Relative risk of second malignant neoplasms highest among young adult cancer patients - a population-based registry study in Finland.

BACKGROUND AND PURPOSE: The objective of this study was to explore the incidence of second malignant neoplasms (SMNs) among adult cancer patients in Finland diagnosed with their first primary cancer (FPC) in 1992-2021. MATERIAL AND METHODS: The study used data from the population-based Finnish Cancer Registry (FCR). Risk estimates were calculated using the standardised incidence ratio (SIR), the ratio of observed second cancers compared to the expected numbers assuming the same cancer incidence as the corresponding sex-age-calendar year -split of the general population. RESULTS: A total of 573,379 FPCs were diagnosed during 1992-2021. During the follow-up, 60,464 SMNs were diagnosed. Male cancer patients had neither a decreased nor an increased risk (SIR 1.00 [95% CI, 0.99-1.01]) and female patients had an 8% increased risk (SIR 1.08 [95% CI, 1.06-1.09]) of developing any SMN compared to a FPC in the general population. The highest SIR of any SMN was observed in patients aged 20-39 -years at FPC diagnosis, and the SIR decreased by increasing age at diagnosis. Patients with lymphoid and haematopoietic tissue neoplasms, cancers of the mouth and pharynx, endocrine glands, respiratory and intrathoracic organs, skin, and urinary organs had the highest SIRs, while patients with cancers of the male genital organs and the female breast had the lowest SIRs. INTERPRETATION: Elevated SIRs were observed in cancer patients diagnosed at an early age and for FPCs known to be in large part attributable to lifestyle factors, which highlights the importance of monitoring and encouraging lifestyle changes.

Pairwise association of key lifestyle factors and risk of solid cancers - A prospective pooled multi-cohort register study.

Smoking, alcohol consumption, obesity, and physical inactivity are key lifestyle risk factors for cancer. Previously these have been mostly examined singly or combined as an index, assuming independent and equivalent effects to cancer risk. The aim of our study was to systematically examine the joint pairwise and interactive effects of these lifestyle factors on the risk of a first solid primary cancer in a multi-cohort prospective setting. We used pooled data from seven Finnish health survey studies during 1972-2015, with 197,551 participants diagnosed with 16,373 solid malignant primary tumors during follow-up. Incidence of any cancer was analyzed separately without and with lung cancers using Poisson regression with main and interaction effects of key lifestyle factors. When excluding lung cancer, the highest risk of any cancer in men was observed for smokers with a BMI of ≥25 kg/m2 (HR 1.36, 95 % CI 1.25-1.48) and in women for smokers consuming alcohol (HR 1.22, 1.14-1.30). No statistically significant interactions between any studied risk factor pairs were observed. When including lung cancer, the highest HRs among men were observed for smokers who consume alcohol (HR 1.72, 1.57-1.89) and among women for smokers who were physically inactive (HR 1.38, 1.27-1.49). Smoking combined with other lifestyle factors at any exposure level resulted in highest pairwise risks, both in men and women. These results highlight the importance of smoking prevention, but also the importance of preventing obesity and reducing alcohol consumption.

Every tenth malignant solid tumor attributed to overweight and alcohol consumption: A population-based cohort study.

BACKGROUND: Recent studies have shown that some four in ten cancers are attributable to a few key risk factors. The aim of this study was to estimate cohort-based population attributable fractions (PAFs) in Finland for potentially modifiable cancer risk factors. METHODS: Data from eight health studies including 253,953 subjects with 29,802 incident malignant solid tumors were analysed using Bayesian multivariate regression model with multiplicative risk factor effects. We estimated the effects of smoking, excess body weight, alcohol consumption, physical activity, parity and education on cancer incidence and related PAFs by cancer site, accounting for competing mortality. RESULTS: PAF for all cancer sites and exposures combined was 34% (95% credible interval 29%-39%) in men and 24% (19%-28%) in women. In men, 23% (21%-27%) and in women 8% (6%-9%) of all cancers were attributed to smoking. PAF related to excess body weight was 4% (2%-6%) in men and 5% (2%-7%) in women, to alcohol 7% (3%-10%) in men and 4% (0%-7%) in women, and to excess body weight and alcohol combined 10% (6%-15%) in men and 9% (4%-13%) in women. CONCLUSION: Smoking was the most important factor contributing to cancer burden in Finnish men and women over the last 40 years. The contribution of excess body weight and alcohol consumption together outweighed the role of smoking in women. As the prevalence of overweight is expected to increase, more efficient public health measures supporting adherence to healthy weight are essential to reduce cancer burden.

