Cancer survival in the Faroe Islands over the last 50 years compared to the other Nordic countries.

As sustained development in cancer treatment protocols have led to improved survival in most areas of the world, surveillance is needed to ensure that small populations follow suit. Our study reports age-standardized relative cancer survival in the Faroe Islands compared to the other Nordic countries. We present 1- and 5-year survival estimates and corresponding 95% confidence intervals for the Faroe Islands and compare them with estimates for the Nordic countries. The data for this article has been obtained through the NORDCAN collaboration (2019 data). Age-standardized relative survival was estimated using shared R codes on individual-level data within each country. Ten-year calendar inclusion periods were used in addition to the usual 5-year calendar periods to include cancer sites with few cases, which is especially beneficial to the smaller populations. The primary findings were that 1- and 5-year survival were consistently lower in the Faroes for the summary group all sites but non-melanoma skin cancer for both women and men. Further, 5-year survival was lower for women with ovarian cancer and men with lung cancer than in other Nordic countries. Previously, breast cancer survival was low in the Faroes but has improved to a comparable level over the last few years. Colorectal cancer survival was relatively high for both sexes. The reported estimates in this article call for further research to investigate the cancers with lower survival and should call for actions to improve the survival of Faroese cancer patients.

Standardized prostate cancer incidence and mortality rates following initial non-malignant biopsy result.

OBJECTIVES: To compare the incidence of subsequent prostate cancer diagnosis and death following an initial non-malignant systematic transrectal ultrasonography (TRUS) biopsy with that in an age- and calendar-year matched population over a 20-year period. SUBJECTS AND METHODS: This population-based analysis compared a cohort of all men with initial non-malignant TRUS biopsy in Denmark between 1995 and 2016 (N = 37 231) with the Danish population matched by age and calendar year, obtained from the NORDCAN 9.1 database. Age- and calendar year-corrected standardized prostate cancer incidence (SIR) and prostate cancer-specific mortality ratios (SMRs) were calculated and heterogeneity among age groups was assessed with the Cochran's Q test. RESULTS: The median time to censoring was 11 years, and 4434 men were followed for more than 15 years. The corrected SIR was 5.2 (95% confidence interval [CI] 5.1-5.4) and the corrected SMR was 0.74 (95% CI 0.67-0.81). Estimates differed among age groups (P < 0.001 for both), with a higher SIR and SMR among younger men. CONCLUSION: Men with non-malignant TRUS biopsy have a much higher incidence of prostate cancer but a risk of prostate cancer death below the population average. This underlines that the oncological risk of cancers missed in the initial TRUS biopsy is low. Accordingly, attempts to increase the sensitivity of initial biopsy are unjustified. Moreover, current follow-up after non-malignant biopsy is likely to be overaggressive, particularly in men over the age of 60 years.

Influence of various assumptions for the individual TNM components on the TNM stage using Nordic cancer registry data.

BACKGROUND: The stage at diagnosis is one of the most important predictors for cancer survival. TNM stage is constructed from T (tumor size), N (nodal spread), and M (distant metastasis) components. In many notifications to cancer registries, TNM information is incomplete with unknown N and/or M. We aimed to evaluate the influence of various assumptions for recoding missing N (NX) and M (MX) as N0 and M0 on the proportion with available TNM stage, stage-distribution, and stage-specific relative survival. MATERIAL AND METHODS: We identified 140,201 patients diagnosed with incident cancer of the colon, rectum, lung, breast, or kidney during 2014-2016 in Denmark, Norway, Sweden, or Iceland. Information on TNM were obtained from cancer registry records used for an update of the Nordic cancer statistics database NORDCAN. Patients were followed for death or emigration through 2017. We calculated proportions of available TNM stage, stage distribution, and stage-specific relative survival under different approaches for each cancer site and country. RESULTS: Application of the assumptions yielded higher numbers of cases with available TNM stage for stages 0-I, II, and III. We observed only minor differences in stage-specific one-year relative survival when applying N0M0 for missing N and M, especially for high completeness of TNM registrations, whereas relative survival for remaining cases with missing TNM stage declined substantially. CONCLUSION: We found no major changes in stage-specific one-year relative survival applying N0M0 for NXMX. We conclude that complete TNM information is preferable to making assumptions, but it seems reasonable to consider assuming N0M0 for missing N and M in future studies based on the Nordic cancer registries. An automatic algorithm, though, is not recommended without considering potential area-specific reasons for frequent use of NX and MX. Clinicians should be urged to report complete TNM information to improve surveillance of the TNM stage.

