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Biomedical subjects

R Bergström

Publications and source records attributed to R Bergström.

At least 91 records · Page 5Linked to original sources
PubMed1996

Predictors of late mortality in cutaneous malignant melanoma--a population-based study in Sweden.

We determined risk factors for late deaths from cutaneous malignant melanoma (CMM) based on clinical characteristics at diagnosis, initial surgical treatment, histopathologic features of the primary tumor and type of eventual recurrences during follow-up. We examined deaths from CMM 8 or more completed years after the initial diagnosis in a case-control study nested in a nationwide cohort comprising all 8,838 patients with CMM diagnosed in Sweden during 1960-1978 with complete follow-up through 1986. There were 285 case patients and 285 control patients, individually matched by sex, age and follow-up time. Conditional logistic regression was used to obtain odds ratios (OR) as estimates of the relative risk. The risk of late mortality increased stepwise, almost 19-fold, with increasing tumor thickness from < or = 0.75 to > or = 7.00 mm. Besides the thickest tumors (> or = 7.00 mm), those of intermediate thickness (1.50-2.49 mm) had the highest risk (OR 8.5). After adjustment for tumor thickness, non-radical primary surgical treatment increased the risk of late mortality almost 3-fold while prophylactic lymph node dissection entailed a significantly reduced risk of late mortality (OR 0.5); the histopathologic features increasing level of invasion and vertical growth phase also remained significantly associated with a poor outcome. In a multivariate model, non-radical primary surgical treatment, prophylactic lymph node dissection, vertical growth phase, level of invasion and lymphocyte reaction were independent predictors of late mortality.

Adult↗
PubMed1996

Increase in testicular cancer incidence in six European countries: a birth cohort phenomenon.

BACKGROUND: For unknown reasons, the age-standardized incidence of testicular cancer has shown a rapid increase in virtually all countries (mostly Western) studied. For populations with a sufficiently long period of cancer registration, this development can be traced back to the first half of this century. PURPOSE: By evaluating data from six countries with long periods of cancer registration (Denmark, Norway, Sweden, the former German Democratic Republic [East Germany], Finland, and Poland), we sought to determine whether the increase in testicular cancer risk follows a birth cohort pattern and, if so, to quantify and compare any birth cohort effects. METHODS: A total of 30,908 incident cases of testicular cancer, diagnosed from 1945 through 1989 in men who were 20-84 years of age, were identified in population-based cancer registries in the six countries. In addition to performing simple trend analyses, we fitted several Poisson regression models (with the explanatory variables age, time period [calendar time], and birth cohort) to the data. Individual models were estimated by the maximum likelihood method. RESULTS: The age-standardized incidence of testicular cancer was found to vary among the six populations and, on the basis of total registration data, increased annually at rates ranging from 2.3% (in Sweden) to 5.2% (in East Germany). A comparison of several regression models indicated that birth cohort was a stronger determinant of testicular cancer risk than was calendar time for all six populations. Within each population, little variation in testicular cancer risk was observed for men born between 1880 and 1920; thereafter, the risk began to increase. Among men born in Denmark, Norway, and Sweden between 1930 and 1945 (the period encompassing the Second World War), the increasing trend in risk was interrupted (i.e., a leveling in risk occurred). After 1945, an uninterrupted increase in risk was observed for all six populations. With men born around 1905 as the reference group, the relative risk of testicular cancer for those born around 1965 varied from 3.9 (95% confidence interval [CI] = 2.7-5.6) in Sweden to 11.4 (95% CI = 8.3-15.5) in East Germany. CONCLUSIONS AND IMPLICATIONS: The increasing trend in testicular cancer risk observed for these six populations follows a birth cohort pattern. This distinct risk pattern provides a framework for the identification of specific etiologic factors.

Adult↗
PubMed1996

Marmor modular knee plateau positioning and prosthesis survival in 55 knees with rheumatoid arthritis.