Partial substitution of red meat or processed meat with plant-based foods and the risk of colorectal cancer.

OBJECTIVES: Shifting from animal-based to plant-based diets could reduce colorectal cancer (CRC) incidence. Currently, the impacts of these dietary shifts on CRC risk are ill-defined. Therefore, we examined partial substitutions of red or processed meat with whole grains, vegetables, fruits or a combination of these in relation to CRC risk in Finnish adults. METHODS: We pooled five Finnish cohorts, resulting in 43 788 participants aged ≥ 25 years (79% men). Diet was assessed by validated food frequency questionnaires at study enrolment. We modelled partial substitutions of red (100 g/week) or processed meat (50 g/week) with corresponding amounts of plant-based foods. Cohort-specific hazard ratios (HR) for CRC were calculated using Cox proportional hazards models and pooled together using random-effects models. Adjustments included age, sex, energy intake and other relevant confounders. RESULTS: During the median follow-up of 28.8 years, 1124 CRCs were diagnosed. We observed small risk reductions when red meat was substituted with vegetables (HR 0.97, 95% CI 0.95 - 0.99), fruits (0.97, 0.94 - 0.99), or whole grains, vegetables and fruits combined (0.97, 0.95 - 0.99). For processed meat, these substitutions yielded 1% risk reductions. Substituting red or processed meat with whole grains was associated with a decreased CRC risk only in participants with < median whole grain intake (0.92, 0.86 - 0.98; 0.96, 0.93 - 0.99, respectively; pinteraction=0.001). CONCLUSIONS: Even small, easily implemented substitutions of red or processed meat with whole grains, vegetables or fruits could lower CRC risk in a population with high meat consumption. These findings broaden our insight into dietary modifications that could foster CRC primary prevention.

Occupational variation in incidence of oropharyngeal cancer in the Nordic countries.

PURPOSE: Evaluate the occupational variation in incidence of oropharyngeal cancer (OPC). METHODS: We calculated standardized incidence ratios (SIRs) of OPC in occupational categories in the Nordic countries relative to the entire national populations. The data covered 6155 OPC cases. RESULTS: Among men high risk of OPC was observed, among else, in waiters (SIR 6.28, 95% CI 4.68-8.26), beverage workers (SIR 3.00, 95% CI 1.72-4.88), and artistic workers (SIR 2.97, 95% CI 2.31-3.76). Among women high risk of OPC was observed in waiters (SIR 2.02, 95% CI 1.41-2.81) and packers (SIR 1.73, 95% CI 1.07-2.64). The lowest SIRs were observed in female gardeners (SIR 0.27, 95% CI 0.12-0.51) and male farmers (SIR 0.30, 95% CI 0.25-0.35). CONCLUSION: The 20-fold variation in incidence of OPC between occupations needs further investigation in studies with detailed information on occupational and non-occupational risk factors.

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

INTRODUCTION: Professional visual artists constitute a heterogeneous vocational group, including, but not limited to painters, photographers, textile artists, and sculptors who may face exposure to workplace hazardous substances and lifestyle factors that may contribute to the development of selected cancers. The objective of this registry-based cohort study was to assess the cancer incidence among Nordic visual artists. MATERIALS AND METHODS: This study is based on data from the Nordic Occupational Cancer (NOCCA) project that combines census data of 15 million people from all Nordic countries and cancer registries from 1961 to 2005. For the present study we selected a cohort of visual artists from Finland, Iceland, Norway, and Sweden. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates. RESULTS: In male visual artists, there were statistically significant excesses in cancers of the tongue (SIR 2.91, 95% confidence interval 1.74-4.55), oral cavity (2.09, 1.26-3.27), pharynx (2.18, 1.45--3.15), testis (1.91, 1.11-3.05), renal pelvis (2.48, 1.42-4.03) and bladder (1.33, 1.14-1.55). The risk was significantly decreased for cancers of the lip (0.45, 0.18-0.93) and stomach (0.65, 0.50-0.84). In female visual artists, the only significantly increased risk was observed for breast cancer (1.29, 1.13-1.48) and the only significantly decreased risk for stomach cancer (0.43, 0.17-0.88). The incidence of lung cancer was close to the population average in both sexes. CONCLUSIONS: The non-elevated incidence of lung cancer suggests a similar prevalence of smoking between visual artists and the general population, while the elevated risk of cancers of mouth and pharynx among male visual artists is suggestive of more widespread alcohol drinking. The excess risk of urogenital cancers might be associated with exposure to solvents.

