Occupation and tongue cancer in Nordic countries.

PURPOSE: Almost 200,000 tongue cancers were diagnosed worldwide in 2020. The aim of this study was to describe occupational risk variation in this malignancy. METHODS: The data are based on the Nordic Occupational Cancer (NOCCA) study containing 14.9 million people from the Nordic countries with 9020 tongue cancers diagnosed during 1961-2005. The standardized incidence ratio (SIR) of tongue cancer in each occupational category was calculated using national incidence rates as the reference. RESULTS: Among men, the incidence was statistically significantly elevated in waiters (SIR 4.36, 95% confidence interval (CI) 3.13--5.92), beverage workers (SIR 3.42, 95% CI 2.02-5.40), cooks and stewards (SIR 2.55, 95% CI 1.82-3.48), seamen (SIR 1.66, 95% CI 1.36-2.00), journalists (SIR 1.85, 95% CI 1.18-2.75), artistic workers (SIR 2.05, 95% CI 1.54-2.66), hairdressers (SIR 2.17, 95% CI 1.39-3.22), and economically inactive persons (SIR 1.57, 95% CI 1.42-1.73). Among women, the SIR was statistically significantly elevated only in waitresses (SIR 1.39, 95% CI 1.05-1.81). Statistically significant SIRs ≤ 0.63 were observed in male farmers, gardeners, forestry workers and teachers, and in female launderers. CONCLUSIONS: These findings may be related to consumption of alcohol and tobacco, but the effect of carcinogenic exposure from work cannot be excluded.

Variant in the synaptonemal complex protein SYCE2 associates with pregnancy loss through effect on recombination.

Two-thirds of all human conceptions are lost, in most cases before clinical detection. The lack of detailed understanding of the causes of pregnancy losses constrains focused counseling for future pregnancies. We have previously shown that a missense variant in synaptonemal complex central element protein 2 (SYCE2), in a key residue for the assembly of the synaptonemal complex backbone, associates with recombination traits. Here we show that it also increases risk of pregnancy loss in a genome-wide association analysis on 114,761 women with reported pregnancy loss. We further show that the variant associates with more random placement of crossovers and lower recombination rate in longer chromosomes but higher in the shorter ones. These results support the hypothesis that some pregnancy losses are due to failures in recombination. They further demonstrate that variants with a substantial effect on the quality of recombination can be maintained in the population.

[Breastfeeding in Iceland: Changes in prevalence and duration over a century].

INTRODUCTION: Worldwide, the health-promoting effects of breastfeeding on children and their mothers are indisputable. The frequency and duration of breastfeeding varies greatly internationally but studies on prevalence and influencing factors of breastfeeding in Iceland are scanty and the published ones deal with small groups. The aim of this research is to describe the epidemiology of breastfeeding duration and its influencing factors in Iceland among a large cohort in a whole population over almost one century. MATERIAL AND METHODS: This is a historical cohort study, using data from The Cancer Detection Clinic Cohort of The Icelandic Cancer Society, collected retrospectively by questionnaires during the years 1964-2008. The data consisted of mothers´ reported information on breastfeeding of their 81,889 children, 36,537 first-borns and 45,352 younger siblings. The frequency and duration of breastfeeding was calculated and the effects of the following exposure variables were assessed: Maternal age, BMI (N=4950, data collected 1979-2008) and smoking (N=32.087, data collected 1995-2008), the child's year of birth and its order in the sibling group. RESULTS: The children were born in the period of 1917-2008. In the late 1970s, the average duration of breastfeeding began to increase, in all age groups of mothers, increasing rapidly from 3 months to 7-8 months. At about the same time, the breastfeeding duration increased depending on the birth order of the children, younger children were breastfed for longer than their older siblings. Women with normal weight (BMI 18.5 to 24.9) breastfed their babies the longest, while obese women breastfed the shortest. Women with any history of smoking reported shorter duration of breastfeeding than women who had never smoked. CONCLUSION: The increase in the average duration of breastfeeding in Iceland a few decades ago is in accordance with the information in the World Health Organization's database from European countries 1975-2000, where the Nordic countries and most Northern European countries promoted breastfeeding at a similar time. High BMI and maternal smoking are important variables when studying breastfeeding and this study indicates their negative association with the duration of breastfeeding.

