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Per Hall

Publications and source records attributed to Per Hall.

52 records · Page 3Linked to original sources
PubMed2004

Incidence trends of adult primary intracerebral tumors in four Nordic countries.

Brain tumors are some of the most lethal adult cancers and there is a concern that the incidence is increasing. It has been suggested that the reported increased incidence can be explained by improvements in diagnostic procedures, although this has not been totally resolved. The aim of our study was to describe the incidence trends of adult primary intracerebral tumors in four Nordic countries during a period with introduction of new diagnostic procedures and increasing prevalence of mobile phone users. Information about benign and malignant primary intracerebral tumor cases 20-79 years of age was obtained from the national cancer registries in Denmark, Finland, Norway and Sweden for the years 1969-98 and estimates of person-years at risk were calculated from the information obtained from national population registries. Annual age standardized incidence rates per 100,000 person-years were calculated and time trends analyses were carried out using Poisson regression. The overall incidence of all intracerebral tumors ranged from 8.4-11.8 for men and 5.8-9.3 for women, corresponding to an average annual increase of 0.6% for men (95% confidence interval [CI] = 0.4, 0.7) and 0.9% for women (95% CI = 0.7, 1.0). The increase in the incidence was confined to the late 1970s and early 1980s and coinciding with introduction of improved diagnostic methods. This increase was largely confined to the oldest age group. After 1983 and during the period with increasing prevalence of mobile phone users, the incidence has remained relatively stable for both men and women.

Adult↗
PubMed2004

Effect of low doses of ionising radiation in infancy on cognitive function in adulthood: Swedish population based cohort study.

OBJECTIVE: To determine whether exposure to low doses of ionising radiation in infancy affects cognitive function in adulthood. DESIGN: Population based cohort study. SETTING: Sweden. PARTICIPANTS: 3094 men who had received radiation for cutaneous haemangioma before age 18 months during 1930-59. MAIN OUTCOME MEASURES: Radiation dose to frontal and posterior parts of the brain, and association between dose and intellectual capacity at age 18 or 19 years based on cognitive tests (learning ability, logical reasoning, spatial recognition) and high school attendance. RESULTS: The proportion of boys who attended high school decreased with increasing doses of radiation to both the frontal and the posterior parts of the brain from about 32% among those not exposed to around 17% in those who received > 250 mGy. For the frontal dose, the multivariate odds ratio was 0.47 (95% confidence interval 0.26 to 0.85, P for trend 0.0003) and for the posterior dose it was 0.59 (0.23 to 1.47, 0.0005). A negative dose-response relation was also evident for the three cognitive tests for learning ability and logical reasoning but not for the test of spatial recognition. CONCLUSIONS: Low doses of ionising radiation to the brain in infancy influence cognitive abilities in adulthood.

Adolescent↗
PubMed2004

Mobile phone use and the risk of acoustic neuroma.

BACKGROUND: Radiofrequency exposure from mobile phones is concentrated to the tissue closest to the handset, which includes the auditory nerve. If this type of exposure increases tumor risk, acoustic neuroma would be a potential concern. METHODS: In this population-based case-control study we identified all cases age 20 to 69 years diagnosed with acoustic neuroma during 1999 to 2002 in certain parts of Sweden. Controls were randomly selected from the study base, stratified on age, sex, and residential area. Detailed information about mobile phone use and other environmental exposures was collected from 148 (93%) cases and 604 (72%) controls. RESULTS: The overall odds ratio for acoustic neuroma associated with regular mobile phone use was 1.0 (95% confidence interval = 0.6-1.5). Ten years after the start of mobile phone use the estimates relative risk increased to 1.9 (0.9-4.1); when restricting to tumors on the same side of the head as the phone was normally used, the relative risk was 3.9 (1.6-9.5). CONCLUSIONS: Our findings do not indicate an increased risk of acoustic neuroma related to short-term mobile phone use after a short latency period. However, our data suggest an increased risk of acoustic neuroma associated with mobile phone use of at least 10 years' duration.

Acoustic Stimulation↗
PubMed2003

Thyroid cancer risk after thyroid examination with 131I: a population-based cohort study in Sweden.

