Do investments in cancer registry databases and tools bring added value? NORDCAN as an example.

BACKGROUND: In the 1990s, the large-scale collaboration Kreftbildet i Norden (KIN) drew attention to the need for timely cancer statistics for cancer control planning in the Nordic countries. Supported by the Nordic Cancer Union (NCU), a web-based version of NORDCAN was continually developed by the Association of Nordic Cancer Registries (ANCR) from 2003, with website support and hosting by the International Agency for Research on Cancer (IARC). Despite empirical evidence of its global reach, the question of whether recurrent investment in NORDCAN brings added value was raised; we sought to formally assess this. METHODS: Scientific value was determined by extracting publications citing NORDCAN from PubMed. We compared the funds allocated to the KIN project and later Nordic studies on cancer predictions and survival, with those allocated to NORDCAN. RESULTS: 96 publications in 43 journals were retrieved. Two publication peaks, in 2010 and in 2016 relate to Nordic cancer survival and Danish age care projects, respectively. Papers citing NORDCAN increased substantially from 4 published in 2017 to the 24 papers in 2022. The integration of survival and prediction projects into NORDCAN reduced the costs of investment to one-quarter of the those required in earlier years, in real terms. DISCUSSION: User statistics and scientific output clearly points to NORDCAN bringing added value given resources expended, even with the additional costs imposed to ensure GDPR compliance. Research funding indicates that the databases and interactive tools are critical as both research and education resources. Nonetheless, a sustainable funding model is needed if NORDCAN is to continue to fulfill its utility in cancer control, health care planning and cancer research.

Non-preventable cases of breast, prostate, lung, and colorectal cancer in 2050 in an elimination scenario of modifiable risk factors.

Most Western countries have increasing number of new cancer cases per year. Cancer incidence is primarily influenced by basically avoidable risk factors and an aging population. Through hypothetical elimination scenarios of multiple major risk factors for cancer, we estimated the number of new cancer cases that are non-preventable in 2050. We compare numbers of new postmenopausal breast, prostate, lung, and colorectal cancer cases in 2021 to projected numbers of new cases in 2050 under prevention scenarios regarding smoking, overweight and obesity, and alcohol consumption: no intervention, 50%, and 100% instant reduction. Cancer incidence data were derived from NORDCAN, and risk factor prevalence data from the Danish National Health Survey. Cancer projections were calculated with the Prevent program. Hypothetical 100% instant elimination of major risk factors for cancer in Denmark in 2022 will result in unchanged numbers of new breast and colorectal cancers in 2050. The number of new prostate cancers will increase by 25% compared to 2021. Unchanged risk factor levels will result in noticeable increase in cancer burden. Increase in life expectancy and age will entail an increase in cancer incidence, despite maximum effect of preventive actions in the population. Our results are important when planning future health care.

Improved survival of Danish cancer patients 2007-2009 compared with earlier periods.

INTRODUCTION: For the majority of cancers, improved long-term survival may be accessed from survival during the first year after diagnosis. A steady improvement in survival was seen both before and after the introduction of cancer control plans in 2000 and 2005. On the basis of data from 2007-2009, we studied the trend in 1-year survival after the introduction of the 2005 plan. MATERIAL AND METHODS: All cancers from 1995-2009 were studied in five 3-year cohorts of incident cases which were followed-up for death to the end of 2010. Age-standardised 1-, 3- and 5-year relative survival was calculated and 1-year survival presented for 2004-2006 and 2007-2009 to allow comparison with our previous publication. RESULTS: The improvement over time in overall 1-year age-standardised relative survival was maintained with a three percentage point increase to 72% for men and 75% for women. Exclusion of prostate and breast cancer from calculations lowered relative survival to 65% and 67%, respectively; but improvement was maintained. Cancer sites which previously enjoyed a high survival saw the least or no improvement as was the case for haematological cancers, except for non-Hodgkin lymphoma in men. The differences in survival between men and women are diminishing, especially for cancers of the digestive tract. CONCLUSION: The improvements over time in survival after introduction of the cancer plans were maintained for non-haematological cancers. The fast-track system for diagnosis and treatment introduced gradually by cancer sites until the end of 2008 along with some centralisation of elective surgery may have narrowed the gap in cancer survival between men and women for digestive tract cancers and may also have improved survival for other cancers, e.g. the sex-specific types and kidney and brain cancers. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

Increased suicide risk among Danish women with non-melanoma skin cancer, 1971-1999.