Age-specific survival trends and life-years lost in women with breast cancer 1990-2016: the NORDCAN survival studies.

BACKGROUND: A recent overview of cancer survival trends 1990-2016 in the Nordic countries reported continued improvements in age-standardized breast cancer survival among women. The aim was to estimate age-specific survival trends over calendar time, including life-years lost, to evaluate if improvements have benefited patients across all ages in the Nordic countries. METHODS: Data on breast cancers diagnosed 1990-2016 in Denmark, Finland, Iceland, Norway, and Sweden were obtained from the NORDCAN database. Age-standardized and age-specific relative survival (RS) was estimated using flexible parametric models, as was reference-adjusted crude probabilities of death and life-years lost. RESULTS: Age-standardized period estimates of 5-year RS in women diagnosed with breast cancer ranged from 87% to 90% and 10-year RS from 74% to 85%. Ten-year RS increased with 15-18 percentage points from 1990 to 2016, except in Sweden (+9 percentage points) which had the highest survival in 1990. The largest improvements were observed in Denmark, where a previous survival disadvantage diminished. Most recent 5-year crude probabilities of cancer death ranged from 9% (Finland, Sweden) to 12% (Denmark, Iceland), and life-years lost from 3.3 years (Finland) to 4.6 years (Denmark). Although survival improvements were consistent across different ages, women aged ≥70 years had the lowest RS in all countries. Period estimates of 5-year RS were 94-95% in age 55 years and 84-89% in age 75 years, while 10-year RS were 88-91% in age 55 years and 69-84% in age 75 years. Women aged 40 years lost on average 11.0-13.8 years, while women lost 3.8-6.0 years if aged 55 and 1.9-3.5 years if aged 75 years. CONCLUSIONS: Survival for Nordic women with breast cancer improved from 1990 to 2016 in all age groups, albeit with larger country variation among older women where survival was also lower. Women over 70 years of age have not had the same survival improvement as women of younger age.

Differences in Incidence and Mortality Trends of Colorectal Cancer Worldwide Based on Sex, Age, and Anatomic Location.

BACKGROUND & AIMS: We studied incidence and mortality trends of colorectal cancer (CRC) in 39 countries according to age, sex, and anatomic location (colon vs rectum). METHODS: We retrieved incidence data from registries from 36 countries. The registries included the following: Cancer Incidence in 5 Continents volumes I to XI; the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute; and the Nordic Cancer Registries from Europe. We obtained mortality data from 39 countries of the World Health Organization database. We evaluated average annual percentage changes in CRC incidence and mortality in the past decade using joinpoint regression analysis. RESULTS: From 2007 to 2016, 2006 to 2015, or 2005 to 2014, depending on the availability of the data, the incidence of colon cancer increased in 10 of 36 countries analyzed (all in Asia or Europe); India had the greatest increase, followed by Poland. All 10 of these countries have medium to high Human Development Index (HDI) scores. Six countries had a decrease in colon cancer incidence; these countries had the highest HDI scores; the United States had the greatest decrease, followed by Israel. Seven countries (including all countries from Northern America) had a decrease in incidence among persons older than 50 years. Eight countries had an increase in colon cancer incidence among persons younger than 50 years, including the United Kingdom and India. Countries with a decreased or stable incidence among persons 50 years or older but a significant increase in persons younger than 50 years, included Germany, Australia, the United States, Sweden, Canada, and the United Kingdom. Only Italy had a decrease in CRC incidence among persons younger than 50 years. Among women, 12 of 36 countries (all from Asia and Europe) had an increase in colon cancer incidence and 7 countries had a decrease; India had the greatest increase followed by Slovenia. Five of 36 countries had an increase in incidence of rectal cancer and 8 countries had a decrease; Ecuador and Thailand had the greatest increases in incidence. The incidence of rectal cancer among persons younger than 50 years increased significantly in Finland, Australia, Canada, the United States, and The Netherlands. Four countries had an increase in the incidence of rectal cancer in women; Ecuador had the greatest increase followed by Thailand. The incidence of rectal cancer in women decreased in 8 countries. Among women younger than 50 years, rectal cancer incidence increased, despite a decrease in women older than 50 years, in Costa Rica, Slovenia, Japan, Slovakia, Canada, and the United States there was an increase in incidence, although their elder population had a stable or decreased incidence. Twenty-four countries reported a reduction in CRC mortality, including North America, Oceania, and most European countries. Nevertheless, some countries from Asia, Latin America, and Southern Europe had significant increases in CRC mortality. CONCLUSIONS: In an analysis of incidence and mortality databases from 39 countries, we found that the incidence of colon and rectal cancers has continued to increase in countries with medium to high HDI and in younger populations. Preventive strategies are needed for countries with increasing CRC and rectal cancer incidence and mortality.

