Biomedical subjects

J H Olsen

Publications and source records attributed to J H Olsen.

At least 55 records · Page 3Linked to original sources

PubMed2001

Appendectomy and subsequent risk of inflammatory bowel diseases.

BACKGROUND: Case-control studies have reported an inverse relationship between appendectomy and the risk of ulcerative colitis, but the association has not been confirmed in prospective studies. METHODS: Using national hospital discharge registry data in Denmark, the authors followed up 154,434 patients who underwent appendectomy during the period 1977 to 1989 to investigate whether they had subsequent hospitalizations for ulcerative colitis and Crohn's disease. Ratios of observed-to-expected first hospitalizations for inflammatory bowel diseases served as measures of the relative risk (RR). RESULTS: Hospitalization for ulcerative colitis occurred in 84 patients who had appendectomies versus 97.0 expected (RR = 0.87; 95% CI, 0.69-1.07). RRs were not significantly reduced in subgroups defined by sex, age, time since appendectomy, calendar period, or cause of appendectomy. Hospitalization for Crohn's disease occurred in excess (RR = 2.88; 95% CI, 2.45-3.39; n = 150), notably in the first year after appendectomy (RR = 10.83; 95% CI, 8.49-13.62; n = 73); but after 5 years, the RR was not significantly elevated. CONCLUSIONS: This large population-based cohort study failed to support a significant inverse association between appendectomy and ulcerative colitis risk in the first decade after the operation. The excess of Crohn's disease shortly after appendectomy most likely reflects differential diagnostic problems in patients newly presenting with abdominal pain.

Adult↗

PubMed2001

Connective tissue disease after hip and knee implant surgery.

OBJECTIVE: To increase the knowledge of the long-term effects of artificial hip and knee joint implants. METHODS: The study groups consisted of 24,636 patients with osteoarthritis who underwent hip implant surgery and 5,221 who received knee implants during 1977-89. The post-implant rate of hospitalization for connective tissue disease (CTD) was compared with the rate in the general population of Denmark and with that among osteoarthritis patients without implant surgery. RESULTS: The rates of hospitalization for CTD were higher than the background level among both hip and knee implant patients with osteoarthritis, whereas the comparison with non-implanted osteoarthritis patients revealed that the hospitalization rate for CTD was reduced after hip implant surgery, but increased after knee implant surgery. CONCLUSION: Since the materials used in hip and knee implants in Denmark are not substantially different, these results are unlikely to reflect an implant effect but rather the selection criteria of referral for implant surgery.

Aged↗

PubMed2001

Capsular contracture after cosmetic breast implant surgery in Denmark.

The authors investigated the association between the occurrence of capsular contracture and implant and patient characteristics. All women with breast implants from 1977 to 1997 were identified from the files of two private plastic surgery clinics in Denmark. Information on implant and patient characteristics, surgical procedure, and complications was obtained through medical records and self-administered questionnaires. Of 754 women (1,572 implants), average age at implantation was 32 years. Implant types were silicone double lumen, textured, 31.2%; silicone single lumen, textured, 27.8%; silicone single lumen, smooth, 24.5%; silicone double lumen, smooth, 0.8%; and other or missing, 15.7%. Placement was submuscular for more than 90% of implants. Capsular contracture occurred in 7.9% of implanted breasts, on an average of 621 days postoperatively, with 51.6% being bilateral. Overall, 66.1% of capsular contractures were recorded within the first 12 months postoperatively, and 79.0% were recorded within 24 months. Double-lumen implants were associated with a significantly (p < 0.01) reduced occurrence of capsular contracture. In summary, capsular contracture typically occurs within the first 2 years of implantation. Host factors may be important because more than half the capsular contractures in the current study were bilateral. Occurrence of capsular contracture did not appear to be associated with implant surface or placement, occurrence of local complications, or patient characteristics, although these findings should be interpreted cautiously.

Adult↗

PubMed2001

Cancer incidence among Danish workers exposed to trichloroethylene.

Human evidence regarding the carcinogenicity of the animal carcinogen trichloroethylene (TCE) is limited. We evaluated cancer occurrence among 803 Danish workers exposed to TCE, using historical files of individual air and urinary measurements of TCE-exposure. The standardized incidence ratio (SIR) for cancer overall was close to unity for both men and women who were exposed to TCE. Men had significantly elevated SIRs for non-Hodgkin's lymphoma (SIR = 3.5; n = 8) and cancer of the esophagus (SIR = 4.2; n = 6). Among women, the SIR for cervical cancer was significantly increased (SIR = 3.8; n = 4). No clear dose-response relationship appeared for any of these cancers. We found no increased risk for kidney cancer. In summary, we found no overall increase in cancer risk among TCE-exposed workers in Denmark. For those cancer sites where excesses were noted, the small numbers of observed cases and the lack of dose-related effects hinder etiological conclusions.