The exposure of visual artists to carcinogens remains unstudied and equivocal. The current study suggests that visual artists carry an overall cancer risk that is slightly above the risk among the general population of the four Nordic countries. We observed in men over two-fold excess risks of cancers of the tongue, oral cavity, pharynx, and renal pelvis, and also a significant risk of testis and bladder cancers.

No Excess Cancer Risk among Veterinarians in Denmark, Finland, Iceland, Norway, and Sweden after the 1980s.

The cancer profile of veterinarians has received little research attention, despite the profession potentially being exposed to a wide range of known and suspected carcinogens. In this large-scale cohort study, we assessed cancer incidence in veterinarians in Denmark, Finland, Iceland, Norway, and Sweden, across more than 40 years (1961-2005). The cohort comprised 4708 veterinarians and 119,503 person-years at follow-up. The overall cancer incidence in veterinarians was close to the incidence in the total population in all countries and in all age groups. In male veterinarians, the standardized incidence ratios (SIR) in 1961-1990 were elevated for colon cancer (1.86, 95% confidence interval (CI) 1.39-2.44), prostate cancer (1.35, 95% CI 1.07-1.67), and especially skin melanoma (3.62, 95% CI 2.78-2.84), while there was no longer any statistically significant excess in the more recent follow-up period. Decreased SIRs were observed for lip cancer (0.11, 95% CI 0.00-0.62), laryngeal cancer (0.38, 95% CI 0.12-0.89), lung cancer (0.59, 95% CI 0.47-0.74), and stomach cancer (0.58, 95% CI 0.38-0.86), without a marked change in SIR over time. Non-significant excesses among male veterinarians were also observed in Hodgkin lymphoma (1961-1990 only), and leukaemia. This multi-country study indicates that there was an elevated incidence of several cancer types among male veterinarians before the 1990s but not after that. Some of the findings might rather be attributed to lifestyle factors and not directly to work conditions, but the excess risk of cancers of kidney and bladder, for example, might be related to work exposures.

Occupational variation in the incidence of lip cancer in the Nordic countries.

INTRODUCTION: While certain occupations, such as agriculture and fishery, have been associated with an increased risk of lip cancer, the occupational risk profile of lip cancer and its change over time remain poorly known. This study aims to evaluate the incidence of lip cancer across different occupations in the Nordic countries. METHODS: The Nordic Occupational Cancer Study (NOCCA) covers 14.9 million people and includes 45 years of cancer incidence data, from 1961 to 2005, linked to occupational categories for all the five Nordic populations. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were used to quantify the risk of lip cancer across occupational categories relative to the entire national populations. RESULTS: There were a total of 14,477 male and 3008 female lip cancer patients identified during follow up. The highest SIRs were observed among male fishermen (SIR 2.26, 95% CI: 2.04-2.50), gardeners (SIR 1.60, 95% CI: 1.48-1.72), and farmers (SIR 1.60, 95% CI: 1.55-1.66). A significantly reduced risk of lip cancer (SIR < 0.50) was observed among male physicians, teachers, religious workers, artistic workers, journalists, administrators, printers, waiters, and hairdressers. Among women, no occupations were associated with an increased risk of lip cancer. CONCLUSIONS: The incidence of lip cancer varies widely between outdoor and indoor occupations. Occupations involving outdoor activity and exposure to sunlight show the most elevated SIRs.