Ionizing radiation is the only established cause of thyroid cancer, though the effect of diagnostic administration of (131)I on thyroid cancer risk appears minimal. The annual number of thyroid examinations using radioiodine is currently 5 per 1,000 individuals worldwide, so this issue is of public health importance. Our objective was to evaluate the excess risk of thyroid cancer following a range of known doses of (131)I administered for diagnostic purposes. We conducted a nationwide, population-based cohort study in Sweden including all 36,792 individuals who received (131)I for diagnostic purposes during 1952-1969 and were alive and free of thyroid cancer 2 years after exposure. Accrual of person-time at risk commenced 2 years after the first (131)I administration. Follow-up for cancer was to the end of 1998. Standardized incidence ratios (SIRs) were calculated as the ratio between the observed and expected numbers of thyroid cancers. Estimates were stratified by previous exposure to external radiation therapy to the neck, reason for thyroid examination, (131)I dose, sex, age at exposure and time since exposure. Thyroid cancers (n = 129) were diagnosed during 886,618 person-years at risk. Excess thyroid cancers were observed only among the 1,767 patients who reported previous external radiation therapy to the neck [SIR = 9.8, 95% confidence interval (CI) 6.3-14.6] and among those originally referred due to suspicion of a thyroid tumor (SIR = 3.5, 95% CI 2.7-4.4 for 11,015 patients without previous external radiation therapy). The 24,010 patients without previous exposure to external radiation therapy to the neck who were referred for a reason other than suspicion of a thyroid tumor received an estimated dose to the thyroid of 0.94 Gy. Among these patients, 36 thyroid cancers were observed compared to 39.5 expected (SIR = 0.91, 95% CI 0.64-1.26). We found no evidence that administration of (131)I for diagnostic purposes increases risk of thyroid cancer. However, our study included few patients under age 20, so the results apply primarily to exposure among adults. Our data suggest that protraction of dose may result in a lower risk than brief X-ray exposure of the same total dose.

Adolescent↗
PubMed2003

Incidence and survival of Swedish patients with differentiated thyroid cancer.

Papillary (PTC) and follicular (FTC) thyroid cancers are rare disorders but are, nevertheless, among the most common cancers in individuals below 40 years of age. From the population-based Swedish Cancer Registry we identified 3,588 individuals with PTC and 1,966 with FTC during 1958-87. Histopathology was determined by examining the original histopathology reports. The relative survival ratio (RSR) was used as the measure of patient survival. Incidence of both PTC and FTC was higher among women, especially for PTC and particularly during the fertile part of female life. Incidence of PTC increased significantly over time, a trend that was not observed for FTC. Five-year relative survival appeared to be higher for patients diagnosed with PTC compared to FTC, although this difference was almost completely explained by the confounding effect of age. Patients with PTC experience lower mortality during the period 7-20 years after diagnosis. Excess mortality was lower among women, although the magnitude of the difference varied with age and histopathology. In contrast to our perceptions based on clinical practice, we observed no difference in excess mortality between patients diagnosed with PTC and FTC during the years immediately after diagnosis (where the majority of deaths occur). Our data suggest that there may exist a subgroup of thyroid tumors with superior prognosis diagnosed in women during the fertile part of female life. Sex hormones may play a role in the etiology of these tumors.

Adenocarcinoma, Follicular↗
PubMed2003

From colour to tissue histology: Physics-based interpretation of images of pigmented skin lesions.

Through an understanding of the image formation process, diagnostically important facts about the internal structure and composition of pigmented skin lesions can be derived from their colour images. A physics-based model of tissue colouration provides a cross-reference between image colours and the underlying histological parameters. It is constructed by computing the spectral composition of light remitted from the skin given parameters specifying its structure and optical properties. The model is representative of all the normal human skin colours, irrespective of racial origin, age or gender. Abnormal skin colours do not conform to this model and thus can be detected. Once the model is constructed, for each pixel in a colour image its histological parameters are computed from the model. Represented as images, these 'parametric maps' show the concentration of dermal and epidermal melanin, blood and collagen thickness across the imaged skin as well as locations where abnormal colouration exists. In a clinical study the parametric maps were used by a clinician to detect the presence of malignant melanoma in a set of 348 pigmented lesions imaged using a commercial device, the SIAscope. Logistic regression identified the presence of melanin in the dermis, the abnormal distribution of blood within the lesion and the lesion size as the most diagnostically informative features. Classification based on these features showed 80.1% sensitivity and 82.7% specificity in melanoma detection.