Denmark↗

PubMed2001

BRCA1 and BRCA2 mutation status and cancer family history of Danish women affected with multifocal or bilateral breast cancer at a young age.

INTRODUCTION: A small fraction of breast cancer is the result of germline mutations in the BRCA1 and BRCA2 cancer susceptibility genes. Mutation carriers frequently have a positive family history of breast and ovarian cancer, are often diagnosed at a young age, and may have a higher incidence of double or multiple primary breast tumours than breast cancer patients in general. OBJECTIVES: To estimate the prevalence and spectrum of BRCA1 and BRCA2 mutations in young Danish patients affected with bilateral or multifocal breast cancer and to determine the relationship of mutation status to family history of cancer. SUBJECTS: From the files of the Danish Breast Cancer Cooperative Group (DBCG), we selected 119 breast cancer patients diagnosed before the age of 46 years with either bilateral (n=59) or multifocal (n=61) disease. METHODS: DNA from the subjects was screened for BRCA1 and BRCA2 mutations using single strand conformation analysis (SSCA) and the protein truncation test (PTT). Observed and expected cancer incidence in first degree relatives of the patients was estimated using data from the Danish Cancer Registry. RESULTS: Twenty four mutation carriers were identified (20%), of whom 13 had a BRCA1 mutation and 11 carried a BRCA2 mutation. Two mutations in BRCA1 were found repeatedly in the material and accounted for seven of the 24 (29%) mutation carriers. The mutation frequency was about equal in patients with bilateral (22%) and multifocal breast cancer (18%). The incidence of breast and ovarian cancer was greatly increased in first degree relatives of BRCA1 and BRCA2 mutation carriers, but to a much lesser degree in relatives of non-carriers. An increased risk of cancer was also noted in brothers of non-carriers. CONCLUSIONS: A relatively broad spectrum of germline mutations was observed in BRCA1 and BRCA2 and most of the mutations are present in other populations. Our results indicate that a diagnosis of bilateral and multifocal breast cancer is predictive of BRCA1 and BRCA2 mutation status, particularly when combined with information on the patients' age at diagnosis and family history of breast/ovarian cancer.

Adult↗

PubMed2001

Mycobacterium avium subsp. paratuberculosis infection in an addax (Addax nasomaculatus).

Mycobacterium avium subsp. paratuberculosis was cultured from a single fecal sample collected from a 10-yr-old, captive-bred male addax (Addax nasomaculatus). Attempts to confirm infection with additional fecal cultures, serology, semen culture, and tissue biopsy were unsuccessful. There were no gross lesions on necropsy. On histopathology there were neither acid-fast organisms nor microscopic changes suggestive of active or clinical Johne's disease. Mycobacterium avium subsp. paratuberculosis was isolated from four organ tissues: ileum, jejunum, colon, and mesenteric lymph node.

Animals↗

PubMed2001

Hospitalisation for upper gastrointestinal bleeding associated with use of oral anticoagulants.

The incidence of hospitalisation for upper GI bleeding with use of oral anticoagulants (OA) alone or in combination with other drugs was examined in a cohort of 4,204 users of OA, identified through record linkage between a population-based prescription database and a hospital discharge registry in Denmark, and compared with the incidence in the general population not exposed to OA. The standardised incidence ratio (SIR) was 2.8 (95% CI = 1.6-4.5) for use of OA alone. SIRs tended to be higher for use of OA combined with acetaminophen alone (4.4, 95% CI = 1.2-11.4), non-aspirin NSAIDs alone (8.0, 95% CI = 2.1 to 20.4) or aspirin/corticosteroids alone (3.8, 95% CI = 0.8-11.0), respectively. These results indicate that use of OA is associated with a significantly increased risk of upper GI bleeding, with still higher risks associated with the concomitant use of other medications including acetaminophen. Further research is needed to clarify the extent to which drugs interacting with oral anticoagulants may cause GI bleeding and the mechanisms through which these associations operate.

Acetaminophen↗

PubMed2000

Prognosis of cancers associated with venous thromboembolism.

