Have the recent advancements in cancer therapy and survival benefitted patients of all age groups across the Nordic countries? NORDCAN survival analyses 2002-2021.

BACKGROUND: Since the early 2000s, overall and site-specific cancer survival have improved substantially in the Nordic countries. We evaluated whether the improvements have been similar across countries, major cancer types, and age groups. MATERIAL AND METHODS: Using population-based data from the five Nordic cancer registries recorded in the NORDCAN database, we included a cohort of 1,525,854 men and 1,378,470 women diagnosed with cancer (except non-melanoma skin cancer) during 2002-2021, and followed for death until 2021. We estimated 5-year relative survival (RS) in 5-year calendar periods, and percentage points (pp) differences in 5-year RS from 2002-2006 until 2017-2021. Separate analyses were performed for eight cancer sites (i.e. colorectum, pancreas, lung, breast, cervix uteri, kidney, prostate, and melanoma of skin). RESULTS: Five-year RS improved across nearly all cancer sites in all countries (except Iceland), with absolute differences across age groups ranging from 1 to 21 pp (all cancer sites), 2 to 20 pp (colorectum), -1 to 36 pp (pancreas), 2 to 28 pp (lung), 0 to 9 pp (breast), -11 to 26 pp (cervix uteri), 2 to 44 pp (kidney), -2 to 23 pp (prostate) and -3 to 30 pp (skin melanoma). The oldest patients (80-89 years) exhibited lower survival across all countries and sites, although with varying improvements over time. INTERPRETATION: Nordic cancer patients have generally experienced substantial improvements in cancer survival during the last two decades, including major cancer sites and age groups. Although survival has improved over time, older patients remain at a lower cancer survival compared to younger patients.

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.

Colorectal Cancer Survival in German-Danish Border Regions-A Registry-Based Cohort Study.

The aim of this study was (i) to update the reporting of colorectal cancer survival differences over time in the German-Danish border region (Schleswig-Holstein, Southern Denmark, and Zealand) and (ii) to assess the extent to which it can be explained by stage and primary treatment. Incident invasive colorectal cancer cases diagnosed from 2004 to 2016 with a follow-up of vital status through 31 December 2017 were extracted from cancer registries. Analyses were conducted by anatomical subsite and for four consecutive periods. Kaplan-Meier curves and log-rank tests were computed. Cox regression models using data from Schleswig-Holstein from 2004 to 2007 as the reference category were run while controlling for age, sex, stage, and treatment. The cox regression models showed decreasing hazard ratios of death for all three regions over time for both anatomical subsites. The improvement was stronger in the Danish regions, and adjustment for age, sex, stage, and treatment attenuated the results only slightly. In 2014-2016, colon cancer survival was similar across regions, while rectal cancer survival was significantly superior in the Danish regions. Regional survival differences can only partially be explained by differing stage distribution and treatment and may be linked additionally to healthcare system reforms and screening efforts.

Nordcan.R: a new tool for federated analysis and quality assurance of cancer registry data.

Aim of the article: We present our new GDPR-compliant federated analysis programme (nordcan.R), how it is used to compute statistics for the Nordic cancer statistics web platform NORDCAN, and demonstrate that it works also with non-Nordic data. Materials and methods: We chose R and Stata programming languages for writing nordcan.R. Additionally, the internationally used CRG Tools programme by International Agency for Research on Cancer (IARC/WHO) was employed. A formal assessment of (GDPR-compliant) anonymity of all nordcan.R outputs was performed. In order to demonstrate that nordcan.R also works with non-Nordic data, we used data from the Netherlands Cancer Registry. Results: nordcan.R, publicly available on Github, takes as input cancer and general population data and produces tables of statistics. Each NORDCAN participant runs nordcan.R locally and delivers its results to IARC for publication. According to our anonymity assessment the data can be shared with international organizations, including IARC. nordcan.R incidence results on Norwegian and Dutch data are highly similar to those produced by two other independent methods. Conclusion: nordcan.R produces accurate cancer statistics where all personal and sensitive data are kept within each cancer registry. In the age of strict data protection policies, we have shown that international collaboration in cancer registry research and statistics reporting is achievable with the federated analysis approach. Undertakings similar to NORDCAN should consider using nordcan.R.

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.

Survival of breast cancer patients in German-Danish border regions - A registry-based cohort study.

