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Biomedical subjects

O Nyrén

Publications and source records attributed to O Nyrén.

At least 19 recordsLinked to original sources
PubMed2006

Antibiotic treatment and risk of gastric cancer.

BACKGROUND/AIMS: Helicobacter pylori infection is undoubtedly an important risk factor for gastric cancer. It remains unclear however whether antibiotic treatment may prevent gastric cancer development. Our aim was to assess long term gastric cancer risks in historic cohorts of patients presumed to have been heavily exposed to antibiotics. SUBJECTS: Using the Swedish Inpatient Register, we identified 501 757 individuals discharged with any one of 10 selected infectious disease diagnoses between 1970 and 2003. METHODS: We counted person time and non-cardia gastric cancer occurrences through linkage to virtually complete population and health care registers. Standardised incidence ratios (SIRs) were calculated for comparisons with cancer incidence rates of the general population in Sweden. RESULTS: No reduction in gastric cancer risk was observed in the infectious disease cohort in total (SIR 1.08 (95% confidence intervals 1.00-1.17) or for any of the presumed antibiotic regimens. There were no clear trends towards decreasing risk with time of follow up, but the risk tended to fall with increasing age at first hospitalisation for the infection (p<0.04). CONCLUSIONS: Our results do not confirm earlier observational findings of a reduced risk of gastric cancer following exposure to heavy antibiotic treatment among hip replacement patients. Suboptimal drug regimens, inadequate timing of H pylori eradication, or insufficient follow up time may possibly explain the lack of association in this setting. Although our findings do not rule out the cancer preventive potential of H pylori eradication, they emphasise that detection of such an effect, if any, may require considerable efforts.

Adult↗
PubMed2006

A population-based binational register for monitoring long-term outcome and possible disease concordance among blood donors and recipients.

BACKGROUND AND OBJECTIVES: Even with appropriate donor deferrals and advanced screening tests, the risk of disease transmission through blood transfusion cannot be completely disregarded. Efficient monitoring of possible disease transmission between blood donors and recipients should be an important component of a comprehensive haemovigilance system. MATERIALS AND METHODS: We assembled the Scandinavian Donations and Transfusions (SCANDAT) database, with data on virtually all blood donors and recipients who have been registered at least once in any of the computerized local blood bank databases in Sweden and Denmark since the start of computerized registration in 1966. The records of these individuals, with their entire computerized donation and/or transfusion histories and all donor-component-recipient connections, were linked to nationwide population and health registers to attain essentially complete follow-up for up to 36 years regarding reproduction, hospital morbidity, cancer, and death. RESULTS: After data cleaning, the database contained 1,134,290 blood donors who contributed 15,091,280 records of donations and 1,311,079 recipients who received 11,693,844 transfusions. The data quality in the existing data sources was satisfactory. From the data obtained from local blood banks, 4.6%, 1.6%, and 6.4% of the person, donation, and transfusion records, respectively, had to be discarded after review of the legitimacy of recorded values, and comparisons with independent, external databases. CONCLUSION: It is possible to use existing computerized data, collected in routine health care, in haemovigilance systems for monitoring long-term outcome and disease concordance in blood donors and transfusion recipients.

Blood Donors↗
PubMed2006

On the natural course of oral lichen lesions in a Swedish population-based sample.

OBJECTIVES: The aim was to assess the natural course of oral lichen lesions (OLL) among unselected, non-consulting individuals. SUBJECTS AND METHODS: A cohort of 327 subjects with OLL, confirmed in 1973-1974 during a population-based survey in two Swedish municipalities, was followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 80 drawn from the 194 surviving subjects who still resided in the area in 1993-1995 was invited for interview and oral re-examination. RESULTS: At the end of follow-up, one case of oral cancer was detected, while 0.4 were expected. The overall mortality among subjects with OLL was not significantly different from that in the 15,817 OLL-free subjects who participated in the initial population based survey in 1973-1974. The lesion had disappeared in 14 (39%) of 36 re-examined subjects with white OLLs in 1973-1974, and four (11%) had transformed into red types. In the corresponding group of 19 with red forms initially, five (26%) had become lesion free and four (21%) had switched to white types. Although the cohort size does not permit firm conclusions regarding oral cancer risk, the natural course over up to 30 years appears to be benign in the great majority.

