regions decreased over time. METHODS: In this paper the authors show how relative survival methods can be used to study such differences. In addition to standard methods, some more recently introduced approaches are used, most notably a method for checking the goodness of fit of the relative survival model. This gives confidence in the obtained results and provides additional insight when assumptions are not met. RESULTS: An analysis of cancers of the colon and ovary by cancer control region in Finland in 1953-2003 shows an overall improvement in relative survival, accompanied in colon cancer also by a decrease of differences in relative survival between the regions. Thus, the desired course was observed in colon cancer but not in cancer of the ovary. CONCLUSIONS: These results, applied to further sites, should lead to investigation of differences in cancer control policies between regions.

Future lung cancer incidence in Poland and Finland based on forecasts on hypothetical changes in smoking habits.

OBJECTIVE: the aim is to estimate the future lung cancer incidence in Poland and Finland based on forecasts on hypothetical changes in smoking habits. MATERIAL AND METHODS: data on population, lung cancer and smoking prevalence come from known sources. The simulation model utilized for forecasting was based on smoothing the smoking habit - specific risk ratios estimated for males and females in Europe. RESULTS: depending on the analyzed scenario in 2030 in Poland mortality rates among men would range from 8 to 125/10(5) and among women from 7 to 47/10(5); in Finland among men 5 to 60/10(5) and among women 4 to 22/10(5). CONCLUSIONS: the results obtained clearly indicate that cutting down on the number of smokers translates directly into a considerable reduction of the lung cancer incidence rate.

Mortality in a long-term follow-up after treatment of CIN.

After treatment of the cervical intraepithelial neoplasia (CIN) cervical cancer incidence remains elevated at least for 20 years. Whether the overall or cervical cancer mortality after treatment of CIN is elevated is unknown. The aim of this study was to determine the long-term survival and cause-specific mortality among women treated for CIN. The study population consisted of 7,104 women treated for CIN between 1974 and 2001 and 35,437 individually matched controls. The follow-up of mortality was based on nationwide registries and closed at death, emigration or December 31, 2005. The possible differences in mortality were assessed using Cox proportional hazard model. With follow-up time of approximately 630,000 woman-years, overall 2,781 deaths were observed, 530 among women treated for CIN and 2,251 among reference population (HR 1.1, 95% CI 1.0-1.3). Mortality from any cancer (HR 1.4, 95% CI 1.2-1.7), lung cancer (HR 2.7, 95% CI 1.8-4.1) and HPV-related anogenital cancer (HR 3.1, 95% CI 1.1-8.6) was higher among CIN patients, but mortality from cervical cancer was not (HR 1.0, 95% CI 0.3-4.0). Elevated cervical cancer incidence after treatment of CIN, documented earlier, did not predict elevation in cervical cancer mortality. This suggests high effectiveness of CIN management. Most of the excess mortality observed among CIN patients was due to increased risk of other cancers. These long-term mortality patterns should be considered when planning and evaluating the management of CIN lesions and related cervical or other cancer prevention activity.

Cure fraction model with random effects for regional variation in cancer survival.

Assessing regional differences in the survival of cancer patients is important but difficult when separate regions are small or sparsely populated. In this paper, we apply a mixture cure fraction model with random effects to cause-specific survival data of female breast cancer patients collected by the population-based Finnish Cancer Registry. Two sets of random effects were used to capture the regional variation in the cure fraction and in the survival of the non-cured patients, respectively. This hierarchical model was implemented in a Bayesian framework using a Metropolis-within-Gibbs algorithm. To avoid poor mixing of the Markov chain, when the variance of either set of random effects was close to zero, posterior simulations were based on a parameter-expanded model with tailor-made proposal distributions in Metropolis steps. The random effects allowed the fitting of the cure fraction model to the sparse regional data and the estimation of the regional variation in 10-year cause-specific breast cancer survival with a parsimonious number of parameters. Before 1986, the capital of Finland clearly stood out from the rest, but since then all the 21 hospital districts have achieved approximately the same level of survival.

Early introduction of oats associated with decreased risk of persistent asthma and early introduction of fish with decreased risk of allergic rhinitis.

