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Dive into the research topics where Christoffer Johansen is active.

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Featured researches published by Christoffer Johansen.


Lancet Oncology | 2011

Prevalence of depression, anxiety, and adjustment disorder in oncological, haematological, and palliative-care settings: a meta-analysis of 94 interview-based studies

Alex J. Mitchell; Melissa Chan; Henna Bhatti; Marie Halton; Luigi Grassi; Christoffer Johansen; Nick Meader

BACKGROUND Substantial uncertainty exists about prevalence of mood disorders in patients with cancer, including those in oncological, haematological, and palliative-care settings. We aimed to quantitatively summarise the prevalence of depression, anxiety, and adjustments disorders in these settings. METHODS We searched Medline, PsycINFO, Embase, and Web of Knowledge for studies that examined well-defined depression, anxiety, and adjustment disorder in adults with cancer in oncological, haematological, and palliative-care settings. We restricted studies to those using psychiatric interviews. Studies were reviewed in accordance with PRISMA guidelines and a proportion meta-analysis was done. FINDINGS We identified 24 studies with 4007 individuals across seven countries in palliative-care settings. Meta-analytical pooled prevalence of depression defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) criteria was 16·5% (95% CI 13·1-20·3), 14·3% (11·1-17·9) for DSM-defined major depression, and 9·6% (3·6-18·1) for DSM-defined minor depression. Prevalence of adjustment disorder alone was 15·4% (10·1-21·6) and of anxiety disorders 9·8% (6·8-13·2). Prevalence of all types of depression combined was of 24·6% (17·5-32·4), depression or adjustment disorder 24·7% (20·8-28·8), and all types of mood disorder 29·0% (10·1-52·9). We identified 70 studies with 10,071 individuals across 14 countries in oncological and haematological settings. Prevalence of depression by DSM or ICD criteria was 16·3% (13·4-19·5); for DSM-defined major depression it was 14·9% (12·2-17·7) and for DSM-defined minor depression 19·2% (9·1-31·9). Prevalence of adjustment disorder was 19·4% (14·5-24·8), anxiety 10·3% (5·1-17·0), and dysthymia 2·7% (1·7-4·0). Combination diagnoses were common; all types of depression occurred in 20·7% (12·9-29·8) of patients, depression or adjustment disorder in 31·6% (25·0-38·7), and any mood disorder in 38·2% (28·4-48·6). There were few consistent correlates of depression: there was no effect of age, sex, or clinical setting and inadequate data to examine cancer type and illness duration. INTERPRETATION Interview-defined depression and anxiety is less common in patients with cancer than previously thought, although some combination of mood disorders occurs in 30-40% of patients in hospital settings without a significant difference between palliative-care and non-palliative-care settings. Clinicians should remain vigilant for mood complications, not just depression. FUNDING None.


British Journal of Cancer | 2005

Mobile phone use and risk of acoustic neuroma: results of the Interphone case–control study in five North European countries

Minouk J. Schoemaker; Anthony J. Swerdlow; Anders Ahlbom; Anssi Auvinen; Kg Blaasaas; Elisabeth Cardis; H. Collatz Christensen; Maria Feychting; Sarah J. Hepworth; Christoffer Johansen; Lars Klæboe; Stefan Lönn; Patricia A. McKinney; Kenneth Muir; Jani Raitanen; Tina Salminen; Jens Thomsen; Tore Tynes

There is public concern that use of mobile phones could increase the risk of brain tumours. If such an effect exists, acoustic neuroma would be of particular concern because of the proximity of the acoustic nerve to the handset. We conducted, to a shared protocol, six population-based case–control studies in four Nordic countries and the UK to assess the risk of acoustic neuroma in relation to mobile phone use. Data were collected by personal interview from 678 cases of acoustic neuroma and 3553 controls. The risk of acoustic neuroma in relation to regular mobile phone use in the pooled data set was not raised (odds ratio (OR)=0.9, 95% confidence interval (CI): 0.7–1.1). There was no association of risk with duration of use, lifetime cumulative hours of use or number of calls, for phone use overall or for analogue or digital phones separately. Risk of a tumour on the same side of the head as reported phone use was raised for use for 10 years or longer (OR=1.8, 95% CI: 1.1–3.1). The study suggests that there is no substantial risk of acoustic neuroma in the first decade after starting mobile phone use. However, an increase in risk after longer term use or after a longer lag period could not be ruled out.


