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Tor Åge Myklebust

Bio: Tor Åge Myklebust is an academic researcher from Norwegian Institute of Public Health. The author has contributed to research in topics: Medicine & Population. The author has an hindex of 16, co-authored 70 publications receiving 1066 citations.

Papers published on a yearly basis

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Journal ArticleDOI
TL;DR: Progress in cancer control over the study period was evident for stomach, colon, lung (in males), and ovarian cancer, and the impact of comorbidity are likely the main determinants of patient outcomes.
Abstract: Summary Background Population-based cancer survival estimates provide valuable insights into the effectiveness of cancer services and can reflect the prospects of cure. As part of the second phase of the International Cancer Benchmarking Partnership (ICBP), the Cancer Survival in High-Income Countries (SURVMARK-2) project aims to provide a comprehensive overview of cancer survival across seven high-income countries and a comparative assessment of corresponding incidence and mortality trends. Methods In this longitudinal, population-based study, we collected patient-level data on 3·9 million patients with cancer from population-based cancer registries in 21 jurisdictions in seven countries (Australia, Canada, Denmark, Ireland, New Zealand, Norway, and the UK) for seven sites of cancer (oesophagus, stomach, colon, rectum, pancreas, lung, and ovary) diagnosed between 1995 and 2014, and followed up until Dec 31, 2015. We calculated age-standardised net survival at 1 year and 5 years after diagnosis by site, age group, and period of diagnosis. We mapped changes in incidence and mortality to changes in survival to assess progress in cancer control. Findings In 19 eligible jurisdictions, 3 764 543 cases of cancer were eligible for inclusion in the study. In the 19 included jurisdictions, over 1995–2014, 1-year and 5-year net survival increased in each country across almost all cancer types, with, for example, 5-year rectal cancer survival increasing more than 13 percentage points in Denmark, Ireland, and the UK. For 2010–14, survival was generally higher in Australia, Canada, and Norway than in New Zealand, Denmark, Ireland, and the UK. Over the study period, larger survival improvements were observed for patients younger than 75 years at diagnosis than those aged 75 years and older, and notably for cancers with a poor prognosis (ie, oesophagus, stomach, pancreas, and lung). Progress in cancer control (ie, increased survival, decreased mortality and incidence) over the study period was evident for stomach, colon, lung (in males), and ovarian cancer. Interpretation The joint evaluation of trends in incidence, mortality, and survival indicated progress in four of the seven studied cancers. Cancer survival continues to increase across high-income countries; however, international disparities persist. While truly valid comparisons require differences in registration practice, classification, and coding to be minimal, stage of disease at diagnosis, timely access to effective treatment, and the extent of comorbidity are likely the main determinants of patient outcomes. Future studies are needed to assess the impact of these factors to further our understanding of international disparities in cancer survival. Funding Canadian Partnership Against Cancer; Cancer Council Victoria; Cancer Institute New South Wales; Cancer Research UK; Danish Cancer Society; National Cancer Registry Ireland; The Cancer Society of New Zealand; National Health Service England; Norwegian Cancer Society; Public Health Agency Northern Ireland, on behalf of the Northern Ireland Cancer Registry; The Scottish Government; Western Australia Department of Health; and Wales Cancer Network.

555 citations

Journal ArticleDOI
TL;DR: The aim of this study was to evaluate local recurrence after TaTME, and aims included postoperative mortality, anastomotic leak and stoma rates.
Abstract: BACKGROUND Transanal total mesorectal excision (TaTME) for rectal cancer has emerged as an alternative to the traditional abdominal approach. However, concerns have been raised about local recurrence. The aim of this study was to evaluate local recurrence after TaTME. Secondary aims included postoperative mortality, anastomotic leak and stoma rates. METHODS Data on all patients who underwent TaTME were recorded and compared with those from national cohorts in the Norwegian Colorectal Cancer Registry (NCCR) and the Norwegian Registry for Gastrointestinal Surgery (NoRGast). Kaplan-Meier estimates were used to compare local recurrence. RESULTS In Norway, 157 patients underwent TaTME for rectal cancer between October 2014 and October 2018. Three of seven hospitals abandoned TaTME after a total of five procedures. The local recurrence rate was 12 of 157 (7·6 per cent); eight local recurrences were multifocal or extensive. The estimated local recurrence rate at 2·4 years was 11·6 (95 per cent c.i. 6·6 to 19·9) per cent after TaTME compared with 2·4 (1·4 to 4·3) per cent in the NCCR (P < 0·001). The adjusted hazard ratio was 6·71 (95 per cent c.i. 2·94 to 15·32). Anastomotic leaks resulting in reoperation occurred in 8·4 per cent of patients in the TaTME cohort compared with 4·5 per cent in NoRGast (P = 0·047). Fifty-six patients (35·7 per cent) had a stoma at latest follow-up; 39 (24·8 per cent) were permanent. CONCLUSION Anastomotic leak rates after TaTME were higher than national rates; local recurrence rates and growth patterns were unfavourable.