Trends in cancer survival in the Nordic countries 1990-2016: the NORDCAN survival studies.

BACKGROUND: Differences in cancer survival between the Nordic countries have previously been reported. The aim of this study was to examine whether these differences in outcome remain, based on updated information from five national cancer registers. MATERIALS AND METHODS: The data used for the analysis was from the NORDCAN database focusing on nine common cancers diagnosed 1990-2016 in Denmark, Finland, Iceland, Norway and Sweden with maximum follow-up through 2017. Relative survival (RS) was estimated at 1 and 5 years using flexible parametric RS models, and percentage point differences between the earliest and latest years available were calculated. RESULTS: A consistent improvement in both 1- and 5-year RS was found for most studied sites across all countries. Previously observed differences between the countries have been attenuated. The improvements were particularly pronounced in Denmark that now has cancer survival similar to the other Nordic countries. CONCLUSION: The reasons for the observed improvements in cancer survival are likely multifactorial, including earlier diagnosis, improved treatment options, implementation of national cancer plans, uniform national cancer care guidelines and standardized patient pathways. The previous survival disadvantage in Denmark is no longer present for most sites. Continuous monitoring of cancer survival is of importance to assess the impact of changes in policies and the effectiveness of health care systems.

Time trends and occupational variation in the incidence of testicular cancer in the Nordic countries.

OBJECTIVE: To describe the trends and occupational variation in the incidence of testicular cancer in the Nordic countries utilising national cancer registries, NORDCAN (NORDCAN project/database presents the incidence, mortality, prevalence and survival from >50 cancers in the Nordic countries) and NOCCA (Nordic Occupational Cancer) databases. PATIENTS AND METHODS: We obtained the incidence data of testicular cancer for 5-year periods from 1960-1964 to 2000-2014 and for 5-year age-groups from the NORDCAN database. Morphological data on incident cases of seminoma and non-seminoma were obtained from national cancer registries. Age-standardised incidence rates (ASR) were calculated per 100 000 person-years (World Standard). Regression analysis was used to evaluate the annual change in the incidence of testicular cancer in each of the Nordic countries. The risk of testicular cancer in different professions was described based on NOCCA information and expressed as standardised incidence ratios (SIRs). RESULTS: During 2010-2014 the ASR for testicular cancer varied from 11.3 in Norway to 5.8 in Finland. Until 1998, the incidence was highest in Denmark. There has not been an increase in Denmark and Iceland since the 1990s, whilst the incidence is still strongly increasing in Norway, Sweden, and Finland. There were no remarkable changes in the ratio of seminoma and non-seminoma incidences during the past 50 years. There was no increase in the incidences in children and those of pension age. The highest significant excess risks of testicular seminoma were found in physicians (SIR 1.48, 95% confidence interval [CI] 1.07-1.99), artistic workers (SIR 1.47, 95% CI 1.06-1.99) and religious workers etc. (SIR 1.33, 95% CI 1.14-1.56). The lowest SIRs of testicular seminoma were seen amongst cooks and stewards (SIR 0.56, 95% CI 0.29-0.98), and forestry workers (SIR 0.64, 95% CI 0.47-0.86). The occupational category of administrators was the only one with a significantly elevated SIR for testicular non-seminoma (SIR 1.21, 95% CI 1.04-1.42). The only SIRs significantly <1.0 were seen amongst engine operators (SIR 0.60, 95% CI 0.41-0.84) and public safety workers (SIR 0.67, 95% CI 0.43-0.99). CONCLUSIONS: There have always been differences in the incidence of testicular cancer between the Nordic countries. There is also some divergence in the incidences in different age groups and in the trends of the incidence. The effect of occupation-related factors on incidence of testicular cancer is only moderate. Our study describes the differences, but provides no explanation for this variation.

Increasing incidence of thyroid cancer in the Nordic countries with main focus on Swedish data.

