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Background: The effects of climate change, loss of pastureland to other land usage and presence of large carnivores are the main reasons for the increase in supplementary feeding of semi-domesticated reindeer (Rangifer tarandus tarandus) in Fennoscandia over the last decades. Feeding might expose reindeer to stress and increased animal-to-animal contact, leading to an increased risk of infectious disease transmission, such as infectious keratoconjunctivitis (IKC). As it can develop rapidly and be very painful, IKC is described as an important animal welfare concern and a potential source of economic loss. The aim of this study was to investigate the current presence of IKC and potential associations between IKC and supplementary feeding through an online questionnaire survey, distributed among reindeer herders in Norway and Sweden in 2021., Results: Seventy-six reindeer herders (33 from Norway and 43 from Sweden) responded to the questionnaire, representing 6% and 4% of the registered reindeer herding groups in Norway and Sweden, respectively. Infectious keratoconjunctivitis was common, with 54 (71%) of the 76 herders that responded having observed clinical signs during the past 10 years. These signs were mainly observed as increased lacrimation, causing "wet cheeks", but also as keratitis and conjunctivitis. Autumn and winter were the seasons in which IKC was observed most. The herders reported several measures, such as slaughter and isolation of affected reindeer, to counteract the spread of disease. The herding year 2019/2020 was associated with reports of outbreaks of IKC in herds as well as being the herding year where most herders (80%) had performed supplementary feeding. A significant association was found between IKC and feeding performed in an enclosure (odds ratio = 15.20), while feeding on free-range areas had a non-significant, negative, relationship with the appearance of IKC outbreaks (odds ratio = 0.29). Finally, there was a trend in the data suggesting that IKC affected calves especially., Conclusions: Infectious keratoconjunctivitis is a common disease, mainly observed in winter and autumn. It usually has mild to moderately severe clinical signs. Our results imply that IKC is associated with stress and feeding situations and that calves might be more susceptible than adults, however, this needs to be confirmed with further studies, preferably at an individual animal level., (© 2023. The Author(s).)

We investigated the association between polymorphism in the androgen receptor (AR) and vitamin D receptor (VDR) genes and breast cancer risk in a large population-based case-control study of genetically homogenous Swedish women. We successfully determined both AR CAG(n) and VDR A(n) genotype in 1,502 women with invasive breast cancer and in 1,510 control women. We did not find any associations between AR or VDR microsatellite lengths and breast cancer when we used a priori determined cutoffs (/=22 repeats for AR and /=19 for VDR) to define long and short alleles. There was statistically significant interaction between VDR genotype and parity, such that women with two short alleles had a halved risk for breast cancer, irrespective of parity, compared with nulliparous women with two long alleles. Homozygosity for the long VDR allele was associated with a more advanced clinical stage at diagnosis. In exploratory analyses, we determined cutoffs based on visual inspection of distributions of allele lengths among cases and controls and found that women carrying two alleles with <20 AR CAG(n) repeats had an increased risk for breast cancer, odds ratio of 1.67 (95% confidence interval, 1.17-2.38), compared with those with two alleles with >/=20 repeats. Women carrying two VDR alleles with <21 A(n) were also at an increased risk, odds ratio of 1.26 (95% confidence interval, 1.04-1.51). Our data do not support major roles for AR or VDR polymorphism as breast cancer risk factors. However, we did find an interaction between VDR genotype and parity that remains to be corroborated.