Adolescent↗
PubMed2006

Airborne occupational exposures and risk of oesophageal and cardia adenocarcinoma.

BACKGROUND: The reasons for the increasing incidence of and strong male predominance in patients with oesophageal and cardia adenocarcinoma remain unclear. The authors hypothesised that airborne occupational exposures in male dominated industries might contribute. METHODS: In a nationwide Swedish population based case control study, 189 and 262 cases of oesophageal and cardia adenocarcinoma respectively, 167 cases of oesophageal squamous cell carcinoma, and 820 frequency matched controls underwent personal interviews. Based on each study participant's lifetime occupational history the authors assessed cumulative airborne occupational exposure for 10 agents, analysed individually and combined, by a deterministic additive model including probability, frequency, and intensity. Furthermore, occupations and industries of longest duration were analysed. Relative risks were estimated by odds ratios (OR), with 95% confidence intervals (CI), using conditional logistic regression, adjusted for potential confounders. RESULTS: Tendencies of positive associations were found between high exposure to pesticides and risk of oesophageal (OR 2.3 (95% CI 0.9 to 5.7)) and cardia adenocarcinoma (OR 2.1 (95% CI 1.0 to 4.6)). Among workers highly exposed to particular agents, a tendency of an increased risk of oesophageal squamous cell carcinoma was found. There was a twofold increased risk of oesophageal squamous cell carcinoma among concrete and construction workers (OR 2.2 (95% CI 1.1 to 4.2)) and a nearly fourfold increased risk of cardia adenocarcinoma among workers within the motor vehicle industry (OR 3.9 (95% CI 1.5 to 10.4)). An increased risk of oesophageal squamous cell carcinoma (OR 3.9 (95% CI 1.2 to 12.5)), and a tendency of an increased risk of cardia adenocarcinoma (OR 2.8 (95% CI 0.9 to 8.5)), were identified among hotel and restaurant workers. CONCLUSIONS: Specific airborne occupational exposures do not seem to be of major importance in the aetiology of oesophageal or cardia adenocarcinoma and are unlikely to contribute to the increasing incidence or the male predominance.

Adenocarcinoma↗
PubMed2005

Elevated anal squamous cell carcinoma risk associated with benign inflammatory anal lesions.

BACKGROUND: The association between benign anal lesions and anal cancer is still unclear. Few data from large cohort studies are available. METHODS: We conducted a register based retrospective cohort study including 45,186 patients hospitalised for inflammatory anal lesions (anal fissures, fistulas, and perianal abscesses) as well as 79,808 haemorrhoid patients, from 1965 to 2002. Multiple record linkages identified all incident anal (squamous cell carcinoma only) and colorectal cancers through to 2002. Relative risk was estimated by standardised incidence ratio (SIR), the ratio of observed number of cases divided by that expected in the age, sex, and calendar year-matched general Swedish population. RESULTS: There was a distinct incidence peak in the first three years of follow up among patients with inflammatory lesions. SIR then levelled off at around 3 and remained at this level throughout follow up (SIR during years 3-37 of follow up was 3.3 (95% confidence interval 1.8-5.7)). A similar initial incidence peak was observed among haemorrhoid patients but was confined to the first year; SIR was 2.8 in the second year, and then it decreased further and was close to unity in the following years (SIR during years 3-37 was 1.3 (95% confidence interval 0.7-2.1)). Among inflammatory lesion and haemorrhoid patients, a significantly increased risk of colorectal cancer was observed only in the first year after hospitalisation. CONCLUSIONS: Inflammatory benign anal lesions are associated with a significantly increased long term risk of anal cancer. In contrast, haemorrhoids appear not to be a risk factor for this malignancy.

Adult↗
PubMed2004

Colorectal cancer screening with flexible sigmoidoscopy-participants' experiences and technical feasibility.