BACKGROUND: Little is known about the prognosis of cancer discovered during or after an episode of venous thromboembolism. METHODS: We linked the Danish National Registry of Patients, the Danish Cancer Registry, and the Danish Mortality Files to obtain data on the survival of patients who received a diagnosis of cancer at the same time as or after an episode of venous thromboembolism. Their survival was compared with that of patients with cancer who did not have venous thromboembolism (control patients), who were matched in terms of type of cancer, age, sex, and year of diagnosis. RESULTS: Of 668 patients who had cancer at the time of an episode of deep venous thromboembolism, 44.0 percent of those with data on the spread of disease (563 patients) had distant metastasis, as compared with 35.1 percent of 5371 control patients with data on spread (prevalence ratio, 1.26; 95 percent confidence interval, 1.13 to 1.40). In the group with cancer at the time of venous thromboembolism, the one-year survival rate was 12 percent, as compared with 36 percent in the control group (P<0.001), and the mortality ratio for the entire follow-up period was 2.20 (95 percent confidence interval, 2.05 to 2.40). Patients in whom cancer was diagnosed within one year after an episode of venous thromboembolism had a slightly increased risk of distant metastasis at the time of the diagnosis (prevalence ratio, 1.23 [95 percent confidence interval, 1.08 to 1.40]) and a relatively low rate of survival at one year (38 percent, vs. 47 percent in the control group; P<0.001). CONCLUSIONS: Cancer diagnosed at the same time as or within one year after an episode of venous thromboembolism is associated with an advanced stage of cancer and a poor prognosis.

Case-Control Studies↗

PubMed2000

Second malignant neoplasms after cancer in childhood and adolescence: a population-based case-control study in the 5 Nordic countries. The Nordic Society for Pediatric Hematology and Oncology. The Association of the Nordic Cancer Registries.

Our purpose was to assess the risk of developing a second malignant neoplasm (SMN) after cancer in childhood and adolescence associated with different treatment modalities. Our investigation was performed as a nested case-control study within a Nordic cohort of 25,120 patients younger than 20 years old at first malignant neoplasm (FMN) diagnosed in 1960 through 1987. SMNs were diagnosed in 1960 through 1991. For each case of SMN, 3 controls were sampled, matched by sex, age, calendar year of diagnosis and length of follow-up. For the final analysis, there were 234 cases and 678 controls. Relative risks (RRs) of various exposures were estimated by means of conditional logistic regression, with non-exposed as the reference. The RR of developing SMN in the radiated volume was 4.3 (95% confidence interval 3.0-6.2). The risk was highest in children diagnosed before the age of 5 years; it increased with the dose of radiation and with increasing follow-up time after FMN. Chemotherapy alone was not associated with an increased RR, but it significantly potentiated the effect of radiotherapy. RRs were unchanged between the periods 1960-1973 and 1974-1987, and since the use of chemotherapy increased in the latter period, the number of SMNs may increase. Hereditary factors were important for the occurrence of SMN independently of therapy. We conclude that radiation was the most important treatment-related risk factor for the development of SMN. Chemotherapy appeared to play only an accessory role during the study period, potentiating the carcinogenic effect of radiotherapy.

Adolescent↗

PubMed2000

Cancer occurrence after cosmetic breast implantation in Denmark.

Most studies on cancer incidence after breast implantation have focused on breast cancer, while the risk of cancers at other sites has been less well investigated. We examined cancer incidence among 1,653 women who underwent cosmetic breast implant surgery at private clinics of plastic surgery in Denmark and 1,736 women attending the same clinics for other reasons during the period 1973-1995. Furthermore, we updated previously reported results among 1,114 women who received implants for cosmetic indications at public hospitals. All women were followed for cancer through the Danish Cancer Registry. In comparison with the general female population, the overall standardized incidence ratio (SIR) for cancer among women who received implants in private clinics was 1.65 [95% confidence interval (CI) = 1.17-2.27]. This elevated SIR reflected increased incidence ratios for almost all major cancer sites; however, only for non-melanoma skin cancer was there an excess of more than 2 cases. No significant excess of cancer was observed among women who received implants in public hospitals (SIR = 1.10, 95% CI = 0.76-1.52) or among women attending the private clinics for other problems (SIR = 1.10, 95% CI = 0.78-1.52). The SIRs for breast cancer after breast implantation were 1.1 (95% CI = 0.5-2.2) among private clinic patients and 0.9 (95% CI = 0.4-1.7) among public hospital patients. The overall findings of these 2 implant cohorts and results from other investigations suggest that cancer risk is probably not increased among women receiving cosmetic breast implants. The inconsistent results for private clinics and public hospitals are likely related to selection bias and confounding among the private clinic patients, but our data did not permit exploration of these possibilities. Further research into the determinants of these inconsistencies is warranted.

Adolescent↗

PubMed2000

Risk of testicular cancer in men with abnormal semen characteristics: cohort study.