Neurology | 2005

Cellular telephones and risk for brain tumors A population-based, incident case-control study

H. Collatz Christensen; Joachim Schüz; Michael Kosteljanetz; H. Skovgaard Poulsen; J. D. Boice; J. K. McLaughlin; Christoffer Johansen

Objective: To evaluate a possible association of glioma or meningioma with use of cellular telephones, using a nationwide population-based case-control study of incident cases of meningioma and glioma. Methods: The authors ascertained all incident cases of glioma and meningioma diagnosed in Denmark between September 1, 2000, and August 31, 2002. They enrolled 252 persons with glioma and 175 persons with meningioma aged 20 to 69. The authors also enrolled 822 randomly sampled, population-based controls matched for age and sex. Information was obtained from personal interviews, medical records containing diagnoses, and the results of radiologic examinations. For a small number of cases and controls, the authors obtained the numbers of incoming and outgoing calls. They evaluated the memory of the respondents with the Mini-Mental State Examination and obtained data on socioeconomic factors from Statistics Denmark. Results: There were no material socioeconomic differences between cases and controls or participants and non-participants. Use of cellular telephone was associated with a low risk for high-grade glioma (OR, 0.58; 95% CI, 0.37 to 0.90). The risk estimates were closer to unity for low-grade glioma (1.08; 0.58 to 2.00) and meningioma (1.00; 0.54 to 1.28). Conclusion: The results do not support an association between use of cellular telephones and risk for glioma or meningioma.


Occupational and Environmental Medicine | 2006

Validation of short term recall of mobile phone use for the Interphone study

Martine Vrijheid; Elisabeth Cardis; Bruce K. Armstrong; Anssi Auvinen; Gabriele Berg; Kg Blaasaas; Julianne Brown; Matthew Carroll; Angela Chetrit; Helle Collatz Christensen; Isabelle Deltour; Maria Feychting; Graham G. Giles; Sarah J. Hepworth; Martine Hours; Ivano Iavarone; Christoffer Johansen; Lars Klæboe; Päivi Kurttio; Susanna Lagorio; Stefan Lönn; Patricia A. McKinney; Lucile Montestrucq; Roger Parslow; Lesley Richardson; Siegal Sadetzki; Tiina Salminen; Joachim Schüz; Tore Tynes; Alistair Woodward

Aim: To validate short term recall of mobile phone use within Interphone, an international collaborative case control study of tumours of the brain, acoustic nerve, and salivary glands related to mobile telephone use. Methods: Mobile phone use of 672 volunteers in 11 countries was recorded by operators or through the use of software modified phones, and compared to use recalled six months later using the Interphone study questionnaire. Agreement between recalled and actual phone use was analysed using both categorical and continuous measures of number and duration of phone calls. Results: Correlations between recalled and actual phone use were moderate to high (ranging from 0.5 to 0.8 across countries) and of the same order for number and duration of calls. The kappa statistic demonstrated fair to moderate agreement for both number and duration of calls (weighted kappa ranging from 0.20 to 0.60 across countries). On average, subjects underestimated the number of calls per month (geometric mean ratio of recalled to actual = 0.92, 95% CI 0.85 to 0.99), whereas duration of calls was overestimated (geometric mean ratio = 1.42, 95% CI 1.29 to 1.56). The ratio of recalled to actual use increased with level of use, showing underestimation in light users and overestimation in heavy users. There was substantial heterogeneity in this ratio between countries. Inter-individual variation was also large, and increased with level of use. Conclusions: Volunteer subjects recalled their recent phone use with moderate systematic error and substantial random error. This large random error can be expected to reduce the power of the Interphone study to detect an increase in risk of brain, acoustic nerve, and parotid gland tumours with increasing mobile phone use, if one exists.