BACKGROUND: Radiofrequency radiation in the frequency range 30 kHz-300 GHz was evaluated to be Group 2B, i.e. 'possibly' carcinogenic to humans, by the International Agency for Research on Cancer (IARC) at WHO in May 2011. Among the evaluated devices were mobile and cordless phones, since they emit radiofrequency electromagnetic fields (RF-EMF). In addition to the brain, another organ, the thyroid gland, also receives high exposure. The incidence of thyroid cancer is increasing in many countries, especially the papillary type that is the most radiosensitive type. METHODS: We used the Swedish Cancer Register to study the incidence of thyroid cancer during 1970-2013 using joinpoint regression analysis. RESULTS: In women, the incidence increased statistically significantly during the whole study period; average annual percentage change (AAPC) +1.19 % (95 % confidence interval (CI) +0.56, +1.83 %). Two joinpoints were detected, 1979 and 2001, with a high increase of the incidence during the last period 2001-2013 with an annual percentage change (APC) of +5.34 % (95 % CI +3.93, +6.77 %). AAPC for all men during 1970-2013 was +0.77 % (95 % CI -0.03, +1.58 %). One joinpoint was detected in 2005 with a statistically significant increase in incidence during 2005-2013; APC +7.56 % (95 % CI +3.34, +11.96 %). Based on NORDCAN data, there was a statistically significant increase in the incidence of thyroid cancer in the Nordic countries during the same time period. In both women and men a joinpoint was detected in 2006. The incidence increased during 2006-2013 in women; APC +6.16 % (95 % CI +3.94, +8.42 %) and in men; APC +6.84 % (95 % CI +3.69, +10.08 %), thus showing similar results as the Swedish Cancer Register. Analyses based on data from the Cancer Register showed that the increasing trend in Sweden was mainly caused by thyroid cancer of the papillary type. CONCLUSIONS: We postulate that the whole increase cannot be attributed to better diagnostic procedures. Increasing exposure to ionizing radiation, e.g. medical computed tomography (CT) scans, and to RF-EMF (non-ionizing radiation) should be further studied. The design of our study does not permit conclusions regarding causality.

Survival trends for patients diagnosed with cutaneous malignant melanoma in the Nordic countries 1990-2016: The NORDCAN survival studies.

BACKGROUND: The survival in patients diagnosed with cutaneous malignant melanoma (CMM) has improved in the Nordic countries in the last decades. It is of interest to know if these improvements are observed in all ages and for both women and men. METHODS: Patients diagnosed with CMM in the Nordic countries in 1990-2016 were identified in the NORDCAN database. Flexible parametric relative survival models were fitted, except for Iceland where a non-parametric Pohar-Perme approach was used. A range of survival metrics were estimated by sex, both age-standardised and age-specific. RESULTS: The 5-year relative survival improved in all countries, in both women and men and across age. While the improvement was more pronounced in men, women still had a higher survival at the end of the study period. The survival was generally high, with age-standardised estimates of 5-year relative survival towards the end of the study period ranging from 85% in Icelandic men to 95% in Danish women. The age-standardised and reference-adjusted 5-year crude probability of death due to CMM ranged from 5% in Danish and Swedish women to 13% in Icelandic men. CONCLUSION: Although survival following CMM was relatively high in the Nordic countries in 1990, continued improvements in survival were observed throughout the study period in both women and men and across age.

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.

Incidence, mortality and relative survival of patients with cancer of the bladder and upper urothelial tract in the Nordic countries between 1990 and 2019.

PURPOSE: To understand the potential impact of new treatment options for urinary tract cancer, recent population trends in incidence, mortality and survival should be elucidated. This study estimated changes in the incidence, mortality and relative survival of urinary tract cancer in the Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) between 1990 and 2019. METHODS: Annual counts of incident cases and deaths due to urinary tract cancer (International Classification of Diseases, Tenth Revision, Clinical Modification codes C65-C68, D09.0-D09.1, D30.1-D30.9 and D41.1-D41.9) in Nordic countries were retrieved in 5-year age categories by sex during the study period. Country-specific time trends (annual rate ratios [RRs]) were estimated using Poisson regression, and RRs were compared between sexes. RESULTS: The incidence rate of bladder and upper urothelial tract cancer was >3-times lower in women than men in all countries across all age groups (incidence RR for women to men ranging from 0.219 [95% CI = 0.213-0.224] in Finland to 0.291 [95% CI = 0.286-0.296] in Denmark). Incidence rates were lowest in Finland and highest in Norway and Denmark. Age-adjusted mortality decreased in Finland, Denmark and Norway and in Swedish men, with the greatest decrease seen in Danish men (annual RR = 0.976; 95% CI = 0.975-0.978). In all countries and age groups, women had a lower relative survival rate than men. CONCLUSION: Between 1990 and 2019, the incidence of urinary tract cancer was stable in the Nordic countries, while mortality rates declined and relative survival increased. This could be due to earlier diagnosis and better treatment.