Colorimetry↗
PubMed2003

Site-specific cancer incidence and mortality after cerebral angiography with radioactive thorotrast.

Few opportunities exist to evaluate the carcinogenic effects of long-term internal exposure to alpha-particle-emitting radionuclides. Patients injected with Thorotrast (thorium-232) during radiographic procedures, beginning in the 1930s, provide one such valuable opportunity. We evaluated site-specific cancer incidence and mortality among an international cohort of 3,042 patients injected during cerebral angiography with either Thorotrast (n = 1,650) or a nonradioactive agent (n = 1,392) and who survived 2 or more years. Standardized incidence ratios (SIR) for Thorotrast and comparison patients (Denmark and Sweden) were estimated and relative risks (RR), adjusted for population, age and sex, were generated with multivariate statistical modeling. For U.S. patients, comparable procedures were used to estimate standardized mortality ratios (SMR) and RR, representing the first evaluation of long-term, site-specific cancer mortality in this group. Compared with nonexposed patients, significantly increased risks in Thorotrast patients were observed for all incident cancers combined (RR = 3.4, 95% CI 2.9-4.1, n = 480, Denmark and Sweden) and for cancer mortality (RR = 4.0, 95% CI 2.5-6.7, n = 114, U.S.). Approximately 335 incident cancers were above expectation, with large excesses seen for cancers of the liver, bile ducts and gallbladder (55% or 185 excess cancers) and leukemias other than CLL (8% or 26 excess cancers). The RR of all incident cancers increased with time since angiography (P < 0.001) and was threefold at 40 or more years; significant excesses (SIR = 4.0) persisted for 50 years. Increasing cumulative dose of radiation was associated with an increasing risk of all incident cancers taken together and with cancers of the liver, gallbladder, and peritoneum and other digestive sites; similar findings were observed for U.S. cancer mortality. A marginally significant dose response was observed for the incidence of pancreas cancer (P = 0.05) but not for lung cancer. Our study confirms the relationship between Thorotrast and increased cancer incidence at sites of Thorotrast deposition and suggests a possible association with pancreas cancer. After injection with >20 ml Thorotrast, the cumulative excess risk of cancer incidence remained elevated for up to 50 years and approached 97%. Caution is needed in interpreting the excess risks observed for site-specific cancers, however, because of the potential bias associated with the selection of cohort participants, noncomparability with respect to the internal or external comparison groups, and confounding by indication. Nonetheless, the substantial risks associated with liver cancer and leukemia indicate that unique and prolonged exposure to alpha-particle-emitting Thorotrast increased carcinogenic risks.

Adult↗
PubMed2002

Risk of ovarian cancer in breast-cancer patients with a family history of breast or ovarian cancer: a population-based cohort study.

BACKGROUND: Patients with breast cancer who have mutations in the high penetrance genes BRCA1 and BRCA2, have an increased risk of ovarian cancer. Because these mutations are rare, easily obtained information such as age and family history of breast or ovarian cancer might be preferable for assessment of ovarian cancer risk in clinical practice. METHODS: We linked data from the Swedish Cancer Register to the Swedish Generation Register and generated a cohort of 30552 breast-cancer patients born after 1931, with information on breast and ovarian cancer diagnosis from 146117 first-degree relatives. Standardised incidence ratios (SIRs) with 95% CIs were calculated with nationwide rates of ovarian cancer, adjusted for age and calendar year. FINDINGS: During a mean follow-up of 6 years, 122 incident ovarian cancers were identified in the cohort, yielding an overall SIR of 2.0 (95% CI 1.6-2.4). The risk was higher in breast-cancer patients diagnosed before the age of 40 years, with a family history of breast cancer (5.6; 1.8-13.1) or ovarian cancer (17.0; 3.5-50.0). A consistently increased risk was noted in patients with a relative who was diagnosed before the age of 50 years, with either breast or ovarian cancer. Women with a family history of ovarian cancer have an almost 10% risk of developing ovarian cancer before the age of 70. INTERPRETATION: In young women with breast cancer, the risk of ovarian cancer is greatly raised when a family history of breast or ovarian cancer is present. Close medical surveillance, and perhaps even prophylactic oophorectomy, might be justified in high-risk groups.