International Journal of Cancer | 2004

Incidence trends of adult primary intracerebral tumors in four Nordic countries

Stefan Lönn; Lars Klæboe; Per Hall; Tiit Mathiesen; Anssi Auvinen; Helle Collatz Christensen; Christoffer Johansen; Tiina Salminen; Tore Tynes; Maria Feychting

Brain tumors are some of the most lethal adult cancers and there is a concern that the incidence is increasing. It has been suggested that the reported increased incidence can be explained by improvements in diagnostic procedures, although this has not been totally resolved. The aim of our study was to describe the incidence trends of adult primary intracerebral tumors in four Nordic countries during a period with introduction of new diagnostic procedures and increasing prevalence of mobile phone users. Information about benign and malignant primary intracerebral tumor cases 20–79 years of age was obtained from the national cancer registries in Denmark, Finland, Norway and Sweden for the years 1969–98 and estimates of person‐years at risk were calculated from the information obtained from national population registries. Annual age standardized incidence rates per 100,000 person‐years were calculated and time trends analyses were carried out using Poisson regression. The overall incidence of all intracerebral tumors ranged from 8.4–11.8 for men and 5.8–9.3 for women, corresponding to an average annual increase of 0.6% for men (95% confidence interval [CI] = 0.4, 0.7) and 0.9% for women (95% CI = 0.7, 1.0). The increase in the incidence was confined to the late 1970s and early 1980s and coinciding with introduction of improved diagnostic methods. This increase was largely confined to the oldest age group. After 1983 and during the period with increasing prevalence of mobile phone users, the incidence has remained relatively stable for both men and women.


British Journal of Cancer | 1999

Gallstones, cholecystectomy and risk of cancers of the liver, biliary tract and pancreas

Wong Ho Chow; Christoffer Johansen; Gloria Gridley; Lene Mellemkjær; Jens Olsen; Joseph F. Fraumeni

SummaryTo examine the association between gallstones and cholecystectomy, we conducted a nationwide population-based cohort study in Denmark. Patients with a discharge diagnosis of gallstones from 1977 to 1989 were identified from the Danish National Registry of Patients and followed up for cancer occurrence until death or the end of 1993 by record linkage to the Danish Cancer Registry. Included in the cohort were 60 176 patients, with 471 450 person–years of follow-up. Cancer risks were estimated by standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) stratified by years of follow-up and by cholecystectomy status. Among patients without cholecystectomy, the risks at 5 or more years of follow-up were significantly elevated for cancers of liver (SIR = 2.0, CI = 1.2–3.1) and gallbladder (SIR = 2.7, CI = 1.5–4.4) and near unity for cancers of extrahepatic bile duct (SIR = 1.1), ampulla of Vater (SIR = 1.0) and pancreas (SIR = 1.1). The excess risk of liver cancer was seen only among patients with a history of hepatic disease. Among cholecystectomy patients, the risks at 5 or more years of follow-up declined for cancers of liver (SIR = 1.1) and extrahepatic bile duct (SIR = 0.7), but were elevated for cancers of ampulla of Vater (SIR = 2.0, CI = 1.0–3.7) and pancreas (SIR = 1.3, CI = 1.1–1.6). These findings confirm that gallstone disease increases the risk of gallbladder cancer, whereas cholecystectomy appears to increase the risk of cancers of ampulla of Vater and pancreas. Further research is needed to clarify the carcinogenic risks associated with gallstones and cholecystectomy and to define the mechanisms involved.