OBJECTIVE: To explore the associations between semen characteristics and subsequent risk of testicular cancer. DESIGN: Cohort study. PARTICIPANTS: 32 442 men who had a semen analysis done at the Sperm Analysis Laboratory in Copenhagen during 1963-95. MAIN OUTCOME MEASURE: Standardised incidence ratios of testicular cancer compared with total population of Danish men. RESULTS: Men in couples with fertility problems were more likely to develop testicular cancer than other men (89 cases, standardised incidence ratio 1.6; 95% confidence interval 1.3 to 1.9). The risk was relatively constant with increasing time between semen analysis and cancer diagnosis. Analysis according to specific semen characteristics showed that low semen concentration (standardised incidence ratio 2.3), poor motility of the spermatozoa (2.5), and high proportion of morphologically abnormal spermatozoa (3.0) were all associated with an increased risk of testicular cancer. The only other cancer group that showed increased incidence was "peritoneum and other digestive organs" (six cases; 3.7, 1.3 to 8.0). Of these, two cases were probably and two cases were possibly extragonadal germ cell tumours. CONCLUSIONS: The results point towards the existence of common aetiological factors for low semen quality and testicular cancer. Low semen quality may also be associated with increased incidence of extragonadal germ cell tumours.

Adult↗

PubMed2000

Cancer risk and mortality in users of calcium channel blockers. A cohort study.

BACKGROUND: Data regarding the association between the use of calcium channel blockers and cancer risk have been conflicting. In the current study, the authors examined the cancer risk and mortality in users of calcium channel blockers in North Jutland County, Denmark. METHODS: The authors conducted a cohort study using record linkage between a population-based prescription database, the Danish Cancer Registry, and the Danish Death Registry including 23, 167 users of calcium channel blockers who received >/=2 prescriptions between January 1, 1989 and December 31, 1995. The authors calculated the standardized incidence ratios and standard mortality ratios for cancer, along with corresponding 95% confidence intervals (95% CI). RESULTS: Overall, 967 incident cases of cancer occurred, resulting in a standardized incidence ratio of 1.04 (95% CI, 0.98-1.11). There was a slightly elevated nonsignificant risk of tobacco-related cancer. No increased risk of breast or colon carcinoma was observed. The cancer mortality was close to that expected in the background population (standardized mortality ratio of 0.97; 95% CI, 0.89-1.04). CONCLUSIONS: This large-scale, population-based cohort study adds to the increasing evidence indicating no substantial association between the use of calcium channel blockers and the incidence rate of cancer or cancer mortality.

Adolescent↗

PubMed2000

[Incidence of cancer after primary deep venous thrombosis or pulmonary embolism].

We report a nationwide study based on a cohort of patients with a thromboembolic event (TE) defined as deep venous thrombosis and/or pulmonary embolism identified from the Danish National Registry of Patients from 1977 to 1993. Cancer occurrence in the cohort was determined by linkage to the Danish Cancer Registry. Expected number of cancer cases was estimated from age, sex and site-specific incidence rates. A total of 26,653 TE-cases were identified. We observed 1737 cases of cancer versus 1371 expected (SIR 1.3; 95% CI, 1.21 to 1.33). The risk was particularly high during the first months of follow-up, but declined rapidly hereafter to a constant level slightly above 1.0 one year after the TE. Forty percent of patients diagnosed with cancer within one year from the hospitalization for TE had distant metastases at the time of cancer diagnosis. The observed risk pattern provides evidence that most often a preclinical cancer gives rise to a subsequent TE. An aggressive search for hidden cancer in patients with TE is not warranted.

Adult↗

PubMed2000

[Screening for lung cancer. Promising results with low-dose CT].

Low-radiation-dose computed tomography (low-dose CT) is a new, promising technology presently used in screening for lung cancer in some medical centres in the USA and Japan. The three population-based studies of the efficacy of screening with low-dose CT published to date all show that more than 85% of the lung cancers detected by low-dose CT are in stage I, offering improved possibility for curative treatment. The number of false positive scans, was up to 20%. The radiation dose per low-dose CT scan was approximately the dose of a mammography (1 mSv). In two studies, low-dose CT failed to detect some centrally located tumours. None of the studies are capable of evaluating changes in lung cancer mortality in a screened population compared to those of a control population. There is, therefore, a need for further assessments of positive as well as negative effects of population-based screening with low-dose CT.

Evaluation Studies as Topic↗

PubMed2000

Cancer risk in patients with monoclonal gammopathy of undetermined significance.