Certain outdoor occupations, such as agriculture and fishery, have been associated with an increased risk of lip cancer. However, the occupational risk profile of lip cancer and its change over time remain poorly known. This study highlights the excess risk of lip cancer among men with outdoor occupations and further corroborates previous studies. Efforts to counsel outdoor workers on the risk and prevention of lip cancer are needed to reduce the societal burden of the disease.

Familial aggregation of early-onset cancers in early-onset breast cancer families.

The risk of early-onset (EO) breast cancer is known to be increased in relatives of EO breast cancer patients, but less is known about the familial risk of other EO cancers. We assessed familial risks of EO cancers (aged ≤40 years) other than breast cancer in 54 753 relatives of 5562 women with EO breast cancer (probands) by using a population-based cohort from Finland. Standardized incidence ratios (SIRs) and 95% confidence intervals (CI) were estimated by using gender-, age- and period-specific cancer incidences of the general population as reference. The risk of any cancer excluding breast cancer in first-degree relatives was comparable to population cancer risk (SIR 0.99, 95% CI: 0.84-1.16). Siblings' children of women with EO breast cancer were at an elevated risk of EO testicular and ovarian cancer (SIR = 1.74, 95% CI: 1.07-2.69 and 2.69, 95% CI: 1.08-5.53, respectively). The risk of EO pancreatic cancer was elevated in siblings of the probands (7.61, 95% CI: 1.57-22.23) and an increased risk of any other cancer than breast cancer was observed in children of the probands (1.27, 95% CI: 1.03-1.55). In conclusion, relatives of women with EO breast cancer are at higher familial risk of certain discordant EO cancers, with the risk extending beyond first-degree relatives.

Early-onset grade 2-3 diffuse gliomas and schwannomas increase the risk of central nervous system tumors among the patients' relatives.

Background: Central nervous system (CNS) tumors are a heterogeneous group of tumors that include several aggressive malignancies with a high mortality rate. This study aimed to evaluate the familial relative risk of CNS tumors in family members of early-onset index cases (probands) in and between diffuse glioma, non-diffuse glioma, meningioma, and other CNS tumors. Methods: We retrieved tumor data from the Finnish cancer registry and familial relationships data from the population information system. We ascertained 5408 probands diagnosed with primary CNS tumors (age ≤40 years) between 1970 and 2012 in Finland. We report the standardized incidence ratios as a measure of familial aggregation using Poisson regression. Results: The risk of early-onset diffuse glioma increased among siblings of probands with the same tumor [SIR 3.85, 95% confidence interval (CI): 1.66-7.59], with association mainly returning to grade 2-3 diffuse gliomas. Early-onset other CNS tumors were associated with an increased risk of other CNS tumors, early-onset meningioma, and late-onset diffuse glioma in 1st-degree relatives. The elevated risk of other CNS tumors was largely caused by schwannomas (SIR 59.44, 95% CI: 27.18-112.84 for 1st-degree relatives) and associated with neurofibromatosis. No tumor syndrome was associated with an increased risk of diffuse gliomas. Conclusions: The early onset of grade 2-3 diffuse gliomas is associated with an increased risk of similar tumor entities. Early-onset schwannomas dramatically increase CNS tumor risk with a broader tumor-type profile. In future studies, it would be important to identify the underlying shared hereditary factors that contribute to the development of familial diffuse gliomas.

Incidence of cancer among Nordic police officers.

Police work may expose officers to various circumstances that have potential for increasing their risk of cancer, including traffic-related air pollution, night shift work and radiation from radars. In this study, we examined the incidence of cancer among Nordic male and female police officers. We utilize data from the Nordic Occupational Cancer (NOCCA) project, which linked census data on occupations from Finland, Iceland, Norway and Sweden to national cancer registries for the period 1961 to 2005. We report standardized incidence ratios (SIR) and 95% confidence intervals (CI) of selected cancers for each country by sex, age and calendar period. The cohort included 38 523 male and 1998 female police officers. As compared with the general population, male police officers had a 7% (95% CI: 4-9%) excess cancer risk, with elevated SIRs for various cancer sites, including prostate (SIR 1.19, 1.14-1.25), breast (SIR 1.77, 1.05-2.80), colon (SIR 1.22, 1.12-1.32) and skin melanoma (SIR 1.44, 1.28-1.60). Conversely, male police officers had a lower risk of lung cancer than the general population (SIR 0.72, 0.66-0.77). In female police officers, the SIR for cancer overall was 1.15 (0.98-1.34), and there was a slight excess of cancers of the breast (SIR 1.25, 0.97-1.59) and colon (SIR 1.21, 0.55-2.30). In conclusion, cancer incidence among the police officers was slightly higher than in the general population. Notably, SIRs were elevated for cancer sites potentially related to night shift work, namely colon, breast and prostate cancer.