AIM: To evaluate tolerability and technical feasibility of colorectal cancer screening with flexible sigmoidoscopy. METHODS: One thousand men and women aged 59-61 years, randomly selected from the population register of Uppsala, Sweden, were invited by mail. After random allocation, half of them were called up by a nurse (group 1), while the other half were asked to call themselves (group 2) to book a sigmoidoscopy. After the examination, the participants anonymously answered a questionnaire about their subjective experiences. Endoscopists and their assisting nurse filled out structured forms documenting various technical aspects including an estimation of the subjects' discomfort. RESULTS: Four hundred and sixty-nine subjects participated. Mean intubation depth was 59 cm (range 28-60) and mean duration 5.8 min (range 2-23). On average, participants reported low degrees of discomfort and feeling of exposure, but 19 and 27% rated pain and distension, respectively, on the upper half of a visual analogue scale (VAS). Most subjects found the duration acceptable. Patient discomfort, as appraised by the endoscopists, was lower in men than in women, positively linked to duration of the procedure, but inversely associated with intubation distance. However, the overall differences between strata of participants were small. Among self-reported variables, group 1 and 2 differed significantly only with regard to 'other discomfort'. All but six subjects would accept a repeat examination. Failures, resulting in incomplete examinations, occurred in 14 subjects. CONCLUSIONS: Flexible sigmoidoscopy is generally well tolerated and technically feasible in screening for colorectal cancer. A more personalised invitation did not have any important effects on the subjective experience.

Colorectal Neoplasms↗
PubMed2003

No excess risk of colorectal cancer among alcoholics followed for up to 25 years.

We conducted a population-based retrospective cohort study among 179,398 Swedish patients hospitalised for alcoholism from 1970 to 1994, and found no excess risk for colorectal cancers, overall or at any anatomical subsite. Our findings challenge the hypothesis that alcohol intake is a risk factor for cancer of the large bowel.

Adult↗
PubMed2003

Helicobacter pylori: resurrection of the cancer link.

Helicobacter pylori is one of the most common pathogenic bacterial infections, colonizing an estimated half of all humans. In a subset of individuals, the infection leads to serious gastroduodenal disease such as peptic ulcers and gastric adenocarcinoma. The factors contributing to skewing this, in most cases benign, relationship into disease development are largely unknown. However, factors emanating from the bacterium, host and the environment have been shown to affect the risk for disease, although no factor can be singled out to be most important. The known factors are associated with affecting the risk of disease, and are not absolute. Virulence of H. pylori is affected by the existence and regulation of certain genes present in the bacterial population in a stomach. The effects of H. pylori on gastric cancer development have been challenged and the risk associated with infection with virulent (i.e. Cag PAI positive) H. pylori has likely been underestimated.

Adenocarcinoma↗
PubMed2003

Unexpected decrease with age of Helicobacter pylori seroprevalence among Swedish blood donors.

Blood donors are often used as proxies for the general population in studies of Helicobacter pylori epidemiology. Our aim was to test if the age-specific seroprevalence rates among blood donors match with the corresponding rates in a random population sample. This descriptive study was based on sera obtained from 3,502 blood donors representing all Swedish counties and cities. An age-stratified random population sample of 1,030 from Stockholm County served as comparison. Sera were analyzed by an in-house enzyme-linked immunosorbent assay for H. pylori immunoglobulin G antibodies. In the population sample, we found the expected increase with age in the seroprevalence of H. pylori infection. This was true also among young blood donors, while the prevalence-by-age curve showed a deflection downward among blood donors who are >/= 50 years of age. In this age group, the probability of being seropositive was reduced by 73% (95% confidence interval [CI], 63 to 81%) relative to the population sample. Overall, the adjusted odds ratio for H. pylori seropositivity among blood donors was decreased by 43% (95% CI, 28 to 55%). Thus, it appears that blood donors who are H. pylori seropositive selectively disappear from the blood donor cohort. We speculate that H. pylori-seropositive blood donors may tolerate repeated bleedings less well than do noninfected individuals and/or that the general well-being among those who are infected may be somewhat impaired. Our unexpected observation indicates that blood donors may be less suitable as proxies for the general population in analytic studies of H. pylori infection and that the underlying cause needs further study.

Adolescent↗
PubMed2003

Risk of cancers of the oesophagus and stomach by histology or subsite in patients hospitalised for pernicious anaemia.