In a long-term follow-up of 55 Marmor knee arthroplasties in patients with rheumatoid arthritis operated on between 1975 and 1977, the radiologically visible indicator wire was used to identify the position of the tibial components. The survival rate of the prostheses at 15 years was 0.71, and the revisions were evenly distributed over the observation period of 16 years. No significant relationship was found between the slope of the tibial components postoperatively and the survival of the prostheses. However, a postoperative valgus angle of the leg of 3 deg or more tended to increase the risk of revision (RH = 2.7, 95% CL = 0.8-8.9). The patient's sex, affected side or weight did not influence prosthesis survival.

Adult↗
PubMed1996

Screening for osteopenia and osteoporosis: selection by body composition.

There is a great need for simple means of identifying persons at low risk of developing osteoporosis, in order to exclude them from screening with bone mineral measurements, since this procedure is too expensive and time-consuming for general use in the unselected population. We have determined the relationships between body measure (weight, height, body mass index, lean tissue mass, fat mass, waist-to-hip ratio) and bone mineral density (BMD) in 175 women of ages 28-74 years in a cross-sectional study in a county in central Sweden. Dual-energy X-ray absorptiometry was performed at three sites: total body, L2-4 region of lumbar spine, and neck region of the proximal femur. Using multiple linear regression models, the relationship between the dependent variable, BMD, and each of the body measures was determined, with adjustment for confounding factors. Weight alone, in a multivariate model, explained 28%, 21% and 15% of the variance in BMD of total body, at the lumbar spine and at the femoral neck according to these models. The WHO definition of osteopenia was used to dichotomize BMD, which made it possible, in multivariate logistic regression models, to estimate the risk of osteopenia with different body measures categorized into tertiles. Weight of over 71 kg was associated with a very low risk of being osteopenic compared with women weighing less than 64 kg, with odds ratios (OR) of 0.01 (95% confidence interval (CI) 0.00-0.09), 0.06 (CI 0.02-0.22) and 0.13 (CI 0.04-0.42) for osteopenia of total body, lumbar spine and femoral neck, respectively. Furthermore a sensitivity/specificity analysis revealed that, in this population, a woman weighing over 70 kg is not likely to have osteoporosis. Test specifics of a weight under 70 kg for osteoporosis (BMD less than 2.5 SD compared with normal young women) of femoral neck among the postmenopausal women showed a sensitivity of 0.94, a specificity of 0.36, positive predictive value (PPV) of 0.21, and negative predictive value (NPV) of 0.97. Thus, exclusion of the 33% of women with the highest weight meant only that 3% of osteoporotic cases were missed. The corresponding figures for lumbar spine were sensitivity 0.89, specificity 0.38, PPV 0.33, and NPV 0.91. All women who were defined as being osteoporotic of total body weighed under 62 kg. When the intention was to identify those with osteopenia of total body among the postmenopausal women we attained a sensitivity of 0.92 and a NPV of 0.91 for a weight under 70 kg, whereas we found that weight could not be used as an exclusion criterion for osteopenia of femoral neck and lumbar spine. Our data thus indicate that weight could be used to exclude women from a screening program for postmenopausal osteoporosis.

Absorptiometry, Photon↗
PubMed1996

Factors influencing recurrence in Crohn's disease. An analysis of a consecutive series of 353 patients treated with primary surgery.

PURPOSE: This study was undertaken to investigate the factors that influenced the risk of symptomatic recurrence in patients with Crohn's disease who were treated with primary resective surgery. METHODS: Data regarding age, gender, time from diagnosis to surgery, medication, preoperative infectious complications, laboratory values, emergency/elective surgery, location and extent of disease, and resection margins were analyzed in relation to recurrence in 353 patients who were undergoing a "curative" resection in 1969 to 1986. RESULTS: Univariate analyses showed a higher risk of recurrence in women with ileal and ileocolonic disease than in men (P < 0.05), in patients with ileocolonic disease compared with those with isolated ileal disease (P < 0.05), and in ileal disease patients with an increased disease extent (P < 0.05). In a multivariate analysis performed on patients with ileal disease, increased disease extent, limited resection on the colonic side, and referral from other hospitals were three independent variables that indicated an increased risk of recurrence (P < 0.05). Length of disease-free resection margins did not influence the risk of recurrence either in univariate or in multivariate analysis (P > 0.05). CONCLUSIONS: Disease extent has prognostic value regarding the risk of symptomatic recurrence in Crohn's disease, whereas the length of resection margins does not influence the risk of relapse. These results favor a conservative approach, particularly in patients with extensive disease.