Estrogen receptor-positive breast cancer and adverse outcome in BRCA2 mutation carriers and young non-carrier patients.

Estrogen receptor-positive (ER+) breast cancer generally confers a more favorable prognosis than ER-negative cancer, however, a different picture is emerging for BRCA2 mutation carriers and young patients. We used nationwide data from population-based registries to study prognostic effects in those two groups. Of all 2817 eligible women diagnosed with breast cancer in Iceland during 1980-2004, 85% had been tested for the Icelandic 999del5 BRCA2 (c.771_775delTCAAA) founder pathogenic variant. We compared breast cancer-specific survival, effects of ER status, other clinical parameters, and treatment, between three mutually exclusive groups: BRCA2-carriers, non-carriers diagnosed 40 years or younger, and older non-carriers. Prevalence of the BRCA2 mutation among tested patients <=40 years of age was 21.0%, but it was 5.4% among women diagnosed >40 years of age. For ER+ cancer, breast cancer-specific 15-year survival was 49.7%, 55.2%, and 74.7%, among BRCA2-carriers, young and older non-carriers, respectively, whereas for ER-negative cancer, survival was similar (64.0-69.3%) for all three groups. Neither BRCA2 carriers nor young non-carriers did tumor grade 3 predict worse survival than did tumor grade 1. The adverse outcome for the young cases cannot be explained by BRCA2 mutations, as carriers were excluded from the group. Those two clinically important patient groups need special attention with respect to treatment choices, in particular, if diagnosed with ER+ tumors. It is thus advisable to have knowledge of BRCA2 status when treatment decisions are made. Finally, it is important to understand the biological basis for the specific nature of ER+ tumors in young women and BRCA2 carriers.

Genetics and epidemiology of mutational barcode-defined clonal hematopoiesis.

Clonal hematopoiesis (CH) arises when a substantial proportion of mature blood cells is derived from a single hematopoietic stem cell lineage. Using whole-genome sequencing of 45,510 Icelandic and 130,709 UK Biobank participants combined with a mutational barcode method, we identified 16,306 people with CH. Prevalence approaches 50% in elderly participants. Smoking demonstrates a dosage-dependent impact on risk of CH. CH associates with several smoking-related diseases. Contrary to published claims, we find no evidence that CH is associated with cardiovascular disease. We provide evidence that CH is driven by genes that are commonly mutated in myeloid neoplasia and implicate several new driver genes. The presence and nature of a driver mutation alters the risk profile for hematological disorders. Nevertheless, most CH cases have no known driver mutations. A CH genome-wide association study identified 25 loci, including 19 not implicated previously in CH. Splicing, protein and expression quantitative trait loci were identified for CD164 and TCL1A.

Deficit of homozygosity among 1.52 million individuals and genetic causes of recessive lethality.

Genotypes causing pregnancy loss and perinatal mortality are depleted among living individuals and are therefore difficult to find. To explore genetic causes of recessive lethality, we searched for sequence variants with deficit of homozygosity among 1.52 million individuals from six European populations. In this study, we identified 25 genes harboring protein-altering sequence variants with a strong deficit of homozygosity (10% or less of predicted homozygotes). Sequence variants in 12 of the genes cause Mendelian disease under a recessive mode of inheritance, two under a dominant mode, but variants in the remaining 11 have not been reported to cause disease. Sequence variants with a strong deficit of homozygosity are over-represented among genes essential for growth of human cell lines and genes orthologous to mouse genes known to affect viability. The function of these genes gives insight into the genetics of intrauterine lethality. We also identified 1077 genes with homozygous predicted loss-of-function genotypes not previously described, bringing the total set of genes completely knocked out in humans to 4785.