More suicides than expected (standardized mortality ratio=1.3; 95% confidence interval=1.1-1.6) compared to the population risk were found among Danish women with a diagnosis of non-melanoma skin cancer in the period 1971-1999 but not among men. The increased risk might be associated with a different personality type in this cancer group.

The risk of cancer among patients previously hospitalized for atopic dermatitis.

In treatment of severe atopic dermatitis, drugs with carcinogenic potentials are used to manage the disease. We therefore analyzed whether patients having severe atopic eczema had an increased cancer risk. The study population included all individuals hospitalized in Denmark with a primary diagnosis of atopic dermatitis during 1977-1996. Follow-up was conducted in 1996 in the Danish Cancer Register. A total of 6275 persons were included. Among 2030 adult patients, an increased risk of cancer was observed, standard morbidity ratio (SMR)=1.5 (95% CI: 1.2-1.9). Half the excess cases of cancer was keratinocyte carcinomas of the skin diagnosed within the first 9 y of follow-up, SMR=2.4 (95% CI: 1.4-3.9). For men, SMR=2.7 (95%CI: 1.2-5.4). In conclusion, earlier hospitalized adult atopic dermatitis patients had an increased risk of cancer. Half the excess cases of cancer were keratinocyte carcinomas. This may be a result of a detection bias or due to the carcinogenic potentials of some of the therapies of severe atopic dermatitis.

Cancer in Greenlandic Inuit 1973-1997.

OBJECTIVES: During the second half of the 20th century living conditions of the Inuit populations in the Arctic have undergone major transitions. The objective was to investigate how the cancer pattern was affected by these changes, using data from the Danish Cancer Registry and the Civil Registration System. RESULTS: In the period 1973-1997 total cancer incidence increased by 4% per 5 years for men and 6% per 5 years for women. The incidence of lung, stomach, breast and colon cancer increased in both sexes, whereas the incidence of cervical cancer decreased. CONCLUSIONS: Thus, the overall cancer incidence among Greenlandic Inuit is increasing as a result of increases in several cancers that are common in Western populations. In contrast to global trends, a significant increase in the incidence of stomach cancer in both sexes was observed.

Differences in survival from prostate cancer in Denmark, Iceland and Sweden.

INTRODUCTION: Register-based studies have shown large survival differences among prostate cancer patients in the Nordic countries. The aim of this study was to determine the background of such differences in Denmark, Iceland and Sweden. MATERIAL AND METHODS: Patients with prostate cancer were identified through population-based cancer registers in the three countries. Clinical findings at diagnosis were retrieved from hospital records. In Sweden, clinical information was gathered from regional population-based prostate cancer registers. Country-specific incidence and excess mortality rates were compared, with adjustment for prognostic factors. RESULTS: The relative survival in the cohorts was comparable to that in previous population-based studies. Significant differences in excess mortality rates were found across countries, which diminished or disappeared after adjustment for patient characteristics, i.e. metastatic status, clinical T stage and prostate-specific antigen level. A difference in the proportion of patients with metastatic disease was the main explanation of the differences in survival among countries, while the incidence rates of metastatic cancer were similar. DISCUSSION: Register-based studies of the relative survival of prostate cancer patients are influenced by national differences in clinical presentation at diagnosis. Differences in the proportion of patients with metastatic spread explained most of the difference in relative survival among patients in Denmark, Iceland and Sweden. Future country comparisons of relative survival should include adjustment for differences in patient characteristics, such as stage, prostate-specific antigen level and screening intensity.

[Survival of Danish cancer patients 1995-2006]. / Overlevelse for danske kraeftpatienter 1995-2006.

INTRODUCTION: Improved one- and three-year survival was seen after the initiation of the National Cancer Control Plan in year 2000. Short follow-up and lack of five-year survival called for an update with more data. MATERIAL AND METHODS: All cancers from the period 1995-2006 were studied in four cohorts of three-year incident cases from 1995 to 2006 followed to death or to the end of 2008. Age-standardised one-, three- and five-year relative survival and excess mortality were computed. RESULTS: The improved one- and three-year survival was confirmed. The five-year survival increased from 38% in 1995-1997 to 48% in 2004-2006 for men, but a five percentage point increase is owed to the incidence increase of prostate cancer without changed mortality. In women the increase in survival was from 50% to 55%, i.e. a five percentage point increase. Improved five-year survival was seen for cancers of the oesophagus, colon and rectum, lung, and for haematological cancers; for women, also pancreas, ovary, brain and melanoma, and for men prostate cancer survival improved. DISCUSSION: The improved cancer survival was confirmed and it was also observed at the five-year follow-up. The excess mortality is largely present during the first year of follow-up and is a useful indicator of whether changes in diagnosis and care lead to the desired outcome. Overall survival should be interpreted in the context of major changes in recorded incidence due to the introduction of new diagnostic tools and biomarkers such as prostate-specific antigen, as such measures do not necessarily change mortality. Whether cancer care in Denmark has reached the highest international standard remains to be proven by survival comparison to countries with adequate data for a comparative analysis.