165 citations

Journal ArticleDOI
TL;DR: Improvements in rectal cancer treatment have led to decreased recurrence rates of 5% and increased survival on a national level and here results from the Norwegian Colorectal Cancer Registry from 1993 to 2010 are presented.
Abstract: Background. The Norwegian Rectal Cancer Project was initated in 1993 with the aims of improving surgery, decreasing local recurrence rates, improving survival, and establishing a national rectal cancer registry. Here we present results from the Norwegian Colorectal Cancer Registry (NCCR) from 1993 to 2010.Material and methods. A total of 15 193 patients were diagnosed with rectal cancer in Norway 1993–2010, and were registered with clinical data regarding diagnosis, treatment, locoregional recurrences and distant metastases. Of these, 10 796 with non-metastatic disease underwent tumour resection. The results were stratified into five time periods, and the treatment outcomes were compared. Recurrence rates are presented for the 9785 patients who underwent curative major resection (R0/R1).Results. Among all 15 193 patients, relative five-year survival increased from 54.1% in 1993–1997 to 63.4% in 2007–2010 (p < 0.001). Among the 10 796 patients with stage I–III disease who underwent tumour resection, from 1...

71 citations

Journal ArticleDOI
TL;DR: Aspirin use after the diagnosis of CRC is independently associated with improved CSS and OS and may be more justified from a risk-benefit perspective.
Abstract: PurposeRegular use of aspirin (acetylsalicylic acid) is associated with reduced incidence and mortality of colorectal cancer (CRC). However, aspirin as primary prevention is debated because of the risk of hemorrhagic adverse effects. Aspirin as secondary prevention may be more justified from a risk-benefit perspective. We have examined the association between aspirin use after the diagnosis of CRC with CRC-specific survival (CSS) and overall survival (OS).Materials and MethodsAn observational, population-based, retrospective cohort study was conducted by linking patients diagnosed with CRC from 2004 through 2011 (Cancer Registry of Norway) with data on their aspirin use (The Norwegian Prescription Database). These registries cover more than 99% of the Norwegian population and include all patients in an unselected and consecutive manner. Exposure to aspirin was defined as receipt of aspirin prescriptions for more than 6 months after the diagnosis of CRC. Multivariable Cox-proportional hazard analyses were ...

59 citations

Journal ArticleDOI
TL;DR: Clomiphene citrate appears associated with increased risk of ovarian and endometrial cancer, and increased risks of breast and thyroid cancer were less consistent across type of drug exposure and parity.
Abstract: Background: Long-term safety of assisted reproductive techniques (ART) is of interest as their use is increasing. Cancer risk is known to be affected by parity. This study examined the risk of cancer after fertility treatment, stratified by women9s parity. Methods: Data were obtained from all women ( n = 1,353,724) born in Norway between 1960 and 1996. Drug exposure data (2004–2014) were obtained from the Norwegian Prescription Database (drugs used in ART and clomiphene citrate). The Medical Birth Registry of Norway provided parity status. HRs were calculated for all site cancer, breast, cervical, endometrial, ovarian, colorectal, central nervous system, thyroid cancer, and malignant melanoma. Results: In 12,354,392 person-years of follow-up, 20,128 women were diagnosed with cancer. All-site cancer risk was 1.14 [95% confidence interval (95% CI), 1.03–1.26] and 1.10 (95% CI, 0.98–1.23) after clomiphene citrate and ART exposure, respectively. For ovarian cancer, a stronger association was observed for both exposures in nulliparous (HR, 2.49; 95% CI, 1.30–4.78; and HR, 1.62; 95% CI, 0.78–3.35) versus parous women (HR, 1.37; 95% CI, 0.64–2.96; and HR, 0.87; 95% CI, 0.33–2.27). Elevated risk of endometrial cancers was observed for clomiphene citrate exposure in nulliparous women (HR, 4.49; 95% CI, 2.66–7.60 vs. HR, 1.52; 95% CI, 0.67–3.42). Risk was elevated for breast cancer in parous women exposed to clomiphene citrate (HR, 1.26; 95% CI, 1.03–1.54) for thyroid cancer and among nulliparous women after ART treatment (HR, 2.19; 95% CI, 1.08–4.44). Conclusions: Clomiphene citrate appears associated with increased risk of ovarian and endometrial cancer. Elevations in risks of breast and thyroid cancer were less consistent across type of drug exposure and parity. Impact: Continued monitoring of fertility treatments is warranted. Cancer Epidemiol Biomarkers Prev; 26(6); 953–62. ©2017 AACR .