The evidence of the effect of the age at introduction of new foods during infancy on the development of asthma and allergic rhinitis is inconsistent and scarce. We set out to study these associations. A prospective birth cohort of infants with increased HLA-DQB1-conferred risk for type 1 diabetes was recruited in 1996-2000. The families completed at home a record on the age at introduction of new foods. Persistent asthma and allergic rhinitis were assessed at the age of 5 years with an International Study of Asthma and Allergies in Childhood-type questionnaire. The Cox proportional hazards regression analyses were adjusted for parental asthma and allergic diseases, and several perinatal and sociodemographical factors. Out of the 1293 children, 77 (6.0 %) developed persistent asthma; and out of the 1288 children, 185 (14.4 %) developed allergic rhinitis by the age of 5 years. Early age at introduction of oats was associated with a reduced risk of persistent asthma (hazard ratio (HR; 95 % CI) for the first and mid-tertiles compared with the latest tertile was 0.36 (0.15, 0.85) and 0.37 (0.22, 0.62), respectively, P < 0.001). Early age at introduction of fish was dose dependently associated with a decreased risk of allergic rhinitis (HR (95 % CI) for the first and mid-tertiles compared with the latest tertile was 0.34 (0.22, 0.54) and 0.45 (0.28, 0.70), respectively, P < 0.001). The present finding that age at introduction of oats is inversely and independently associated with development of persistent asthma is novel. We confirmed the earlier observation that the age at introduction of fish is inversely related to the risk of allergic rhinitis. Clinical implications remain to be determined.

Trends in the survival of patients diagnosed with cancer in the Nordic countries 1964-2003 followed up to the end of 2006. Material and methods.

UNLABELLED: Comparable data on cancer incidence and mortality in Denmark, Finland, Iceland, Norway, and Sweden are available for analysis through a collaboration of the national Cancer Registries via the NORDCAN website (http://ancr.nu). In the continued spirit of Nordic collaborative research, a number of studies examining trends in cancer survival are published in this journal. MATERIAL AND METHODS: The data were divided into eight 5-year periods by sex in five Nordic countries. Age-standardised 5-year relative survival ratios and excess mortality rates in the short-term (first month and 1-3 months following diagnosis), and the long-term (2-5 years after diagnosis) were calculated, as were age-specific 5-year relative survival using cohort-survival methods. A hybrid method combining the cohort and period methods was used for the period 1999-2003 as not all patients were followed for five years. Age-standardisation used the International Cancer Survival Standard, and calculation of expected deaths used country-specific population mortality rates. RESULTS: The data series constitutes 3 360 397 tumours among 3 160 802 patients followed up for death through 2006 for 39 different cancer sites diagnosed in the years 1964-2003. The paper describes the data, exclusions and imputations, design and analysis, age structure and standardisation procedures, follow-up, and case-mix adjustment methods. CONCLUSION: The strengths of this study include the overall comparability and quality of the data, the national coverage, and the length of the time series. Collecting and analysing data from the five Nordic countries for 39 different cancer sites over 40 years in a systematised and comparable way is a major undertaking. A thorough description of the analyses, definitions and exclusions in the survival study, supplemented with corresponding information on cancer incidence and mortality is needed for appropriate interpretation and comparison between countries, and between and within cancer sites. This information must be made available to provide appropriate interpretation of the site-specific results.

Trends in the survival of patients diagnosed with breast cancer in the Nordic countries 1964-2003 followed up to the end of 2006.

BACKGROUND: Breast cancer is the leading cancer among women worldwide in terms of both incidence and mortality. European patients have generally high 5-year relative survival ratios, and the Nordic countries, except for Denmark, have ratios among the highest. MATERIAL AND METHODS: Based on the NORDCAN database we present trends in age-standardised incidence and mortality rates of invasive breast cancer in the Nordic countries, alongside 5- and 10-year relative survival for the period of diagnosis 1964-2003 followed up to the end of 2006. Excess mortality rates are also provided for varying follow-up intervals after diagnosis. The analysis is confined to invasive breast cancer in Nordic women. RESULTS: Incidence increased rapidly in all five countries, whereas mortality remained almost unchanged. Both incidence and mortality rates were highest in Denmark. Between 1964 and 2003 both 5- and 10-year relative survival increased by 20-30 percentage points in all countries, and 10-year survival remained around 10 percentage points lower than 5-year survival. Relative survival was lowest in Denmark throughout the period, with a 5-year survival of 79% for years 1999-2003, but 83-87% in the other countries. From 1964 the youngest women had the highest survival ratios up until the introduction of screening, when a shift occurred towards higher survival among age groups 50-59 and 60-69 in each country, except for Denmark. Excess death rates during the first months after diagnosis were highest in Denmark. CONCLUSION: Breast cancer survival is high and rising in the Nordic countries, and probably relates to the early implementation of organised mammography screening in each country except Denmark and a high and relatively uniform standard of living, diagnosis and treatment. Denmark stands out with higher mortality and poorer survival. The major determinants may include a failure to instigate national breast screening and a greater co-morbidity resulting from a higher prevalence of both tobacco smoking and alcohol consumption.