[Cohort study on the experiences of cancer diagnosis and treatment in Iceland in the year 2015-2019].

INTRODUCTION: In the coming years, an increase in the number of cancer cases can be expected in Iceland. It is important to gain more insight into the experiences of the diagnostic- and treatment phase among those diagnosed with cancer to improve quality of life and life expectancy. METHODS: The study included 4575 individuals diagnosed with cancer between 2015 and 2019 in Iceland, 18 years or older at the time. Participants answered an on-line questionnaire once between 2020 and 2021. RESULTS: A total of 1672 (37%) individuals responded to the questionnaire. The mean age at diagnosis was 59 years (±12). The majority of participants were informed on their cancer diagnosis during a doctor's appointment (67%), but a quarter (25%) received the information by telephone. A total of 77% of participants were satisfied with the diagnostic process, thereof relatively fewer women than men (73% vs. 83%) (p<0,001). Fewer of those who received the cancer diagnosis by telephone were pleased with the diagnostic process (62%) compared with those receiving information during a doctor's appointment (85%) (p<0,001). More women (58%) than men (33%) expressed the need for support regarding mental well-being from healthcare professionals during the diagnostic process (p<0.001). In 2015, 36% of participants started treatment more than month after diagnosis, compared with 51% in 2019. The need for various specific resources during treatment, e.g. physiotherapy, psychological services or nutritional counseling were regularly assessed among 20-30% of participants. CONCLUSION: A quarter of respondents diagnosed with cancer received information about the diagnosis over the phone instead of an interview. There is a suggestion that the time from diagnosis to the start of cancer treatment is increasing. It is necessary to assess whether it is possible to support individuals with cancer better during the diagnostic- and treatment phase based on their individual needs.

The impact of the COVID-19 pandemic on cancer diagnosis based on pathology notifications: A comparison across the Nordic countries during 2020.

The severity of the COVID-19 pandemic and subsequent mitigation strategies have varied across the Nordic countries. In a joint Nordic population-based effort, we compared patterns of new cancer cases and notifications between the Nordic countries during 2020. We used pathology notifications to cancer registries in Denmark, the Faroe Islands, Finland, Iceland, Norway and Sweden to determine monthly numbers of pathology notifications of malignant and in situ tumours from January to December 2020 compared to 2019 (2017-2019 for Iceland and the Faroe Islands). We compared new cancer cases per month based on unique individuals with pathology notifications. In April and May 2020, the numbers of new malignant cases declined in all Nordic countries, except the Faroe Islands, compared to previous year(s). The largest reduction was observed in Sweden (May: -31.2%, 95% CI -33.9, -28.3), followed by significant declines in Finland, Denmark and Norway, and a nonsignificant decline in Iceland. In Denmark, Norway, Sweden and Finland the reporting rates during the second half of 2020 rose to almost the same level as in 2019. However, in Sweden and Finland, the increase did not compensate for the spring decline (annual reduction -6.2% and -3.6%, respectively). Overall, similar patterns were observed for in situ tumours. The COVID-19 pandemic led to a decline in rates of new cancer cases in Sweden, Finland, Denmark and Norway, with the most pronounced reduction in Sweden. Possible explanations include the severity of the pandemic, temporary halting of screening activities and changes in healthcare seeking behaviour.

Laryngeal and Pharyngeal Squamous Cell Carcinoma After Antireflux Surgery in the 5 Nordic Countries.