BACKGROUND AND AIM: Denmark reports slightly lower breast cancer survival before 2010 than its neighbouring country Germany. Previous research is limited by lacking stage and treatment information. This study aims to investigate differences in breast cancer survival between the bordering regions Schleswig-Holstein (Germany), Southern Denmark and Zealand (Denmark) using registry data including stage and treatment information. METHOD: Invasive female breast cancer cases diagnosed during 2004-2013 with follow up through 31st December 2014 were extracted from cancer registries. Cases notified by death certificates only and those aged 90+ years were excluded. Kaplan-Meier curves and log-rank tests were computed. Cox regression analysis was conducted with adjustment for year of diagnosis, age, stage, and treatment. RESULTS: The analytical sample included 42,966 cases. Kaplan-Meier curves and log-rank tests show significant survival differences between the regions. The Cox regression model adjusted for year of diagnosis and age shows significantly worse overall survival of breast cancer patients in both Danish regions compared to Schleswig-Holstein with hazard ratios (HR) of 1.09 (95 % CI: 1.04; 1.15) for patients from Southern Denmark (SD) and 1.25 (95 % CI: 1.18; 1.32) for residents of Zealand (ZL). This effect diminished after adjustment for stage and treatment (HR: 1.05 (SD), 1.09 (ZL) 95 % CI: 0.99; 1.10 (SD), 1.03; 1.15 (ZL)). CONCLUSION: Survival differences can be explained by differing stage distribution and treatment administration, which formerly were more favourable in Schleswig-Holstein. The survival gap will probably close due to Denmark's national screening program and increased use of adjuvant cancer therapy.

The histology of brain tumors for 67 331 children and 671 085 adults diagnosed in 60 countries during 2000-2014: a global, population-based study (CONCORD-3).

BACKGROUND: Global variations in survival for brain tumors are very wide when all histological types are considered together. Appraisal of international differences should be informed by the distribution of histology, but little is known beyond Europe and North America. METHODS: The source for the analysis was the CONCORD database, a program of global surveillance of cancer survival trends, which includes the tumor records of individual patients from more than 300 population-based cancer registries. We considered all patients aged 0-99 years who were diagnosed with a primary brain tumor during 2000-2014, whether malignant or nonmalignant. We presented the histology distribution of these tumors, for patients diagnosed during 2000-2004, 2005-2009, and 2010-2014. RESULTS: Records were submitted from 60 countries on 5 continents, 67 331 for children and 671 085 for adults. After exclusion of irrelevant morphology codes, the final study population comprised 60 783 children and 602 112 adults. Only 59 of 60 countries covered in CONCORD-3 were included because none of the Mexican records were eligible. We defined 12 histology groups for children, and 11 for adults. In children (0-14 years), the proportion of low-grade astrocytomas ranged between 6% and 50%. Medulloblastoma was the most common subtype in countries where low-grade astrocytoma was less commonly reported. In adults (15-99 years), the proportion of glioblastomas varied between 9% and 69%. International comparisons were made difficult by wide differences in the proportion of tumors with unspecified histology, which accounted for up to 52% of diagnoses in children and up to 65% in adults. CONCLUSIONS: To our knowledge, this is the first account of the global histology distribution of brain tumors, in children and adults. Our findings provide insights into the practices and the quality of cancer registration worldwide.

Tobacco-related cancers in Europe: The scale of the epidemic in 2018.

BACKGROUND: Tobacco smoking is the major preventable cause of cancer. Despite the longstanding decline in smoking prevalence, lung cancer remains one of the most frequently diagnosed cancers in both sexes. We aimed to estimate the current cancer burden attributable to smoking in Europe. METHODS: Smoking-related cancer incidence by country, cancer type, sex and age in Europe was estimated from GLOBOCAN 2018. We applied a modified version of the indirect method to estimate the population attributable fraction (PAF) for lung cancer and applied Levin's formula to estimate the PAF for other smoking-related cancer sites. RESULTS: In Europe in 2018, 572,000 and 186,000 cancer cases were attributable to tobacco smoking in males and females respectively, accounting for 28% (males) and 10% (females) of all cancer cases. By region, the largest and the lowest PAF due to smoking in males occurred in Eastern Europe (35% of all cancer cases) and Northern Europe (21%), respectively. Among women, this pattern was reversed (16% in Northern Europe and 6% in Eastern Europe). Lung cancer accounted for more than half of the total cancer burden attributable to smoking (382,000). Other major contributors to the total PAF were lip, oral cavity and pharynx, bladder and laryngeal cancers in men (27% out of total PAF) and colorectal, pancreatic, oral cavity and pharyngeal cancers (21%) in women. CONCLUSIONS: Tobacco smoking was responsible for one in five cancer cases in Europe in 2018. The introduction and robust implementation of tobacco control programmes are critical to reduce this cancer burden in the future.