Adult↗
PubMed2002

Risk of childhood leukaemia in the vicinity of nuclear installations--findings and recent controversies.

The identification of a local excess of cancer cases, possibly associated with ionizing radiation, always receives substantial media coverage and communication about clusters is difficult. We reviewed studies that examined the risk of leukaemia among young people near nuclear installations. An excess of leukaemia exists near some nuclear installations, at least for the reprocessing plants at Sellafield and Dounreay and the nuclear power plant Krümmel. Nonetheless, the results of multi-site studies invalidate the hypothesis of an increased risk of leukaemia related to nuclear discharge. Up until now, analytic studies have not found an explanation for the leukaemia clusters observed near certain nuclear installations. The hypothesis of an infectious aetiology associated with population mixing has been proposed, but needs to be investigated further. The review illustrates two recent examples in France (La Hague reprocessing plant) and in Germany (Krümmel power plant), where controversies developed after reports of increased leukaemia risks. These examples show the importance of recalling the current epidemiological knowledge and of using systematic recording of cases to replace the alleged excesses in a more general framework. Some elements should also be suggested from the recent French and German experiences to reinforce credibility in the results.

Adolescent↗
PubMed2002

Cancer incidence among Swedish patients exposed to radioactive thorotrast: a forty-year follow-up survey.

Thorotrast is an alpha-particle-emitting radiological contrast medium that caused chronic exposure to internal alpha-particle radiation when it was administered systemically. Cancer incidence in 432 Swedish patients exposed to Thorotrast was evaluated by computerized linkage of the cohort with the Swedish Cancer Register. Standardized incidence ratios (SIRs) were calculated as the ratio of observed cases in the cohort to expected cases in the general population. A total of 170 cancers occurring in 152 individuals were reported, whereas only 57 cases were expected. The SIR was significantly increased for cancer at all sites (3.0), with the largest excesses noted for primary liver and gallbladder cancer (SIR = 39.2). Other significantly elevated risks were observed for liver cancer not specified as primary, small intestine cancer, stomach cancer, leukemia, kidney cancer, CNS tumors, and pancreatic cancer. Among women, there was a significantly increased risk for lung cancer, based on a small number. Our results show that cumulative radiation exposure is directly related to carcinogenesis in the liver and gallbladder, which is consistent with earlier findings. In addition, there may be a relationship between radiation exposure and the development of other solid tumors.

Adolescent↗
PubMed2002

p53 mutations in leukemia and myelodysplastic syndrome after ovarian cancer.

PURPOSE: Although p53 mutations occur in alkylating agent-related leukemias, their frequency and spectrum in leukemias after ovarian cancer have not been addressed. The purpose of this study was to examine p53 mutations in leukemias after ovarian cancer, for which treatment with platinum analogues was widely used. EXPERIMENTAL DESIGN: Adequate leukemic or dysplastic cells were available in 17 of 82 cases of leukemia or myelodysplastic syndrome that occurred in a multicenter, population-based cohort of 23,170 women with ovarian cancer. Eleven of the 17 received platinum compounds and other alkylating agents with or without DNA topoisomerase II inhibitors and/or radiation. Six received other alkylating agents, in one case, with radiation. Genomic DNA was extracted and p53 exons 5, 6, 7, and 8 were amplified by PCR. Mutations and loss of heterozygosity were analyzed on the WAVE instrument (Transgenomic) followed by selected analysis by sequencing. RESULTS: Eleven p53 mutations involving all four exons studied and one polymorphism were identified. Genomic DNA analyses were consistent with loss of heterozygosity for four of the mutations. The 11 mutations occurred in 9 cases, such that 6 of 11 leukemias after platinum-based regimens (55%) and 3 of 6 leukemias after other treatments (50%) contained p53 mutations. Two leukemias that occurred after treatment with platinum analogues contained two mutations. Among eight mutations in leukemias after treatment with platinum analogues, there were four G-to-A transitions and one G-to-C transversion. CONCLUSIONS: p53 mutations are common in leukemia and myelodysplastic syndrome after multiagent therapy for ovarian cancer. The propensity for G-to-A transitions may reflect specific DNA damage in leukemias after treatment with platinum analogues.

Adult↗