Adult obesity has been associated with an increased risk of post-menopausal breast cancer, but it is unclear whether this relationship reflects a causal role of obesity during childhood and adolescence, of weight gain during adult life or of adult obesity per se. In a population-based case-control study in all of Sweden, we included 3,345 (84% of all eligible) women aged 50-74 years with invasive breast cancer, and 3,454 (82% of all selected) controls of similar age. Mailed questionnaires and telephone interviews were used to collect detailed information on anthropometric measures. Odds ratios were estimated through multiple logistic regression. Women with the leanest somatotype at age 7 had about a 3-fold higher risk of breast cancer than the most obese (P for trend 0.0009). A suggested protective effect of a high body mass at age 18 and a detrimental influence of body mass 1 year prior to data collection largely reflected the effect of weight gain after age 18, a strong predictor of breast cancer risk. Among women at least 20 years post menopause, those who had gained 30 kg or more since age 18 had an odds ratio of 2.04 (95% confidence interval 1.20-3.48) of breast cancer compared with those who had maintained their weight unchanged. The effect of weight gain was unequivocal among non-users but not among users of hormone replacement therapy. Our findings have important implications, suggesting weight preservation as a means for prevention of post-menopausal breast cancer as well as a causal role of childhood body build in breast cancer etiology.

Possible associations between childbearing and the risk of brain cancer were explored in a case-control study "nested" within a large nationwide cohort defined by the Swedish Fertility Registry. Among women born between 1925-1975, 1,088 patients with meningiomas and 1,657 patients with gliomas were identified in the Swedish Cancer Registry. For every woman diagnosed with brain tumor, 5 age-matched controls were selected among those in the Fertility Registry. Relative risks were estimated by odds ratios from conditional logistic regression. Ever-parous women were at a reduced risk of glioma compared to nulliparous women, while parity was unrelated to meningioma risk. Age at first birth was unrelated to both meningioma and glioma risk. The gradient in risk between ever-parous and nulliparous women for gliomas, but not meningiomas, is difficult to explain biologically. A possible explanation is that pregnancy-induced alterations in androgen levels reduce the risk of glioma in parous women. Alternatively, childlessness may represent a marker of an occult glioma, negatively affecting fecundity. Overall, our present results do not support the notion that hormonal changes, or other physiological changes induced by childbearing, play an important role in the development of brain tumors.

The role of diet in the etiology of prostate cancer remains unclear, because results from several case-control and cohort studies on fat intake and risk of prostate cancer have been inconsistent; few of the studies have adjusted the results for caloric intake. To examine the relationship between energy, intake of several nutrients and risk of prostate cancer (all stages combined and advanced stages separately), we conducted a population-based case-control study in Orebro County, Sweden, from 1989 through 1994. A total of 526 patients with newly diagnosed prostate cancer and 536 controls, randomly selected from the population register and frequency-matched by age, were included in the analyses. Information about dietary intake was obtained from a self-administered semi-quantitative food frequency questionnaire. Odds ratios with 95% confidence intervals were estimated by unconditional logistic regression. In age-adjusted analyses, there were positive associations of prostate cancer (all stages combined) risk with total energy intake as well as intake of total fat (saturated and monounsaturated), protein, retinol and zinc. The positive association with energy intake was stronger for advanced cancer, with an excess risk of 70% for the highest quartile vs. the lowest. After adjustment for energy intake, there was no apparent association of prostate cancers (all stages combined) with any of the investigated nutrients. However, a weak positive association between intake of retinol and advanced cancer was observed. We conclude that our results provide some evidence that total energy intake is a risk factor for prostate cancer.

We evaluated the hypothesis that smoking increases the incidence of and mortality from prostate cancer. High-quality smoking information was collected in 1971-1975 in a nation-wide cohort of 135,006 male construction workers in Sweden. We achieved virtually complete follow-up through record linkages and ascertained as of December 1991 2,368 incident cases of prostate cancer and 709 deaths due to this disease. Rate ratios (RR) of prostate cancer incidence and mortality, with 95% confidence intervals (CI), were estimated in Poisson-based age-adjusted models, with amount and duration of smoking as independent variables. We found no convincing association between current smoking status, number of cigarettes smoked or years since onset and risk of prostatic cancer. The age-adjusted incidence RR among previous smokers was 1.09 and among current smokers 1.11 compared with non-smokers. Weak and inconsistent trends were seen with increasing number of cigarettes smoked per day and increasing duration among current smokers. Smokers of 15 or more cigarettes daily for at least 30 years experienced an incidence RR of 1.30. Mortality in ex-smokers was similar to that in never-smokers; it was, however, slightly increased among current smokers without any trend with amount smoked or duration. The weak and inconsistent associations between smoking and prostate cancer could easily have arisen due to bias or confounding. We therefore conclude that smoking is most likely not causally linked to the occurrence of prostate cancer.