OBJECTIVE: The aim of this study was to clarify whether antireflux surgery prevents laryngeal and pharyngeal squamous cell carcinoma. SUMMARY BACKGROUND DATA: Gastroesophageal reflux disease (GERD) seems to increase the risk of laryngeal and pharyngeal squamous cell carcinoma. METHODS: All-Nordic (Denmark, Finland, Iceland, Norway, and Sweden) population-based cohort study of adults with documented GERD in 1980 to 2014. First, cancer risk after antireflux surgery was compared to the expected risk in the corresponding background population by calculating standardized incidence ratios (SIRs) with 95% confidence intervals (CIs). Second, cancer risk among antireflux surgery patients was compared to nonoperated GERD patients using multivariable Cox regression, providing hazard ratios (HR) with 95% CIs, adjusted for sex, age, calendar period, and diagnoses related to tobacco smoking, obesity, and alcohol overconsumption. RESULTS: Among 814,230 GERD patients, 47,016 (5.8%) underwent antireflux surgery. The overall SIRs and HRs of the combined outcome laryngeal or pharyngeal squamous cell carcinoma (n=39) were decreased after antireflux surgery [SIR=0.62 (95% CI 0.44-0.85) and HR=0.55 (95% CI 0.38-0.80)]. The point estimates were further decreased >10 years after antireflux surgery [SIR=0.48 (95% CI 0.26-0.80) and HR=0.47 (95% CI 0.26-0.85)]. The risk estimates of laryngeal squamous cell carcinoma were particularly decreased >10 years after antireflux surgery [SIR=0.28 (95% CI 0.08-0.72) and HR=0.23 (95% CI 0.08-0.69)], whereas no such decrease over time after surgery was found for pharyngeal squamous cell carcinoma. Analyses of patients with severe GERD (reflux esophagitis or Barrett esophagus) showed similar results. CONCLUSION: Antireflux surgery may decrease the risk of laryngeal squamous cell carcinoma and possibly also of pharyngeal squamous cell carcinoma.

Statins are associated with increased risk of squamous cell carcinoma of the skin: a whole-population study from Iceland.

Statins have been associated with an increased risk of keratinocyte carcinoma but data are limited and conflicting. Statins are hypothesized to contribute to KC through immunomodulation. A whole-population case-control study of the Icelandic population was conducted using the Icelandic Cancer Registry and Icelandic Prescription Medicine Register. These are high-quality registers which include all cancer diagnoses, as well as every prescription in the country. Cases included all first-time histologically confirmed diagnoses of (BCC), in situ squamous cell carcinoma (SCCis) and invasive SCC between 2003 and 2017. Each case was paired with 10 age- and sex-matched controls. Multivariate conditional logistic regression analysis was performed. Four thousand seven hundred patients with BCC, 1167 patients with SCCis and 1013 patients with invasive SCC were identified and paired with 47,292, 11,961 and 10,367 controls, respectively. Overall statin use was associated with an increased risk of invasive SCC and SCCis but not BCC (adjusted OR [95% CI]: 1.29 [1.11-1.50]; 1.43 [1.24-1.64]; 1.03 [0.95-1.12], respectively). Subgroup analysis demonstrated that statins were significantly associated with invasive SCC and SCCis in patients over 60, but not in those under 60. Atorvastatin was only associated with an increased risk of SCCis; whereas, simvastatin was associated with an increased risk of both invasive SCC and SCCis. This whole-population study of Iceland demonstrates that statin exposure is associated with increased risk of SCC, but not BCC, in a low UV environment. The reasons are unclear, but our results may suggest that individuals receiving atorvastatin and simvastatin have differing levels of baseline keratinocyte cancer risk or that properties of a statin other than 'statin intensity' affect association with SCC.

Risk Factors for Suicide After Bariatric Surgery in a Population-based Nationwide Study in Five Nordic Countries.