[Cancer survival before and after initiating the Danish Cancer Control plan]. / Kraeftoverlevelse før og efter den danske kraeftplan.

INTRODUCTION: Has there been a visible effect on cancer survival after the launch of the first cancer control plan in year 2000? MATERIAL AND METHODS: All cancers reported 1995-2003 to the Danish Cancer Registry were included. Three cohorts diagnosed 1995-1997, 1998-2000 and 2001-2003 were followed for death until 31 December 2006 and age standardized 1- and 3-year relative survival was calculated by the cohort method. RESULTS: One-year survival increased for men from 59 to 65% and for women from 67 to 70%, and 3-year survival from 44 to 51% and 55 to 59%, respectively. The improved 3-year survival for women was after the launch of the cancer plan, whilst for men it was in the entire observation period. Improvement in 3-year survival for both sexes occurred for colon, rectum and lung cancer, and for bladder and prostate in men and esophagus, breast, ovary and leukemia in women. Worse survival was seen for oral and pharyngeal cancer in women. DISCUSSION: The improved trend in survival has been maintained. The cancer plan may improve survival before onset due to the early implementation of recommendations. Since improvements in surgery presents early, 3-year survival is relevant. The improved survival for colo-rectal, lung, bladder, esophagus and ovarian cancer may be related to the cancer plan. Improvement in breast cancer survival is likely due to screening and the DBCG continued activity, whilst increasing incidence of prostate cancer due to PSA testing is likely to be behind our observation. Longer follow-up and a timely and updated cancer registry are needed to fully assess the impact of the cancer plan.

Cancer in Greenlandic Inuit 1973-1997: a cohort study.

The increasing westernization of the Arctic countries may influence the very particular cancer profile of these populations. Our objective was to investigate the development in cancer incidence from 1973 to 1997 in a large and well-defined Inuit population in Greenland. Greenland is part of the Danish Kingdom, and population statistics covering both countries are available from the same registry resource. Data from the Danish Civil Registration System and from the Danish Cancer Registry were used to calculate age-standardized cancer incidence rates for the periods 1973-1987 and 1988-1997 for persons born in Greenland. Using rates for Denmark, sex-specific standardized incidence ratios (SIRs) for 1988-1997 were calculated. Furthermore, age- and sex-specific incidence rates in the 2 periods were calculated for selected cancers. Total cancer incidence increased from 248.5 to 277.9 per 100,000 person-years in men and from 269.4 to 302.2 per 100,000 person-years in women. The incidence of lung, stomach, breast and colon cancer increased, whereas the incidence of cervical cancer decreased. Compared to the Caucasian population in Denmark, high SIRs were found for cancers of the nasopharynx, salivary gland, esophagus, stomach and cervix and low SIRs for testis, bladder, prostate, breast and hematologic cancers. Overall cancer incidence among Greenlandic Inuit is increasing as a result of increases in several cancers that are common in Western populations. A significant increase in the incidence of stomach cancer in both sexes, which contrasts global trends for this cancer, warrants further investigation.

Does stage at diagnosis explain the difference in survival after breast cancer in Denmark and Sweden?

Breast cancer survival differs 9 percentage points between the neighbouring countries of Denmark and Sweden. The authors' aim was to analyse whether this was caused by early detection in Sweden. The extent of disease and outcome was compared in two population-based breast cancer cohorts in 1983-1989. Breast cancer management was decentralized in Denmark without mammography screening whereas treatment in Sweden was centralized and the population partly screened. Ten- and 15-year relative survival was 15% and 6% higher in Sweden (p<0.001) with corresponding differences in crude and disease-specific survival. Stage distribution was significantly more favourable in the Swedish cohort. In multivariate analysis age, tumour size, extent of axillary surgery, and spread affected survival; however, the impact of region persisted (p<0.001). Reanalysis without screening-detected patients only slightly affected the impact of region. It was concluded that early detection had significant impact on survival but other regional differences might be of importance.