Cancer Epidemiology | 2011

Acoustic neuroma risk in relation to mobile telephone use: Results of the INTERPHONE international case-control study

Elisabeth Cardis; Isabelle Deltour; Martine Vrijheid; A. S Evrard; M Moissonnier; Bruce K. Armstrong; Julianne Brown; Graham G. Giles; Jack Siemiatycki; Louise Nadon; Marie-Elise Parent; Daniel Krewski; M. M McBride; Christoffer Johansen; Helle Collatz Christensen; Anssi Auvinen; Päivi Kurttio; Anna Lahkola; Tina Salminen; Martine Hours; Marlène Bernard; L. Montestruq; Joachim Schüz; Maria Blettner; Gabriele Berg-Beckhoff; Brigitte Schlehofer; Siegal Sadetzki; Angela Chetrit; Avital Jarus-Hakak; Susanna Lagorio

BACKGROUND The rapid increase in mobile telephone use has generated concern about possible health risks of radiofrequency electromagnetic fields from these devices. METHODS A case-control study of 1105 patients with newly diagnosed acoustic neuroma (vestibular schwannoma) and 2145 controls was conducted in 13 countries using a common protocol. Past mobile phone use was assessed by personal interview. In the primary analysis, exposure time was censored at one year before the reference date (date of diagnosis for cases and date of diagnosis of the matched case for controls); analyses censoring exposure at five years before the reference date were also done to allow for a possible longer latent period. RESULTS The odds ratio (OR) of acoustic neuroma with ever having been a regular mobile phone user was 0.85 (95% confidence interval 0.69-1.04). The OR for ≥10 years after first regular mobile phone use was 0.76 (0.52-1.11). There was no trend of increasing ORs with increasing cumulative call time or cumulative number of calls, with the lowest OR (0.48 (0.30-0.78)) observed in the 9th decile of cumulative call time. In the 10th decile (≥1640 h) of cumulative call time, the OR was 1.32 (0.88-1.97); there were, however, implausible values of reported use in those with ≥1640 h of accumulated mobile phone use. With censoring at 5 years before the reference date the OR for ≥10 years after first regular mobile phone use was 0.83 (0.58-1.19) and for ≥1640 h of cumulative call time it was 2.79 (1.51-5.16), but again with no trend in the lower nine deciles and with the lowest OR in the 9th decile. In general, ORs were not greater in subjects who reported usual phone use on the same side of the head as their tumour than in those who reported it on the opposite side, but it was greater in those in the 10th decile of cumulative hours of use. CONCLUSIONS There was no increase in risk of acoustic neuroma with ever regular use of a mobile phone or for users who began regular use 10 years or more before the reference date. Elevated odds ratios observed at the highest level of cumulative call time could be due to chance, reporting bias or a causal effect. As acoustic neuroma is usually a slowly growing tumour, the interval between introduction of mobile phones and occurrence of the tumour might have been too short to observe an effect, if there is one.


Acta Oncologica | 2011

Cancer rehabilitation: A Nordic and European perspective.

Maria Hellbom; Corinna Bergelt; Mia Bergenmar; Brigitte Gijsen; Jon Håvard Loge; Matti Rautalathi; Agnes Smaradottir; Christoffer Johansen

Abstract Background. The increasing incidence of cancer combined with prolonged survival times seen throughout the western world increases the need for rehabilitation. Diagnosis and treatment for cancer may have substantial effects on the patients’ physical, psychological, social and existential well-being. The aim of this paper is to describe the current situation in cancer rehabilitation in the Nordic countries, the Netherlands and Germany. Material and methods. Description of the current situation in cancer rehabilitation in the Nordic countries and literature review. Results. Rehabilitation as defined by multiple organizations covers a multidimensional view on chronic disease and its effect on the patients life. The rehabilitation systems in Denmark, Finland, Sweden, Germany and the Netherlands differ depending on the differing social security and health-care systems, but rehabilitation provided is largely based on a similar, multidimensional and multidisciplinary understanding of cancer rehabilitation. Research on rehabilitation efforts in European countries indicates that there is substantial evidence with regard to single interventions which can be part of cancer rehabilitation. Discussion. In order to assure patients and families continuing quality of life, rehabilitation should be an integral and continuous part of all cancer care.