51 citations


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TL;DR: A status report on the global burden of cancer worldwide using the GLOBOCAN 2018 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer, with a focus on geographic variability across 20 world regions.
Abstract: This article provides a status report on the global burden of cancer worldwide using the GLOBOCAN 2018 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer, with a focus on geographic variability across 20 world regions There will be an estimated 181 million new cancer cases (170 million excluding nonmelanoma skin cancer) and 96 million cancer deaths (95 million excluding nonmelanoma skin cancer) in 2018 In both sexes combined, lung cancer is the most commonly diagnosed cancer (116% of the total cases) and the leading cause of cancer death (184% of the total cancer deaths), closely followed by female breast cancer (116%), prostate cancer (71%), and colorectal cancer (61%) for incidence and colorectal cancer (92%), stomach cancer (82%), and liver cancer (82%) for mortality Lung cancer is the most frequent cancer and the leading cause of cancer death among males, followed by prostate and colorectal cancer (for incidence) and liver and stomach cancer (for mortality) Among females, breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death, followed by colorectal and lung cancer (for incidence), and vice versa (for mortality); cervical cancer ranks fourth for both incidence and mortality The most frequently diagnosed cancer and the leading cause of cancer death, however, substantially vary across countries and within each country depending on the degree of economic development and associated social and life style factors It is noteworthy that high-quality cancer registry data, the basis for planning and implementing evidence-based cancer control programs, are not available in most low- and middle-income countries The Global Initiative for Cancer Registry Development is an international partnership that supports better estimation, as well as the collection and use of local data, to prioritize and evaluate national cancer control efforts CA: A Cancer Journal for Clinicians 2018;0:1-31 © 2018 American Cancer Society

58,675 citations

Journal ArticleDOI
TL;DR: The GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer (IARC) as mentioned in this paper show that female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung cancer, colorectal (11 4.4%), liver (8.3%), stomach (7.7%) and female breast (6.9%), and cervical cancer (5.6%) cancers.
Abstract: This article provides an update on the global cancer burden using the GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer. Worldwide, an estimated 19.3 million new cancer cases (18.1 million excluding nonmelanoma skin cancer) and almost 10.0 million cancer deaths (9.9 million excluding nonmelanoma skin cancer) occurred in 2020. Female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung (11.4%), colorectal (10.0 %), prostate (7.3%), and stomach (5.6%) cancers. Lung cancer remained the leading cause of cancer death, with an estimated 1.8 million deaths (18%), followed by colorectal (9.4%), liver (8.3%), stomach (7.7%), and female breast (6.9%) cancers. Overall incidence was from 2-fold to 3-fold higher in transitioned versus transitioning countries for both sexes, whereas mortality varied <2-fold for men and little for women. Death rates for female breast and cervical cancers, however, were considerably higher in transitioning versus transitioned countries (15.0 vs 12.8 per 100,000 and 12.4 vs 5.2 per 100,000, respectively). The global cancer burden is expected to be 28.4 million cases in 2040, a 47% rise from 2020, with a larger increase in transitioning (64% to 95%) versus transitioned (32% to 56%) countries due to demographic changes, although this may be further exacerbated by increasing risk factors associated with globalization and a growing economy. Efforts to build a sustainable infrastructure for the dissemination of cancer prevention measures and provision of cancer care in transitioning countries is critical for global cancer control.

35,190 citations

Journal ArticleDOI
01 Apr 2017-Gut
TL;DR: Pattern and trends in CRC incidence and mortality correlate with present human development levels and their incremental changes might reflect the adoption of more western lifestyles, pointing towards widening disparities and an increasing burden in countries in transition.
Abstract: Objective The global burden of colorectal cancer (CRC) is expected to increase by 60% to more than 2.2 million new cases and 1.1 million deaths by 2030. In this study, we aim to describe the recent CRC incidence and mortality patterns and trends linking the findings to the prospects of reducing the burden through cancer prevention and care. Design Estimates of sex-specific CRC incidence and mortality rates in 2012 were extracted from the GLOBOCAN database. Temporal patterns were assessed for 37 countries using data from Cancer Incidence in Five Continents (CI5) volumes I–X and the WHO mortality database. Trends were assessed via the annual percentage change using joinpoint regression and discussed in relation to human development levels. Results CRC incidence and mortality rates vary up to 10-fold worldwide, with distinct gradients across human development levels, pointing towards widening disparities and an increasing burden in countries in transition. Generally, CRC incidence and mortality rates are still rising rapidly in many low-income and middle-income countries; stabilising or decreasing trends tend to be seen in highly developed countries where rates remain among the highest in the world. Conclusions Patterns and trends in CRC incidence and mortality correlate with present human development levels and their incremental changes might reflect the adoption of more western lifestyles. Targeted resource-dependent interventions, including primary prevention in low-income, supplemented with early detection in high-income settings, are needed to reduce the number of patients with CRC in future decades.

3,321 citations

Journal ArticleDOI
TL;DR: The present estimates of the cancer burden in Europe alongside a description of the profiles of common cancers at the national and regional level provide a basis for establishing priorities for cancer control actions across Europe.

1,650 citations

Journal ArticleDOI
TL;DR: There was a uniform decrease in gastric cancer incidence but an increasing incidence of colorectal cancer in formerly low-incidence regions over the studied time period, and slight increases in incidence of liver and pancreatic cancer in some high-income regions.

670 citations