Occupational risk variation of nasopharyngeal cancer in the Nordic countries.

BACKGROUND: The aim of this study was to estimate occupational risk variation in the incidence of nasopharyngeal cancer (NPC) in a large population-based cohort of the Nordic Occupational Cancer (NOCCA) study. METHODS: This study is based on a cohort of almost 15 million persons from Denmark, Finland, Iceland, Norway and Sweden, with 2898 nasopharyngeal cancer cases diagnosed in 1961-2005. The data on occupations were gathered from population censuses and cancer data from the national cancer registries. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were estimated using the national NPC incidence rates as the reference. RESULTS: There were 1980 male and 918 female NPC patients. The highest SIRs of NPC were observed among male waiters (SIR 3.69, 95% CI 1.91-6.45) and cooks and stewards (SIR 2.24, 95% CI 1.16-3.91). Among women, launderers had the highest SIR of NPC (2.04, 95% CI 1.02-3.65). Significantly decreased SIRs were found among male farmers (SIR 0.79, 95% CI 0.68-0.92) and male textile workers (SIR 0.49, 95% CI 0.22-0.93). CONCLUSIONS: This study suggests that NPC may be associated with several work-related exposure agents such as smoking, kitchen air pollution and solvents. In future, occupational exposure-risk relations should be studied to understand more about causality and to assess effective prevention strategies.

Sex-specific familial aggregation of cancers in Finland.

Despite the fact that the effect of sex on the occurrence of cancers has been studied extensively, it remains unclear whether sex modifies familial aggregation of cancers. We explored sex-specific familial aggregation of cancers in a large population-based historical cohort study. We combined cancer and population registry data, inferring familial relationships from birth municipality-surname-sex (MNS) combinations. Our data consisted of 391,529 incident primary cancers in 377,210 individuals with 319,872 different MNS combinations. Cumulative sex-specific numbers of cancers were compared to expected cumulative incidence. Familial cancer risks were similar between the sexes in our population-wide analysis. Families with concordant cancer in both sexes exhibited similar sex-specific cancer risks. However, some families had exceptionally high sex-specific cumulative cancer incidence. We identified six families with exceptionally strong aggregation in males: three families with thyroid cancer (ratio between observed and expected incidence 184.6; 95% credible interval (95% CI) 33.1-1012.7, 173.4 (95% CI 65.4-374.3), and 161.4 (95% CI 29.6-785.7), one with stomach (ratio 14.4 (95% CI 6.9-37.2)), colon (ratio 15.5 (95% CI 5.7-56.3)) cancers and one with chronic lymphocytic leukaemia (ratio 33.5 (95% CI 17.2-207.6)). Our results imply that familial aggregation of cancers shows no sex-specific preference. However, the atypical sex-specific aggregation of stomach cancer, colon cancer, thyroid cancer and chronic lymphocytic leukaemia in certain families is difficult to fully explain with present knowledge of possible causes, and could yield useful knowledge if explored further.

Malignant lymphoma and occupational exposure to extremely low frequency magnetic fields and electrical shocks: a nested case-control study in a cohort of four Nordic countries.