We examined associations between lifestyle factors and subsequent risk of prostate cancer in a population-based case-control study. Information on smoking and alcohol habits, socioeconomic factors, marital status, family history, and sexual habits were obtained from a questionnaire and a face-to-face interview with 256 (74.6%) eligible patients and 252 (76.6%) selected controls, frequency matched by age and screened for prostate cancer with negative findings. Unconditional logistic regression was used to estimate the odds ratios (ORs). Risk was elevated among current smokers of cigarettes (OR, 1.8) and current users of hard liquor (OR, 1.4); however, the lack of dose-response trend for both of these exposures argues against a causal association. We found tentative evidence that early first intercourse, a larger number of sexual partners, and other indices of high sexual activity are associated with increased risk. Similarly, adult height, an indicator of nutrition during childhood and adolescence, was weakly positively associated with risk, although larger studies are needed to establish this link. Unmarried men had a lower risk than married men (OR, 0.3), and socioeconomic status did not appear to be strongly associated with prostate cancer. Men with a father who had prostate cancer had a more than 2-fold increased risk of prostate cancer, whereas those with a brother affected had about a 5-folk risk.

Background/aims: The risk of colorectal cancer increases in patients with ulcerative colitis, most markedly among young patients and/or those with extensive disease at onset. However, it is unknown whether individual risk can be predicted more precisely and whether cancer risk can be reduced by long-term treatment with sulfasalazine., Methods: In a population-based cohort of 3112 patients with ulcerative colitis, we compared 102 cases of colorectal cancer and 196 matched controls without cancer. Hospital records were used to abstract information on pharmacological therapy, disease activity, and extraintestinal manifestations. The relative risk (RR) of cancer was estimated by conditional logistic regression., Results: Pharmacological therapy, especially sulfasalazine, lasting at least 3 months was associated with a significant protective effect (RR, 0.38; 95% confidence interval [CI], 0.20-0.69) independent of disease activity. There was also a tendency to an independent protective effect for cigarette smoking (RR, 0.15; 95% CI, 0.02-1.25) and higher disease activity (RR, 0.80; 95% CI, 0.49-1.33)., Conclusions: The risk of colorectal cancer among patients with ulcerative colitis can be reduced through pharmacological therapy. This finding is consistent with the reports of a protective effect of aspirin among individuals in the general population.

A population-based case-control study of gastric cancer was conducted in areas with contrasting incidence rates in Sweden. Face-to-face interviews were carried out with 338 (74.1%) of all eligible cases and 679 (77.3%) of the selected controls. Consumption of selected nutrients during adolescence and 20 years prior to interview was estimated, together with life-time intake of vitamin supplements. Ascorbic acid and beta-carotene had an unequivocal protective effect, but alpha-tocopherol and nitrate were also negatively associated with gastric-cancer risk. In a multivariate analysis including all of these factors, only ascorbic acid remained a significant protective factor. The only macronutrient positively associated with the risk of gastric cancer was fat: intake 20 years prior to interview, but not during adolescence, was found to have a significant impact. Supplementation with vitamins almost halved the risk after adjustment for dietary intake of the corresponding vitamins. While the protective effect of vitamin C and beta-carotene could conceivably be ascribed to other agents in the diet, the strong negative association between supplementation with vitamin C and risk of gastric cancer supports the hypothesis of a protective role of this anti-oxidant.