BACKGROUND: Although pernicious anaemia is an established risk factor for stomach cancer, data by anatomical subsite are not available. Moreover, a previous suggestion of a link to increased risk of oesophageal cancer needs further exploration. METHODS: We followed 21 265 patients hospitalised for pernicious anaemia in Sweden from 1965 to 1999 for an average of 7.1 years. Standardised incidence ratio (SIR) adjusted for sex, age, and calendar year was used to estimate relative risk, using the Swedish nationwide cancer incidence rates as reference. RESULTS: Significant excess risks for squamous cell carcinoma of the oesophagus, and stomach cancer distal to the cardia, were observed in pernicious anaemia patients (SIR 3.3 (95% confidence interval (CI) 2.4-4.4); SIR 2.4 (95% CI 2.1-2.7), respectively). The excess risks increased with increasing follow up duration. Among distal stomach cancers, the most conspicuous excess risk was for carcinoid tumours (SIR 26.4 (95% CI 14.8-43.5)). Compared with the general population, no significant increased risk was observed for adenocarcinoma of the oesophagus (SIR 1.7 (95% CI 0.7-3.4)) or gastric cardia (SIR 1.2 (95%CI 0.6-2.0)). CONCLUSIONS: Achlorhydria following type A atrophic gastritis is associated with an elevated risk of adenocarcinoma of the non-cardia stomach, and surprisingly, with a risk of oesophageal squamous cell carcinoma. In contrast, no significant association, either positive or negative, was found with oesophageal or cardia adenocarcinoma. The mechanism for the observed increased risk of oesophageal squamous cell carcinoma warrants further study.

Adenocarcinoma↗
PubMed2002

Occupational physical activity and risk for prostate cancer in a nationwide cohort study in Sweden.

We investigated effects of occupational physical activity on relative risk for prostate cancer. From Swedish nationwide censuses in 1960 and 1970, we defined two cohorts of men whose occupational titles allowed classification of physical activity levels at work in 1960 (n=1,348,971) and in 1970 (n=1,377,629). A third cohort included only men whose jobs required a similar level of physical activity in both 1960 and 1970 (n=673,443). The incidence of prostate cancer between 1971 and 1989 was ascertained through record linkage to the Swedish Cancer Register. A total of 43,836, 28,702, and 19,670 prostate cancers, respectively, occurred in the three cohorts. In all three cohorts, the relative risk for prostate cancer increased with decreasing level of occupational physical activity (P<0.001), using Poisson regression. Among men with the same physical activity levels in 1960 and 1970, the rate ratio was 1.11 for men with sedentary jobs as compared with those whose jobs had very high/high activity levels after adjustment for age at follow-up, calendar year of follow-up and place of residence (95% CI 1.05-1.17; P for trend <0.001). There was no association between occupational activity and prostate cancer mortality. Since we had no data on other potential risk factors the observed associations for both incidence and mortality might have been confounded. Further studies are needed to better understand the potential role of physical activity for prostate cancer.

Adult↗
PubMed2002

Does the method of Helicobacter pylori detection influence the association with gastric cancer risk?

BACKGROUND: The exact role of Helicobacter pylori as a causative agent of gastric cancer is still under debate. The aim of this study was to determine how the use of different diagnostic methods for detection of H. pylori influences the measures of prevalence of the infection and thus the association with risk of gastric adenocarcinoma. METHODS: We included 72 cases and 324 controls in an endoscopy clinic-based matched case-control study. Culture of H. pylori and immunohistochemical staining were performed on gastric biopsies. Serum samples were tested for H. pylori IgG by conventional ELISA and by immunoblotting. RESULTS: The overall prevalence of H. pylori was 68% based on all 4 diagnostic methods, 79% in the cases and 66% in the controls. Highest agreement, 91%, was observed between culture and immunohistochemistry with a Kappa value of 0.81. Immunoblotting detected the highest number of H. pylori-positive subjects in both cases and controls. The association of H. pylori positivity with gastric cancer was generally weaker and statistically non-significant using culture and immunohistochemistry compared with the serological tests, of which IgG ELISA yielded the higher odds ratio (OR 2.5, 95% confidence interval 1.4-4.4). CONCLUSION: The study shows that relative risk estimates for the association between H. pylori and gastric cancer risk are to some extent determined by the diagnostic method used to detect H. pylori infection.