OBJECTIVE: To identify risk factors for suicide after bariatric surgery. SUMMARY BACKGROUND DATA: Bariatric surgery reduces obesity-related mortality. However, it is for unclear reasons is associated with an increased risk of suicide. METHODS: This population-based cohort study included patients having undergone bariatric surgery in 1982 to 2012 in any of the 5 Nordic countries, with follow-up through 2012. Eleven potential risk factors of suicide (sex, age, comorbidity, surgery type, surgical approach, calendar year of surgery, history of depression or anxiety, psychosis, schizophrenia, mania, or bipolar disorder, personality disorder, substance use, and number of previously documented psychiatric diagnoses) were analyzed using Cox regression. RESULTS: Of 49,977 bariatric surgery patients, 98 (0.2%) committed suicide during follow-up. Women had a decreased risk of suicide compared to men (hazard ratio [HR] = 0.48, 95% confidence interval [CI] 0.33-0.77), although age and comorbidity did not influence this risk. Compared to gastric bypass, other types of bariatric surgery had lower risk of suicide (HR = 0.44, 95%CI 0.27-0.99). There was no difference in suicide risk between laparoscopic and open surgical approach. A history of depression or anxiety (HR = 6.87, 95%CI 3.97-11.90); mania, bipolar disorder, psychosis, or schizophrenia (HR = 2.70, 95%CI 1.14-6.37); and substance use (HR = 2.28, 95%CI 1.08-4.80), increased the risk of suicide. More of the above psychiatric diagnoses increased the risk of suicide (HR = 22.59, 95%CI 12.96-39.38 for ≥2 compared to 0 diagnoses). CONCLUSIONS: Although the risk of suicide is low, psychiatric disorders, male sex, and gastric bypass procedure seem to increase the risk of suicide after bariatric surgery, indicating a role for tailored preoperative psychiatric evaluation and postoperative surveillance.

Growth Rate in Childhood and Adolescence and the Risk of Breast and Prostate Cancer: A Population-Based Study.

Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from ages 8 to 13 years (childhood) and from age 13 to attainment of adult height (adolescence), as measured at study entry, and the risk of breast or prostate cancer. Participants were 2,037 Icelanders born during 1915-1935, who took part in the Reykjavik Study, established in 1967. Height measurements were obtained from school records and at study entry. We used multivariable Cox regression models to calculate hazard ratios with 95% confidence intervals of breast and prostate cancer by rates of growth in tertiles. During a mean follow-up of 66 years (women) and 64 years (men), 117 women were diagnosed with breast cancer and 118 men with prostate cancer (45 with advanced disease). Women in the highest growth-rate tertile in adolescence had a higher risk of breast cancer (hazard ratio = 2.4, 95% confidence interval: 1.3, 4.3) compared with women in the lowest tertile. A suggestive inverse association was observed for highest adolescent growth rate in men and advanced prostate cancer: hazard ratio = 0.4, 95% confidence interval: 0.2, 1.0. Rapid growth, particularly in adolescence may affect cancer risk later in life.

Dietary patterns in adolescence and risk of colorectal cancer: a population-based study.

PURPOSE: To study whether dietary patterns in adolescence are associated with risk of colorectal cancer (CRC). METHODS: Food frequency data were obtained from the AGES-Reykjavik study, conducted between 2002 and 2006, which included 5,078 (58% women) participants with mean age of 77 (± 5.8) years. Principal component analysis was used to identify dietary patterns. Participants were followed through linkage to the Icelandic Cancer Registry. Multivariable Cox models were used to calculate hazard ratios (HR) of CRC and 95% confidence interval (CI) by dietary patterns. RESULTS: During the follow-up period (mean 8.2 years), 136 participants (75 women and 61 men) were diagnosed with CRC. The main dietary pattern in adolescence was characterized by high intake of traditional food items consumed in the earlier half of the twentieth century, namely, salted or smoked meat and fish, milk, offal, rye bread, and oatmeal. Compared to the lowest tertile, the middle tertile of this pattern was associated with increased risk of CRC (HR 1.63, 95% CI 1.04-2.57), while the highest tertile was not statistically associated with CRC (HR 1.48, 95% CI 0.93-2.37), except among women (HR 2.06, 95% CI 1.11-3.84). CONCLUSION: These data suggest that strong adherence to a traditional Icelandic diet in adolescence might increase the risk of CRC, particularly among women. More research is need on the association between food items and dietary patterns of relevance to CRC at different points in the life cycle.

[Screening for cancer of the colon and rectum A review on incidence, mortality, cost and benefit].