To assess the cancer risk of monoclonal gammopathy of undetermined significance (MGUS) we identified 1229 cases of MGUS in the period 1978 to 1993. Data on cancer occurrence in the MGUS cohort were obtained from the Danish Cancer Registry. The expected numbers of cancer cases were calculated from age-, sex-, county-, and period-specific cancer incidence rates. In the MGUS cohort 64 new cancers with a known association with M-components were diagnosed versus 5.0 expected giving a standardized incidence ratio (SIR) of 12.9 (95% confidence interval, 9.9-16.5). The relative risks of developing multiple myeloma (SIR 34.3), Waldenström's macroglobulinemia (SIR 63.8), and non-Hodgkin's lymphoma (SIR 5.9) were significantly increased and independent of time passed from detection of the M-component. The relative risk of chronic lymphocytic leukemia was not significantly increased, SIR 2.7 (0.5-7. 7). Among cancer sites without known association with M-components 141 cases were observed versus 94.6 expected giving a SIR of 1.5 (1. 3-1.8). This enhanced risk was seen for several non-hematological cancer sites but for most cancer sites the risk was dependent on time passed from detection of the M-component, indicating a bias rather than a causal role of MGUS.

Adolescent↗

PubMed2000

Characterization of ATM mutations in 41 Nordic families with ataxia telangiectasia.

The Ataxia Telangiectasia Mutation (ATM) gene is mutated in the rare recessive syndrome Ataxia Telangiectasia (AT), which is characterized by cerebellar degeneration, immunodeficiency, and cancer predisposition. In this study, 41 AT families from Denmark, Finland, Norway, and Sweden were screened for ATM mutations. The protein truncation test (PTT), fragment length and heteroduplex analyses of large (0.8-1.2 kb) cDNA fragments were used. In total, 67 of 82 (82%) of the disease-causing alleles were characterized. Thirty-seven unique mutations were detected of which 25 have not previously been reported. The mutations had five different consequences for the ATM transcript: mutations affecting splicing (43%); frameshift mutations (32%); nonsense mutations (16%); small in-frame deletions (5%); and one double substitution (3%). In 28 of the probands mutations were found in both alleles, in 11 of the probands only one mutated allele was detected, and no mutations were detected in two Finnish probands. One-third of the probands (13) were homozygous, whereas the majority of the probands (26) were compound heterozygote with at least one identified allele. Ten alleles were found more than once; one Norwegian founder mutation constituted 57% of the Norwegian alleles. Several sequence variants were identified, none of them likely to be disease-causing. Some of them even involved partial skipping of exons, leading to subsequent truncation of the ATM protein.

Alternative Splicing↗

PubMed2000

Incidence of lung cancer in Denmark: historical and actual status.

This is a registry-based analysis of 97,281 lung cancer patients diagnosed in Denmark during the period 1943-1994. The development of lung cancer incidence in Denmark in the study period is described and this information is used to predict the future trends in lung cancer in Denmark. Since 1960, lung cancer has been the most frequent type of cancer in Danish men, excluding skin cancer. The incidence in men reached its maximum in 1985, when it was 100 new cases per 100,000 inhabitants, whereafter the incidence began to level off and was 83 per 100,000 inhabitants in 1994. During the study period, the incidence of lung cancer in Danish women was somewhat lower than in men. The incidence in women has been steadily increasing since 1960 by approximately 20% per each 5-year period, and was 46 per 100,000 inhabitants in 1994. Adenocarcinoma is the most frequent histological subtype in women and the only subtype increasing in incidence in men. Taking the actual development into account, the incidence of lung cancer will continue to fall among men and rise among women, leading to a reversal of the classical gender ratio in about 15 years.

Adenocarcinoma↗

PubMed2000

Crohn's disease and cancer risk (Denmark).

OBJECTIVES: The large number of studies of intestinal cancer among patients with Crohn's disease have provided inconsistent risk estimates in regard to risk of both colorectal and small intestinal cancer. We investigated incidence of cancer among Crohn's disease patients in comparison with the incidence in the general population of Denmark. METHODS: From the Danish National Registry of Patients we identified 2645 patients who had been hospitalized with Crohn's disease during 1977-1989. Cancer incidence for up to 17 years was determined in the cohort and compared to an expected number derived from national cancer incidence rates. RESULTS: The 15 observed cases of colorectal cancer were close to the expected number of 13.1 (SIR = 1.1; 95% CI 0.6-1.9), whereas the five cases of small intestinal cancer (three adenocarcinomas and two carcinoids) observed corresponded to an 18-fold increased risk (SIR = 17.9; 95% CI 5.8-42). CONCLUSIONS: A potential excess of colorectal cancer among subgroups of patients with Crohn's disease was not detectable in the overall risk estimate for colorectal cancer. Only for small intestinal cancer was a significantly elevated risk found among these patients hospitalized with Crohn's disease.

Adenocarcinoma↗