Adenocarcinoma↗
PubMed2002

Alcohol abuse and the risk of pancreatic cancer.

BACKGROUND: Although most epidemiological studies do not support a role for alcohol in the aetiology of pancreatic cancer, an increased risk among heavy drinkers cannot be excluded. METHODS: In a retrospective cohort based on the Swedish Inpatient Register, we analysed the risk of pancreatic cancer among patients admitted to hospital for alcoholism (n=178 688), alcoholic chronic pancreatitis (n=3500), non-alcoholic chronic pancreatitis (n=4952), alcoholic liver cirrhosis (n=13 553), or non-alcoholic liver cirrhosis (n=7057) from 1965 to 1994. Follow up through to 1995 was accomplished by linkage to nationwide registers. Standardised incidence ratios (SIRs) express the relative risks by taking the general Swedish population as reference. To minimise the possible influence of selection bias, we excluded the first year observations. RESULTS: Alcoholics had only a modest 40% excess risk of pancreatic cancer (SIR 1.4, 95% confidence interval (CI) 1.2-1.5). Overrepresented smokers among alcoholics might confound a true SIR of unity among alcoholics to approximately 1.4. SIR among alcoholic chronic pancreatitis patients (2.2, 95% CI 0.9-4.5) was considerably lower than that among non-alcoholic chronic pancreatitis patients (8.7, 95% CI 6.8-10.9), and decreased with increasing duration of follow up in both groups, indicating that most of the excess might be explained by reversed causation from undiagnosed cancers. Among patients with alcoholic liver cirrhosis, the increased risk of pancreatic cancer was also moderate (SIR 1.9, 95% CI 1.3-2.8) while no significant excess risk was found among non-alcoholic liver cirrhosis patients (SIR 1.2, 95% CI 0.6-2.2). CONCLUSIONS: The excess risk for pancreatic cancer among alcoholics is small and could conceivably be attributed to confounding by smoking.

Adult↗
PubMed2001

Acetaminophen, aspirin, and chronic renal failure.

BACKGROUND: Several epidemiologic studies have demonstrated an association between heavy consumption of nonnarcotic analgesics and the occurrence of chronic renal failure, but it is unclear which is the cause and which is the effect METHODS: In a nationwide, population-based, case-control study of early-stage chronic renal failure in Sweden, face-to-face interviews were conducted with 926 patients with newly diagnosed renal failure and 998 control subjects, of whom 918 and 980, respectively, had complete data. We used logistic-regression models to estimate the relative risks of disease-specific types of chronic renal failure associated with the use of various analgesics RESULTS: Aspirin and acetaminophen were used regularly by 37 percent and 25 percent, respectively, of the patients with renal failure and by 19 percent and 12 percent, respectively, of the controls. Regular use of either drug in the absence of the other was associated with an increase by a factor of 2.5 in the risk of chronic renal failure from any cause. The relative risks rose with increasing cumulative lifetime doses, rose more consistently with acetaminophen use than with aspirin use, and were increased for most disease-specific types of chronic renal failure. When we disregarded the recent use of analgesics, which could have occurred in response to antecedents of renal disease, the associations were only slightly attenuated CONCLUSIONS: Our results are consistent with the existence of exacerbating effects of acetaminophen and aspirin on chronic renal failure. However, we cannot rule out the possibility of bias due to the triggering of analgesic consumption by predisposing conditions.

Acetaminophen↗
PubMed2001

Risk of adenocarcinomas of the oesophagus and gastric cardia in patients hospitalized for asthma.