Adult↗
PubMed1996

Mutant p53 protein as a predictor of survival in endometrial carcinoma.

The expression of mutated p53 protein was studied in paraffin-embedded, formalin-fixed tumour specimens from 183 women with endometrial carcinoma. Fifty-five per cent of the specimens were negative, whereas the staining intensity was weak, moderate or strong in 15, 2 and 28% of cases, respectively. Strong p53 expression (> 75% of the cells stained) was more common in uterine papillary serous cancers and clear cell cancers than in other tumour subtypes (P < 0.001), as well as in poorly differentiated tumours (P < 0.01) and in tumours with nuclear grade 3 (P < 0.0001). Strong p53 expression was also more frequently found in aneuploid tumours (P < 0.0001) and in tumours with a high S-phase fraction (P < 0.001). Strong p53 expression was highly predictive of poor survival in the univariate analysis (P = 0.006) and in the Cox multivariate analysis which included age, stage and grade. However, it lost most of its impact when the strongly prognostic nuclear grade and ploidy were added to the multivariate models.

Adult↗
PubMed1996

Amputation risk and survival after embolectomy for acute arterial ischaemia. Time trends in a defined Swedish population.

OBJECTIVES: To assess the outcome of embolectomy over an 19 year period. METHODS: Time trends in the outcome of acute arterial thrombo-embolectomy of the extremities were analysed in a population-based cohort of 1190 patients operated on between 1965-83. RESULTS: A total of 262 (22%) initial amputations were performed. The limb salvage rates at 5 years postoperatively were lower between 1975-79 (61%) than between 1965-69 (81%). A proportional hazards model revealed a relative hazard (RH) of amputation of 2.2 (95% confidence interval (CI) 1.3-3.3) for 1975-79 compared with 1965-69. Operation at any district hospital entailed a 70% higher risk of amputation (RH 1.7; 95% CI 1.3-2.5) compared with the University hospital. The relative survival rate at 5 years postoperatively decreased towards the end of the study period (33% between 1975-79 compared with 43% between 1965-69). Younger age-groups had a considerably lower risk of death in the University hospital compared with the county and district hospitals. CONCLUSIONS: Contrary to the results in other hospital based reports no improvement in amputation or survival rates since 1965 could be demonstrated in this large series with no patient selection.

Acute Disease↗
PubMed1996

Long-term trends in incidence of and mortality from acute myocardial infarction and stroke in women: Analyses of total first events and of deaths in the Uppsala Health Care Region, Sweden.

We studied the trends from 1969 to the mid-1980s in the incidence and mortality of acute myocardial infarction and stroke in Swedish women residing in the Uppsala Health Care Region. We used data from the Inpatient Care and Causes of Death registers to obtain total first event incidence and mortality rates. In our population, there were 20,182 acute myocardial infarctions and 30,462 stroke events, and 17,359 and 21,336 deaths, respectively. We found an average overall annual increase of 1.3% in the age-standardized incidence of acute myocardial infarction during the 1970s, followed by decreasing rates during the early 1980s. Mortality was virtually unchanged. Notably, among women 45-49 years of age, we observed a rising trend during the whole period, whereas in the oldest age groups, the increase slowed and reversed in the latter years. Both the incidence and mortality for stroke declined steadily: the age-standardized incidence fell by an average of 2.1% per year for all stroke and 7.8% for intracerebral hemorrhage. The falling rate of stroke was best explained by birth cohort effects, with a 30% reduction in women born in 1920 and later as compared with those born in 1890. We conclude that important changes in Swedish women's cardiovascular health have taken place and that increasing cigarette smoking and hypertensive treatment are major determinants.

Adult↗
PubMed1996

Carcinoma of the endometrium: do the nuclear grade and DNA ploidy provide more prognostic information than do the FIGO and WHO classifications?