Survival trends in patients diagnosed with colon and rectal cancer in the nordic countries 1990-2016: The NORDCAN survival studies.

BACKGROUND: Survival of patients with colon and rectal cancer has improved in all Nordic countries during the past decades. The aim of this study was to further assess survival trends in patients with colon and rectal cancer in the Nordic countries by age at diagnosis and to present additional survival measures. METHODS: Data on colon and rectal cancer cases diagnosed in the Nordic countries between 1990 and 2016 were obtained from the NORDCAN database. Relative survival was estimated using flexible parametric models. Both age-standardized and age-specific measures for women and men were estimated from the models, as well as reference-adjusted crude probabilities of death and life-years lost. RESULTS: The five-year age-standardized relative survival of colon and rectal cancer patients continued to improve for women and men in all Nordic countries, from around 50% in 1990 to about 70% at the end of the study period. In general, survival was similar across age and sex. The largest improvement was seen for Danish men and women with rectal cancer, from 41% to 69% and from 43% to 71%, respectively. The age-standardized and reference-adjusted five-year crude probability of death in colon cancer ranged from 30% to 36% across countries, and for rectal cancer from 20% to 33%. The average number of age-standardized and reference-adjusted life-years lost ranged between six and nine years. CONCLUSION: There were substantial improvements in colon and rectal cancer survival in all Nordic countries 1990-2016. Of special note is that the previously observed survival disadvantage in Denmark is no longer present.

Risk of primary brain tumour after breast cancer.

INTRODUCTION: Cancer registry data in the USA indicated that women diagnosed with breast cancer before the age of 40 were at increased risk of a new primary tumour within the brain and women aged 50 years or above were at lower risk than expected. Our aim was to investigate if similar results could be found in Danish population-based data, considering an explanatory role of hormonal status. METHODS: Our study cohort included all women diagnosed with breast cancer below the age of 60 between 1978 and 2013 in Denmark. A total of 47,920 women were followed up in the Danish Cancer Registry for primary brain cancer. Standardized incidence ratios (observed/expected cases (O/E)) were used to estimate the risk of getting a primary brain tumour in the breast cancer cohort. RESULTS: Data indicated an increased tendency of brain cancer following breast cancer at ages below 60 years (O/E = 1.24). For premenopausal women (age <49 at the diagnosis of breast cancer) the O/E was 1.25. Stratifying by time of breast cancer diagnosis, we observed an increased risk of being diagnosed with a brain tumour among women aged 49 years or younger at breast cancer diagnosis between 2004 and 2013. CONCLUSION: The results indicate an increased tendency of developing a primary brain tumour in women with previous breast cancer history. Whereas the finding in premenopausal women is in line with the SEER data, the finding among postmenopausal is not. Primary brain tumours in breast cancer patients call for research in genetics and hormones to establish common risk factors.

Is the Increasing Incidence of Thyroid Cancer in the Nordic Countries Caused by Use of Mobile Phones?

The International Agency for Research on Cancer (IARC) at the World Health Organization (WHO) categorized in 2011 radiofrequency (RF) as a possible human carcinogen, Group 2B. During use of the handheld wireless phone, especially the smartphone, the thyroid gland is a target organ. During the 21st century, the incidence of thyroid cancer is increasing in many countries. We used the Swedish Cancer Register to study trends from 1970 to 2017. During that time period, the incidence increased statistically significantly in women with average annual percentage change (AAPC) +2.13%, 95% confidence interval (CI) +1.43, +2.83%. The increase was especially pronounced during 2010-2017 with annual percentage change (APC) +9.65%, 95% CI +6.68, +12.71%. In men, AAPC increased during 1970-2017 with +1.49%, 95% CI +0.71, +2.28%. Highest increase was found for the time period 2001-2017 with APC +5.26%, 95% CI +4.05, +6.49%. Similar results were found for all Nordic countries based on NORDCAN 1970-2016 with APC +5.83%, 95% CI +4.56, +7.12 in women from 2006 to 2016 and APC + 5.48%, 95% CI +3.92, +7.06% in men from 2005 to 2016. According to the Swedish Cancer Register, the increasing incidence was similar for tumors ≤4 cm as for tumors >4 cm, indicating that the increase cannot be explained by overdiagnosis. These results are in agreement with recent results on increased thyroid cancer risk associated with the use of mobile phones. We postulate that RF radiation is a causative factor for the increasing thyroid cancer incidence.