In this article the incidence and mortality for cancer of the colon and rectum in Iceland is discussed. The two most common screening methods, faecal immunochemical test (FIT) and colonoscopy are compared and an estimate of cost and benefits for the Icelandic society will be made. The incidence of cancer of the colon and rectum has been increasing in Iceland in last decades but mortality has decreased and survival improved. However, more individuals die from cancer of the colon and rectum than from both breast- and cervical cancer added together. It is likely that screening for cancer of the colon and rectum, could prevent at least 6 of the 28 deaths related to those cancers, occurring yearly in Iceland in screening age, given a screening ages of 50-74 years. The extra cost for the Icelandic community due to the implementation of screening for cancer of the colon and rectum will be acceptable due to the lower cost of simpler treatments, lower cancer incidence and reduced mortality.

Somatic Disease in Survivors of Childhood Malignant Bone Tumors in the Nordic Countries.

Survivors of malignant bone tumors in childhood are at risk of long-term adverse health effects. We comprehensively reviewed cases of somatic diseases that required a hospital contact in survivors of osteosarcoma and Ewing sarcoma. In a population-based cohort study, 620 five-year survivors of osteosarcoma (n = 440) or Ewing sarcoma (n = 180), diagnosed before the age of 20 years in Denmark, Finland, Iceland, and Sweden during 1943-2008, were followed in the national hospital registers. Overall rates of hospital contacts for any somatic disease and for 12 main diagnostic groups and 120 specific disease categories were compared with those in a matched comparison cohort (n = 3049) randomly selected from the national population registers. The rate of hospital contact for any somatic disease was 80% higher in survivors of malignant bone tumors than in comparisons and remained elevated up to 30 years after diagnosis. The rate of hospital contacts was higher after Ewing sarcoma (rate ratio (RR) 2.24; 95% confidence interval (CI) 1.76-2.85) than after osteosarcoma (RR 1.67; 95% CI 1.41-1.98). Elevated rates were observed for 11 main diagnostic groups, including infections, second malignant neoplasms, and diseases of the skin, bones, and circulatory, digestive, endocrine, and urinary systems. Survivors of malignant bone tumors in childhood are at increased risk of somatic diseases many years after diagnosis. This comprehensive study contributes new insight into the risk of late effects in survivors of osteosarcoma and Ewing sarcoma, which is an essential basis for optimal patient counseling and follow-up care.

Temporal changes in the probability of live birth among female survivors of childhood cancer: A population-based Adult Life After Childhood Cancer in Scandinavia (ALiCCS) study in five nordic countries.

BACKGROUND: During the past 4 decades, there has been a growing focus on preserving the fertility of patients with childhood cancer; however, no large studies have been conducted of live births across treatment decades during this period. Therefore, the authors estimated the potential birth deficit in female childhood cancer survivors and the probability of live births. METHODS: In total, 8886 women were identified in the 5 Nordic cancer registries in whom a childhood cancer had been diagnosed during 1954 through 2006. A population comparison cohort of 62,903 women was randomly selected from the central population registries matched by age and country. All women were followed for live births recorded in medical birth registries. The cumulative probability and the risk ratio (RR) with 95% confidence intervals (CIs) of a live birth were calculated by maternal age across treatment decades. RESULTS: The probability of a live birth increased with treatment decade, and, at age 30 years, the rate for survivors most recently diagnosed was close to the rate among the general population (1954-1969: RR, 0.65 [95% CI, 0.54-0.78]; 1970s: RR, 0.67 [95% CI, 0.60-0.74]; 1980s: RR, 0.69 [95% CI, 0.64-0.74]; 1990s: RR, 0.91 [95% CI, 0.87-0.95]; 2000s: RR, 0.94 [95% CI, 0.91-0.97]). CONCLUSIONS: Female childhood cancer survivors had a lower probability of a live birth than women in the general population, although, in survivors diagnosed after 1989, the probability was close to that of the general population. Because the pattern of live births differs by cancer type, continuous efforts must be made to preserve fertility, counsel survivors, and refer them rapidly to fertility treatment if necessary. LAY SUMMARY: The purpose of this study was to compare the probability of giving birth to a liveborn child in female survivors of childhood cancer with that of women in the general population. Survivors of childhood cancer had a lower probability of live births than women in the general population, although survivors diagnosed after 1989 had a probability close to that of the general population. Continuing focus on how to preserve the potential for fertility among female patients with childhood cancer during treatment is important to increase their chances of having a child.