In the first cohort study of the question we followed 92 986 (42 663 men and 50 323 women) adult patients hospitalized for asthma in Sweden from 1965 to 1994 for an average of 8.5 years to evaluate their risk of oesophageal and gastric cardia adenocarcinoma. Standardized incidence ratio (SIR) adjusted for gender, age and calendar year was used to estimate relative risk, using the Swedish nationwide cancer incidence rates as reference. Asthmatic patients overall had a moderately elevated risk for oesophageal adenocarcinoma (SIR = 1.5, 95% confidence interval CI, 0.9-2.5) and gastric cardia cancer (SIR = 1.4, 95% CI, 1.0-1.9). However, the excess risks were largely confined to asthmatic patients who also had a discharge record of gastro-oesophageal reflux (SIR = 7.5, 95% CI, 1.6-22.0 and SIR = 7.1, 95% CI, 3.1-14.0, respectively). No significant excess risk for oesophageal squamous-cell carcinoma or distal stomach cancer was observed. In conclusion, asthma is associated with a moderately elevated risk of developing oesophageal or gastric cardia adenocarcinoma. Special clinical vigilance vis-à-vis gastro-esophageal cancers seems unwarranted in asthmatic patients, but may be appropriate in those with clinically manifest gastro-oesophageal reflux.

Adenocarcinoma↗
PubMed2001

Nationwide study of cancer risk among hip replacement patients in Sweden.

BACKGROUND: Orthopedic implants and their fixatives contain materials with carcinogenic potential. Whether these implants are linked to subsequent cancer development remains unknown, mainly because large-scale, long-term follow-up data are scarce. METHODS: We conducted a nationwide cohort study in Sweden to examine cancer incidence among 116,727 patients who underwent hip replacement surgery during the period from 1965 through 1994. Through record linkage to the Swedish Cancer Register, we identified all incident cancers through 1995 in this population (693,954 person-years of observation). For each cancer type, the observed number of cases was divided by that expected in the general Swedish population to produce standardized incidence ratios (SIRs). RESULTS: Relative to the general population, the cohort had no overall cancer excess (SIR = 1.01; 95% confidence interval [CI] = 0.99 to 1.03). However, we observed elevated SIRs for prostate cancer (SIR = 1.16; 95% CI = 1.11 to 1.22) and melanoma (SIR = 1.15; 95% CI = 1.01 to 1.30) and a reduction in stomach cancer risk (SIR = 0.83; 95% CI = 0.75 to 0.92). Long-term follow-up (>or=15 years) revealed an excess of multiple myeloma (SIR = 1.86; 95% CI = 1.01 to 3.11) and a statistically nonsignificant increase in bladder cancer (SIR = 1.42; 95% CI = 0.98 to 1.99). There was no material increase in risk for bone or connective tissue cancer for either men or women in any follow-up period. CONCLUSIONS: In this, the largest study to date, hip implant patients had similar rates of most types of cancer to those in the general population. Although the excesses of melanoma, multiple myeloma, and prostate and bladder cancers may be due to chance, confounding, or detection bias and should be interpreted cautiously, they warrant further investigation because of the ever-increasing use of hip implants at younger ages.

Aged↗
PubMed2001

Risk of cancers of the lung, head and neck in patients hospitalized for alcoholism in Sweden.

Alcoholic patients are at increased risk of cancers of the head and neck but little information is available on the magnitude of the risk for specific sites and for different histological types. We followed 182 667 patients with a hospital discharge diagnosis of alcoholism during 1965-1994, for an average of 10.2 years. We compared their incidence of site- and histological type-specific cancers of the oral cavity, pharynx, larynx and lung with that of the national population. The standardized incidence ratio (SIR) of cancer of the oral cavity and pharynx was 5.33 (95% confidence interval [CI] 5.04-5.64, based on 1207 cases). The SIRs of laryngeal and lung cancer were 4.21 (95% Cl 3.78-4.68, 347 cases) and 2.40 (2.29-2.51, 1880 cases), respectively. The SIR was highest for cancers of the hypopharynx, floor of the mouth, mesopharynx and base of the tongue. The relative excess of lung cancer was similar for squamous cell carcinoma and adenocarcinoma. Low age at first hospitalization was associated with higher SIRs for all sites under study. 25 years after first hospitalization for alcoholism, the cumulative probability of developing a lung cancer was in the order of 5%, for oral and pharyngeal cancer it was 2.5%, and for oesophageal or laryngeal cancer 1% each. Our study shows that the risk of head and neck cancer among heavy drinkers is highest for sites in direct contact with alcohol. The high risk of head and neck neoplasms may justify specific medical attention.

Age Distribution↗