BACKGROUND: Exposure to extremely low frequency magnetic fields (ELF-MFs) and electric shocks is a common occupational risk factor in many workplaces. Recent investigations have highlighted a possible association between such exposures and lymphoma risk. This study was carried out to further explore the association between occupational exposure to ELF-MFs and electric shocks and risk of lymphoma in a large Nordic census-based cohort. METHODS: We included cases of non-Hodgkin's lymphoma (NHL, n=68 978), chronic lymphocytic leukaemia (CLL, n=20 615) and multiple myeloma (MM, n=35 467) diagnosed between 1961 and 2005 in Finland, Iceland, Norway and Sweden. Cases were matched to five controls by year of birth, sex and country. Lifetime occupational ELF-MF and electric shock exposures were assigned to jobs reported in population censuses using job-exposure matrices. The risk of cancer was assessed based on cumulative exposure to ELF-MF and electric shocks. ORs with 95% CIs were estimated using logistic models adjusted for occupational co-exposures relevant to lymphomas. RESULTS: Less than 7% of the cases experienced high levels of ELF-MF. We observed no increased risks among workers exposed to high levels of ELF-MF for NHL (OR: 0.93; CI 0.90 to 0.97), CLL (OR: 0.98; CI 0.92 to 1.05) or MM (OR: 0.96; CI 0.90 to 1.01). CONCLUSION: Our results do not provide support for an association between occupational exposure to ELF-MFs and electric shocks and lymphoma risk.

Pairwise association of key lifestyle factors and risk of colorectal cancer: a prospective pooled multicohort study.

BACKGROUND: Several lifestyle factors are associated with an increased risk of colorectal cancer (CRC). Although lifestyle factors co-occur, in most previous studies these factors have been studied focusing upon a single risk factor or assuming independent effects between risk factors. AIM: To examine the pairwise effects and interactions of smoking, alcohol consumption, physical inactivity, and body mass index (BMI) with risk of subsequent colorectal cancer (CRC). METHODS AND RESULTS: We used METCA cohort data (pooled data from seven population-based Finnish health behavior survey studies during years 1972-2015) consisting of 171 063 women and men. Participants' smoking, alcohol consumption, physical inactivity and BMI measures were gathered, and participants were categorized into those exposed and those not exposed. The incidence of CRC was modeled by Poisson regression with main and interaction effects of key lifestyle factors. The cohort members were followed-up through register linkage to the Finnish Cancer Registry for first primary CRC case until the end of 2015. Follow-up time was 1715, 690 person years. The highest pairwise CRC risk was among male smokers who had overweight (BMI ≥ 25 kg/m2 ) (HR 1.75, 95% CI 1.36-2.26) and women who had overweight and consumed alcohol (HR 1.45, 95% CI 1.14-1.85). Overall, among men the association of lifestyle factors and CRC risk was stronger than among women. In men, both having overweight and being a smoker combined with any other adverse lifestyle factor increased CRC risk. Among women, elevated CRC risks were observed for those who were physically inactive and who consumed alcohol or had overweight. No statistically significant interactions were detected between pairs of lifestyle factors. CONCLUSIONS: This study strengthens the evidence of overweight, smoking, and alcohol consumption as CRC risk factors. Substantial protective benefits in CRC risk can be achieved by preventing smoking, maintaining BMI to <25 kg/m2 and not consuming alcohol.

Socioeconomic status and risk of lung cancer by histological subtype in the Nordic countries.

BACKGROUND: While the excess in lung cancer risk among lower socioeconomic status individuals has been widely described, the magnitude of this association across lung cancer subtypes, as well as histotype-related long-term incidence trends, are inconclusively reported. AIMS: We explored the variation in the incidence of the three main lung cancer histotypes (i.e. squamous cell carcinoma, small cell carcinoma and adenocarcinoma) by socioeconomic status (SES, i.e. upper and lower white collar, upper and lower blue collar, and farming/forestry/fishing) in the adult population of four Nordic countries (i.e. Sweden, Norway, Finland and Denmark). MATERIALS & METHODS: We have used data from the Nordic Occupational Cancer Study (NOCCA), computing age-standardized incidence rates per 100,000 person-years truncated at ages 50-69 years, by sex, histotype, country and SES, for the period 1971-2005. We estimated relative risks and the corresponding 95% confidence intervals through Poisson regression models, including terms for SES, age, sex and country, as indicated. RESULTS: A clear socioeconomic gradient, with a progressive increase in lung cancer risk as SES level decreases, was observed in all subtypes and in both sexes. Favourable lung cancer incidence trends were seen among men for squamous cell and small cell carcinomas, although for adenocarcinomas rates were increasing everywhere except for Finland. Among women, upward temporal trends were seen in all SES groups and for all subtypes, although rates increased to a greater extent for low, compared to high, SES, especially in Denmark and Norway. Farmers showed comparatively lower risks compared to other SES categories. DISCUSSION: This prospective cohort study shows that substantial socioeconomic inequalities in the incidence of the most important lung cancer histotypes exist in the Nordic Countries, and that these inequalities are on the rise, especially among women. CONCLUSION: Smoking habits are likely to largely explain the observed social gradient for lung cancer histotypes in both sexes.