The aim of this study was to compare the World Health Organization (WHO), the International Federation of Gynecology (FIGO), and nuclear grading systems and to evaluate their reproducibility, as well as their prognostic impact, in relation to clinical variables and DNA ploidy. The study comprised 266 women with endometrial carcinoma in clinical stages I-IV. Low-risk patients, i.e., patients with grade 1-2 tumors in clinical stage I, were generally not included. In univariate Cox analyses, WHO, FIGO, and especially nuclear grading (p < 0.001), as well as age, stage, and ploidy, were prognostic regarding survival. In the multivariate Cox analyses, WHO and FIGO grades yielded little further independent information beyond nuclear grade. When DNA ploidy was added to the analyses, nuclear grade lost most of its impact because aneuploidy was a powerful factor (p < 0.001) that covaried with nuclear grade. The WHO, FIGO, and nuclear grading systems were found to be subjective, with correlation coefficients of approximately 0.60 between different pathologists. Age, stage, and aneuploidy were the most important predictors of outcome in the multivariate analyses. Nuclear grade was a strong prognostic factor in the univariate analyses and a more important indicator than the commonly used histopathological grading systems.

Adult↗
PubMed1996

Prognostic significance of the microvascular count in colorectal cancer.

PURPOSE: To investigate the potential correlations between a high microvascular count and the survival rate in colorectal cancer. MATERIALS AND METHODS: Three markers for endothelial cells--Ulex Europaeus Lectin (UEA), a polyclonal anti-von Willebrand factor (vWF) antibody, and a monoclonal anti-CD31 antibody (all from Dakopatts, Glostrup, Denmark)--were used for immunohistochemical detection of microvessels in whole-mount sections from 15 colorectal cancers. Areas with higher microvascular density were homogeneously distributed in the sections, regardless of the marker used. The anti-vWF antibody was subsequently used for quantification of microvessels in full-cross tumor biopsies collected from 212 consecutive surgical specimens. The correlations between the mean number of microvessels in areas with the highest microvascular density and tumor differentiation, tumor stage according to Dukes', and survival time were investigated. RESULTS: A significantly longer survival time was shown for patients who had tumors with a mean of more than 10 anti-vWF-positive microvessels, as compared with those who had < or = five. Tumors with a microvascular count between six and 10 microvessels behaved in-between. There was no correlation between the number of microvessels and tumor differentiation or Dukes' stage. CONCLUSION: The number of microvessels measurable in tumor biopsies seems to be a prognostic predictor independent of Dukes' stage in colorectal cancer. However, our results are opposite to the findings in other tumor types investigated so far; we found that a high microvascular count predicted a longer survival time, rather than a shorter one. Determination of the microvascular count can be of importance in therapy selection even before, or immediately after, surgery, ie, before Dukes' stage is known.

Adult↗
PubMed1996

Reproductive history and cigarette smoking as risk factors for thyroid cancer in women: a population-based case-control study.

A population-based case-control study was conducted in Northern Norway and Central Sweden to investigate hormonal and reproductive factors and cigarette smoking as determinants of papillary and follicular thyroid carcinoma in women. Information on 191 histologically confirmed cases and 341 age-matched controls was included. No clear association was found with regard to the number of live births, number of pregnancies, a history of incomplete pregnancies, or the use of oral contraceptives or hormonal replacement therapy. However, an early first childbirth (before 20 years of age, or less than 5 years after menarche) was associated with an increased risk of thyroid cancer. There was an increased risk of thyroid cancer among women with a history of artificial menopause compared to those with a spontaneous menopause [odds ratio (OR), 2.52; 95% confidence interval (CI), 0.96-6.62], which was more pronounced for the papillary carcinoma and after adjustment for age at menopause and use of replacement therapy. Cigarette smokers had a decreased risk of borderline statistical significance compared to nonsmokers (OR, 0.69; 95% CI, 0.47-1.01), particularly among premenopausal women (OR, 0.60; 95% CI, 0.38-0.96). This negative association persisted after adjustment for parity, hormonal treatments, and education. Women who started smoking before the age of 15 experienced a marked reduction in risk (OR, 0.38%; 95% CI, 0.18-0.80¿). Moreover, there was a suggestion of a dose-response effect with the amount of cigarettes smoked daily and with duration of the habit. Both the increased risk of artificial menopause and the negative association with smoking are compatible with a relation between levels of estrogens and thyroid cancer among women.