Survival of patients diagnosed with cancer in the Nordic countries up to 1999-2003 followed to the end of 2006. A critical overview of the results.

UNLABELLED: Differences in Nordic cancer patient survival observed today originate from the 1970s, but were first identified in a mortality prediction from 1995. This paper provides timely comparisons of survival using NORDCAN, a database with comparable information from the Nordic cancer registries. Elucidation of the differences is important when monitoring cancer care generally and evaluating the impact of cancer plans. MATERIAL AND METHODS: The NORDCAN database 1964-2003 with follow-up for death through 2006, was used to analyse incidence, mortality, and survival for all NORDCAN cancer sites. We analysed 5-year relative survival and excess mortality rates in the first three months and 2-5 years after diagnosis. RESULTS: The time trends in survival 1989-2003 were largely similar between the Nordic countries with increases in 14 sites among men and 16 among women. In all countries the excess mortality rates were highest in the first three months after diagnosis, but decreased to similar levels across all countries 2-5 years after diagnosis. Comparing countries excess mortality was highest in Denmark irrespective of follow-up period. Lower survival was observed for Danish cancer patients in 23 of the 33 cancer sites in men and 26 of 35 sites in women. Low and similar levels of survival were observed for cancers of the oesophagus, lung, liver and pancreas, while an 8-10 percentage point difference in survival was found between countries for colorectal cancer. CONCLUSION: The notable differences in Nordic cancer patient survival can be linked to national variations in risk factors, co-morbidity, and the implementation of screening. Improved treatment and primary prevention, in particular the targeting of tobacco and alcohol use, is required to improve cancer control. The recently-initiated cancer plans in Denmark and Norway are yet to show an observable effect on the corresponding cancer survival.

Trends in survival of patients diagnosed with cancer of the digestive organs in the Nordic countries 1964-2003 followed up to the end of 2006.

UNLABELLED: Cancers of the digestive organs (including the oesophagus, stomach, small intestine, colon, rectum and anus, liver, gallbladder, and pancreas) constitute one-fifth of all cancer cases in the Nordic countries and is a group of diseases with diverse time trends and varying consequences for public health. In this study we examine trends in relative survival in relation to the corresponding incidence and mortality rates in the Nordic countries during the period 1964-2003. MATERIAL AND METHODS: Data were retrieved from the NORDCAN database for the period 1964 to 2003, grouped into eight 5-year periods of diagnosis. The patients were followed up until the end of 2006. Analysis comprised trends in 5-year relative survival, excess mortality and age-specific relative survival. RESULTS: Survival following cancers of the colon and rectum has increased continuously over the observed period, yet Danish patients fall behind those in the other Nordic countries. The largest inter-country variation is seen for the rare cancers in the small intestine. There has been little increase in prognosis for patients diagnosed with cancers of the liver, gallbladder or pancreas; 5-year survival is generally below 15%. Survival also remains consistently low for patients with oesophageal cancer, while minor increases in survival are seen among stomach cancer patients in all countries except Denmark. The concomitant incidence and mortality rates of stomach cancer have steadily decreased in each Nordic country at least since 1964. CONCLUSION: While the site-specific variations in mortality and survival largely reflect the extent of changing and improving diagnostic and clinical practices, the incidence trends highlight the importance of risk factor modification. Alongside the ongoing clinical advances, effective primary prevention measures, including the control of alcohol and tobacco consumption as well as changing dietary pattern, will reduce the incidence and mortality burden of digestive cancers in the Nordic countries.