Skeletal adverse events in childhood cancer survivors: An Adult Life after Childhood Cancer in Scandinavia cohort study.

The dynamic growth of the skeleton during childhood and adolescence renders it vulnerable to adverse effects of cancer treatment. The lifetime risk and patterns of skeletal morbidity have not been described in a population-based cohort of childhood cancer survivors. A cohort of 26 334 1-year cancer survivors diagnosed before 20 years of age was identified from the national cancer registries of Denmark, Finland, Iceland and Sweden as well as a cohort of 127 531 age- and sex-matched comparison subjects randomly selected from the national population registries in each country. The two cohorts were linked with data from the national hospital registries and the observed numbers of first-time hospital admissions for adverse skeletal outcomes among childhood cancer survivors were compared to the expected numbers derived from the comparison cohort. In total, 1987 childhood cancer survivors had at least one hospital admission with a skeletal adverse event as discharge diagnosis, yielding a rate ratio (RR) of 1.35 (95% confidence interval, 1.29-1.42). Among the survivors, we observed an increased risk for osteonecrosis with a RR of 25.9 (15.0-44.5), osteoporosis, RR 4.53 (3.28-6.27), fractures, RR 1.27 (1.20-1.34), osteochondropathies, RR 1.57 (1.28-1.92) and osteoarthrosis, RR 1.48 (1.28-1.72). The hospitalization risk for any skeletal adverse event was higher among survivors up to the age of 60 years, but the lifetime pattern was different for each type of skeletal adverse event. Understanding the different lifetime patterns and identification of high-risk groups is crucial for developing strategies to optimize skeletal health in childhood cancer survivors.

Cancer incidence among musicians: 45 years of follow-up in four Nordic countries.

BACKGROUND: There are studies suggesting that participation in musical activities may protect from cancer. On the other hand, some musicians have a lifestyle that might increase the risk of cancer. The objective of this study was to assess the cancer pattern of musicians in four Nordic countries. MATERIAL AND METHODS: This study combines census and cancer registry data from 1961 to 2005 for 13 million people from Finland, Iceland, Norway, and Sweden. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for entire national populations used as reference rates. RESULTS: There were 11,401 male and 3105 female musicians with 2039 cancer cases. The SIR for all sites combined was 1.02 (95% confidence interval 0.97-1.07) in men and 1.04 (0.94-1.15) in women. In male musicians, there were statistically significant excesses in oropharyngeal cancer (4.36, 2.73-6.60), esophageal cancer (2.08, 1.51-2.81), liver cancer (1.81, 1.26-2.52), and skin melanoma (1.40, 1.10-1.75). The risk was decreased in lip cancer (0.13, 0.02-0.48), stomach cancer (0.66, 0.50-0.82), and lung cancer (0.77, 0.65-0.90). In female musicians, there were no statistically significant SIRs in any of the cancer types studied, but the risk of breast cancer was significantly elevated in the age category of 70+ (1.52, 1.04-2.15). The overall SIR was stable over the 45 year period of observation, but strong decreases were observed in the SIRs of esophageal cancer, liver cancer, laryngeal cancer, and skin melanoma. CONCLUSION: Musicians have characteristics of indoor workers such as low incidence of lip cancer and high incidence of skin melanoma. The low incidence of lung cancer suggests that the prevalence of smoking among musicians is lower than in the general population while the elevated risk of alcohol-related cancer types suggest that drinking is likely more common among musicians. The cancer risk for all sites combined is still similar to that of the general population in the four countries studied.