Adenocarcinoma, Follicular↗
PubMed1996

Malignant melanoma: reduced risk associated with early childbearing and multiparity.

Pigmentary changes during pregnancy and sex-specific differences in incidence patterns of cutaneous malignant melanoma (CMM) suggest that sex hormones may be involved in the development of CMM. We explored possible associations between childbearing and the risk of CMM in a case-control study "nested' in a nation-wide cohort. A total of 4,779 incident cases of CMM in women aged 24-65 were compared with 23,888 individually age-matched controls. Delayed childbearing was associated with an increased risk of CMM, corresponding to approximately 16% per 5 years. Parous women had a significantly lower risk of CMM compared with nulliparous women; in univariate analysis there was an 8% reduction in risk for each additional birth (odds ratio = 0.92; 95% confidence interval = 0.89-0.95). In multivariate analyses the risk of CMM was best explained by a model including both age at first birth and parity. Age at first birth was the most important variable. Time since most recent birth was unrelated to risk of CMM. These findings indicate that early childbearing and multiparity reduce the risk of CMM. Conceivable explanations are hormonal changes induced by childbearing, enhanced immunologic activity via exposure to fetal antigens during pregnancy, or long-lasting effects of pregnancy-associated hyperpigmentation. Our results need confirmation in studies with proper adjustment for confounding; less sun exposure in young mothers and high parity women may represent an alternative explanation but is unlikely to explain entirely the twofold difference in risk found between extreme categories of age at first birth and parity.

Adult↗
PubMed1996

Lifestyle factors and prostate cancer risk: a case-control study in Sweden.

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.

Adult↗
PubMed1995

Low efficiency of cytologic screening for cancer in situ of the cervix in older women.

Cytologic screening for cervical cancer has proven to be beneficial in many countries, although the value of this intervention in women older than 50 years remains controversial. The purpose of this study was to investigate the efficiency of detecting cancer in situ by means of a cytologic smear at different ages, with special emphasis on the benefit of screening in women above the age of 50. We analyzed 466,275 smears taken in an open cohort of 118,890 women in Sweden between 1969 and 1988. The number of cancers in situ detected per 1,000 smears, the detection ratio, was used as an outcome measure in univariate analyses and in multivariate regression models. Cancer in situ was detected in 1,076 women in the study cohort. The detection ratio peaked at ages 30 to 34 and decreased heavily during the next 15 years of age. The efficiency of taking smears at ages above 50 was only 20 per cent (OR, 0.19; 95% CI, 0.14-0.26) of that at ages 30 to 34. These results were not changed when adjusting for time period and time interval since the previous smear. In spite of a high incidence of invasive cervical cancer in older women, the benefit of cytologic screening to detect cancer in situ above the age of 50 is uncertain.

Adult↗
PubMed1995

International renal-cell cancer study. III. Role of weight, height, physical activity, and use of amphetamines.

Although numerous studies have identified obesity or high relative weight as a risk factor for renal-cell cancer in women, the degree to which this effect is present in men remains unclear. A multicenter population-based case-control study concerning incident cases of histologically verified renal-cell cancer (n = 1,732) and age- and sex-matched controls (n = 2,309) was conducted in Australia, Denmark, Germany (2 centers), Sweden and the United States. Relative weight was estimated by the body mass index, and the association between this factor and other factors, such as height, physical activity and use of amphetamines, was measured by the relative risk estimated in logistic regression models. Body mass index was found to be a risk factor among women and, to a lesser extent, among men. A 3-fold increased risk (RR = 3.6, 95% CI = 2.3-5.7) was observed for women with a relative weight in the top 5% compared with those in the lowest quartile. Rate of weight change (estimated as weight change per annum in kilograms) appeared to be an independent risk factor among women but not among men. Physical activity and height were unrelated to risk of renal-cell cancer regardless of level of BMI, while use of amphetamines was associated with an increased risk among men, although no dose or duration effect was seen. Our findings verify the link between high relative weight and risk of renal-cell cancer, particularly among women. The mechanism that underlies this association is, however, still unclear, although the rate of weight change may play a role.

Adult↗