Previous studies have provided conflicting information on the role of tobacco and alcohol in gastric carcinogenesis. A population-based case-control study with 338 histologically confirmed gastric-cancer cases and 679 control subjects was conducted. Information relating to life-time tobacco consumption, alcohol intake and diet during adolescence and 20 years before interview, and to socio-economic conditions was obtained through face-to-face interviews. Current cigarette smokers were found to have a greater risk than non-users of tobacco. The duration of cigarette or pipe smoking was positively associated with gastric-cancer risk. There was significant interaction between tobacco use and fruit consumption. High fruit intake was more protective among users of tobacco than among non-users, and the risk estimates associated with cigarette smoking were higher among those with low fruit consumption than among frequent fruit-eaters. Likewise, though to a lesser extent, vegetable intake interacted with tobacco use. Snuff dipping and alcohol intake was not associated with gastric-cancer risk. However, high alcohol intake tended to increase the risk associated with tobacco use. This study adds further support to the role of tobacco smoking in gastric carcinogenesis, and demonstrates that high intake of fruits and vegetables may be particularly beneficial in smokers.

Exposures early in life seem to play an important role in the development of gastric cancer, but their nature is not well understood. In a population-based case-control study, we examined weight, height and body-mass index (BMI) at the age of 20 as well as indices of socioeconomic conditions. Face-to-face interviews were conducted with 338 of 456 eligible histologically confirmed gastric cancer patients and 679 of 880 eligible control subjects, sampled from population registers and frequency matched by age and gender. Gastric cancer risk was negatively associated with height. Risk was positively, associated with weight at age 20 in both sexes. The highest BMI-quartile was associated with an increased risk. This association between BMI and risk was confined to BMI at age 20, and disappeared for BMI 20 years prior to interview. High socioeconomic status (SES) as well as long education carried a decreased risk of gastric cancer. Number of siblings was positively associated with risk. Factors related to short stature and high adolescent body weight are associated with an increased risk of gastric cancer, as is a high number of siblings. These factors may reflect influences of dietary patterns early in life.

A case-control study to evaluate risk factors of gastric cancer was carried out in areas with contrasting incidence rates in Sweden. Face-to-face interviews were conducted with 338 of 456 eligible histologically confirmed gastric-cancer cases and 669 of 880 eligible control subjects, sampled from population registers and frequency-matched by age and gender. We focused on 2 periods, adolescence and 20 years prior to interview. The association of gastric-cancer risk with dietary habits during adolescence were similar to that found for the period 20 years before interview; high consumption of wholemeal bread, fruit and vegetables was associated with reduced gastric-cancer risk. In addition, cheese, fish and tea had a protective effect during adolescence. Increased gastric-cancer risk was related to whole-milk consumption, but this association decreased substantially in a multivariate analysis including vegetables. There was a positive relationship between gastric-cancer risk and the age at which the interviewees started using refrigerators. This population-based study confirmed the protective effect of a high consumption of vegetables and fruit in the development of gastric cancer, but failed to find any association between intake of meat, sausage, cold cuts, liver, salt, coffee, the habit of frying, smoking or grilling foods, and risk of gastric cancer.

There is controversy about cancer mortality trends; some analyses show increasing mortality, but others suggest that rates are falling in the youngest age groups. We have investigated trends in cancer incidence in the whole of Sweden for the period 1958 to 1987. 837,085 cancer cases were registered during the period studied. Incidence rate patterns were studied by age-period-cohort modelling. The risk of cancer was higher for people born during the 1950s than for those born in 1873-82; for women the risk was doubled and for men it was trebled. Although the rate of increase slowed, it showed no sign of levelling off in the youngest birth cohorts. The frequency of smoking-related cancers increased greatly in both sexes, but such tumours could explain only part of the rise in total cancer. These trends predict a continuing rise in the incidence rate of cancer, and suggest a worrying pattern of increasing population exposure to carcinogenic influences.