Journal of Affective Disorders | 2012

Meta-analysis of screening and case finding tools for depression in cancer: Evidence based recommendations for clinical practice on behalf of the Depression in Cancer Care consensus group

Alex J. Mitchell; Nick Meader; Evan Davies; Kerrie Clover; Gregory Carter; Matthew Loscalzo; Wolfgang Linden; Luigi Grassi; Christoffer Johansen; Linda E. Carlson; James Zabora

BACKGROUND To examine the validity of screening and case-finding tools used in the identification of depression as defined by an ICD10/DSM-IV criterion standard. METHODS We identified 63 studies involving 19 tools (in 33 publications) designed to help clinicians identify depression in cancer settings. We used a standardized rating system. We excluded 11 tools without at least two independent studies, leaving 8 tools for comparison. RESULTS Across all cancer stages there were 56 diagnostic validity studies (n=10,009). For case-finding, one stem question, two stem questions and the BDI-II all had level 2 evidence (2a, 2b and 2c respectively) and given their better acceptability we gave the stem questions a grade B recommendation. For screening, two stem questions had level 1b evidence (with high acceptability) and the BDI-II had level 2c evidence. For every 100 people screened in advanced cancer, the two questions would accurately detect 18 cases, while missing only 1 and correctly reassure 74 with 7 falsely identified. For every 100 people screened in non-palliative settings the BDI-II would accurately detect 17 cases, missing 2 and correctly re-assure 70, with 11 falsely identified as cases. The main cautions are the reliance on DSM-IV definitions of major depression, the large number of small studies and the paucity of data for many tools in specific settings. CONCLUSIONS Although no single tool could be offered unqualified support, several tools are likely to improve upon unassisted clinical recognition. In clinical practice, all tools should form part of an integrated approach involving further follow-up, clinical assessment and evidence based therapy.


Cancer Epidemiology, Biomarkers & Prevention | 2007

GLIOGENE—an International Consortium to Understand Familial Glioma

Beatrice Malmer; Phyllis Adatto; Georgina Armstrong; Jill S. Barnholtz-Sloan; Jonine L. Bernstein; Elizabeth B. Claus; Faith G. Davis; Richard S. Houlston; Dora Il'yasova; Robert B. Jenkins; Christoffer Johansen; Rose Lai; Ching Lau; Bridget J. McCarthy; Hanne Nielsen; Sara H. Olson; Siegal Sadetzki; Sanjay Shete; Fredrik Wiklund; Margaret Wrensch; Ping Yang; Melissa L. Bondy

Evidence for familial aggregation of glioma has been documented in both case-control and cohort studies and occurs apart from the well-described rare inherited genetic syndromes involving glioma: neurofibromatosis type 1 and 2, tuberous sclerosis, Turcots syndrome, and Li-Fraumeni syndrome. Nonsyndromic glioma families have been studied but no genes have been identified in the two published linkage studies of familial glioma probably due to the small number of families. Because glioma is a rare but devastating cancer, and a family history of glioma has been observed in ∼5% of the cases, we initiated an international consortium to identify glioma families not affected by syndromes to better understand the inherited factors related to this disease. The international consortium GLIOGENE is an acronym for “glioma gene” and includes 15 research groups in North America, Europe, and Israel to study familial glioma. The overarching goal is to characterize genes in glioma families using a genome-wide single-nucleotide polymorphism approach and conducting linkage analysis to identify new genomic regions or loci that could harbor genes important for gliomagenesis. Here, we review the rationale for studying familial glioma and our proposed strategy for the GLIOGENE study. (Cancer Epidemiol Biomarkers Prev 2007;16(9):1730–4)

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Jonine L. Bernstein

Memorial Sloan Kettering Cancer Center

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