Parity associates with chromosomal damage in uterine leiomyomas.

Mechanical forces in a constrained cellular environment were recently established as a facilitator of chromosomal damage. Whether this could contribute to tumorigenesis is not known. Uterine leiomyomas are common neoplasms that display relatively few chromosomal aberrations. We hypothesized that if mechanical forces contribute to chromosomal damage, signs of this could be seen in uterine leiomyomas from parous women. We examined the karyotypes of 1946 tumors, and found a striking overrepresentation of chromosomal damage associated with parity. We then subjected myometrial cells to physiological forces similar to those encountered during pregnancy, and found this to cause DNA breaks and a DNA repair response. While mechanical forces acting in constrained cellular environments may thus contribute to neoplastic degeneration, and genesis of uterine leiomyoma, further studies are needed to prove possible causality of the observed association. No evidence for progression to malignancy was found.

Association between overall diet quality and postmenopausal breast cancer risk in five Finnish cohort studies.

There is limited evidence for any dietary factor, except alcohol, in breast cancer (BC) risk. Therefore, studies on a whole diet, using diet quality indices, can broaden our insight. We examined associations of the Nordic Diet (mNDI), Mediterranean diet (mMEDI) and Alternative Healthy Eating Index (mAHEI) with postmenopausal BC risk. Five Finnish cohorts were combined including 6374 postmenopausal women with dietary information. In all, 8-9 dietary components were aggregated in each index, higher total score indicating higher adherence to a healthy diet. Cox proportional hazards regression was used to estimate the combined hazard ratio (HR) and 95% confidence interval (CI) for BC risk. During an average 10-year follow-up period, 274 incident postmenopausal BC cases were diagnosed. In multivariable models, the HR for highest vs. lowest quintile of index was 0.67 (95 %CI 0.48-1.01) for mNDI, 0.88 (0.59-1.30) for mMEDI and 0.89 (0.60-1.32) for mAHEI. In this combined dataset, a borderline preventive finding of high adherence to mNDI on postmenopausal BC risk was found. Of the indices, mNDI was more based on the local food culture than the others. Although a healthy diet has beneficially been related to several chronic diseases, the link with the etiology of postmenopausal BC does not seem to be that obvious.

Incidence trends and risk factors of lung cancer in never smokers: Pooled analyses of seven cohorts.

The trends in incidence of lung cancer in never smokers are unclear as well as the significance of risk factors. We studied time trends in the incidence and risk factors of lung cancer in never smokers in Finland in a large, pooled cohort. We pooled data from seven Finnish health cohorts from the period between 1972 and 2015 with 106 193 never smokers. The harmonised risk factors included education, alcohol consumption, physical activity, height and BMI. We retrieved incident lung cancers from the nation-wide Finnish Cancer Registry. We estimated average annual percent change (AAPC) and the effects of risk factors on cause-specific hazard ratios (HRs) of lung cancer using Poisson regression. We detected 47 lung cancers in never smoking men (n = 31 859) and 155 in never smoking women (n = 74 334). The AAPC of lung cancer incidence was -3.30% (95% confidence interval [CI]: -5.68% to -0.88%, P = .009) in never smoking men and 0.00% (95% CI: -1.57% to 1.60%, P = .996) in never smoking women. Of the five studied risk factors only greater height in women had a statistically significant increased risk of lung cancer (multivariate HR = 1.84, 95%CI: 1.08 to 3.12). It is plausible that tobacco control measures focused on working places have reduced passive smoking among men more than among women, which could explain the declining trend in lung cancer incidence in never smoker men but not in never smoker women. As tobacco control measures have not been targeted to domestic environments, it is likely that women's exposure to passive smoking has continued longer.

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.