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R Bergström

Publications and source records attributed to R Bergström.

At least 127 records · Page 7Linked to original sources
PubMed1994

Prognostic predictors in colorectal cancer.

PURPOSE: Better prognostic predictors in colorectal cancer than the Dukes stage are necessary for individualized therapy and follow-up. METHODS: Survival among 212 patients operated on for colorectal cancer was examined regarding various clinical, histopathologic, cellular, and serologic tumor characteristics. RESULTS: Beside the Dukes stage, which was the most powerful variable, the erythrocyte sedimentation rate, leukocyte blood count, alkaline phosphatase, aspartate aminotransferase, six different serum tumor markers, number of small blood vessels, and age were found to be significantly associated with survival. The leukocyte blood count, alkaline phosphatase, and aspartate aminotransferase retained their significance in a multivariate model including tumor differentiation, local tumor stage, and age. Inclusion of tissue polypeptide antigen, the most powerful tumor marker in the multivariate model, showed that only the tumor stage, tissue polypeptide antigen, and age were statistically significantly correlated to survival. This was valid both for the group of patients considered as potentially curable and for those who potentially have been cured (Dukes Stages A-C). CONCLUSIONS: A great number of prognostic predictors failed to discard Dukes stage as the best one. One serum tumor marker, tissue polypeptide antigen, contains independent additional prognostic information.

Adult↗
PubMed1994

Methodological aspects on measurements of temporal trends in melanoma survival.

We compared measurements of temporal trends in cancer survival either based on observed survival or relative survival. Survival rates for cutaneous malignant melanoma diagnosed in Sweden 1960-1982 were used as an example. In a proportional hazards model based on observed survival, the hazard ratio for patients diagnosed during the period 1975-1979 was 0.56 (95% confidence limits 0.49-0.64) in men and 0.45 (0.38-0.53) in women when the period 1960-1964 was the reference. When relative survival was the outcome measure, during the same period, the hazard ratio decreased to 0.47 (0.39-0.56) in men and 0.36 (0.29-0.44) in women. Thus, the effect of period of diagnosis was larger when the analysis was based on relative survival rates. The reasons for the differences between these two alternative measurements are explained in the article and advantages/disadvantages of the two approaches are discussed.

Adult↗
PubMed1994

Oral contraceptives and prognosis in breast cancer: effects of duration, latency, recency, age at first use and relation to parity and body mass index in young women with breast cancer.

The aim of this study was to examine associations between oral contraceptive (OC) use, body mass index (BMI = weight/height2) and prognosis in invasive breast cancer diagnosed before the age of 45. Survival analyses of a consecutive sample of breast cancer patients were undertaken. The cases were initially registered in a nationwide case-control study of OC use and risk of premenopausal breast cancer in Sweden and Norway. All 422 cases were under 45 years of age at diagnosis, and recruited from the reports to cancer registries (Sweden) or from surgical departments (Norway) during May 1984 through May 1985. Detailed information about OC exposure was obtained in the initial face-to-face interview. With Cox's proportional hazards analyses, a significantly lower hazard rate [relative hazard (RH) = 0.54; 0.31-0.94] was seen in short-term users (< 4 years)--but not in long-term (> or = 4 years) users--than in never-users of OC. Non-significant estimates for RHs lower than 1.0, i.e. better prognosis, with long recency (> 5 years) and latency (> or = 10 years) of OC use were noted. Prognosis was not influenced by age at first OC use or of its timing in relation to the first pregnancy. A higher BMI was associated with a poorer prognosis, RH 5.9 (2.0-17.8) for BMI > or = 29 versus BMI < 19, but BMI was not a confounder or an effect modifier of the association between OC use and prognosis. This study does not indicate that OC use prior to the diagnosis of breast cancer has any adverse effect on the prognosis, at least not in women under 45 years of age at diagnosis.

Adult↗
PubMed1994

Appraisal of a model for prediction of prognosis in advanced colorectal cancer.

Previously identified prognostic factors in advanced colorectal cancer were tested in an independent population for their relationship to survival by univariate and multivariate analyses. The new population comprised 198 patients included in a randomised chemotherapy trial. The earlier identified prognostic variables were: (1) haemoglobin level (B-Hb), (2) disease-free interval, (3) Karnofsky performance status (KPS), (4) number of symptoms, and (5) whether the primary tumour was removed or not. In the new population, variables (1-3) had significant relationships to survival in both univariate and multivariate analyses, whereas variable (4) was significant only in the univariate analysis. Variable (5) was not significantly related to survival in any analysis. When a group of additional variables (white blood cell count, B-thrombocytes, S-creatinine and liver function tests) was included, S-aspartate aminotransferase (S-ASAT) was a strong predictor of survival. The independent predictive value of B-Hb, disease-free interval and KPS was confirmed in this study. S-ASAT might be an additional important prognostic factor in advanced colorectal cancer. However, the results of this study indicate that any new prognostic factor should be viewed as preliminary until verified in an independent population.

Adult↗
PubMed1994

Surgical treatment of left ventricular aneurysm--assessment of risk factors for early and late mortality.

Consecutive patients operated on for left ventricular aneurysm from 1970 through August 1989 (n = 303) were evaluated with respect to survival. Early mortality, i.e. within 30 days, was 8.9%; 23% in patients who underwent aneurysm resection alone, 8.1% in cases of aneurysm resection with coronary artery bypass grafting (CABG), and 6.3% in those undergoing CABG only. Multivariate logistic regression revealed that advanced New York Heart Association (NYHA) functional class, non-use of the internal mammary artery as a graft and thromboendarterectomy increased the early risk. The total observed survival was 86% at 1 year, 72% at 5 years and 45% at 10 years. Multivariate analysis based on observed survival, using the Cox proportional hazards model, identified advanced NYHA functional class and non-use of the internal mammary artery as independent indicators of poor survival. Relative mortality, defined as the ratio of observed mortality in the study group to mortality among comparable persons from the general Swedish population, was used as a measure of disease-specific mortality. An apparent excess mortality in patients operated on for left ventricular aneurysm was found. A notable finding was that the use of the internal mammary artery to graft the left anterior descending artery improved the outcome substantially in patients with a left ventricular aneurysm.

Adult↗
PubMed1994

The relationship between an objective response to chemotherapy and survival in advanced colorectal cancer.

This analysis was conducted to evaluate the independent relationship between survival and response to chemotherapy in advanced colorectal cancer. In order to correct for the guarantee time effect, patients dying before the response evaluation were excluded from the analyses. A previously constructed prognostic model containing 11 variables was applied to 324 patients. When the response categories were analysed together with the prognostic variables, it was found that a response was associated with a definite survival advantage (P < 0.001), whereas the influence of all the other variables decreased. The corrected survival advantage (relative progressive disease) was 11 months after a complete response, 6 months after a partial response and 4 months after stable disease. The survival advantage was of a similar magnitude when the analyses were repeated in an independent population comprising 198 patients in whom the prognostic model was extended to include also a set of laboratory values. The results show that a response to chemotherapy is associated with a longer survival also after correction for the guarantee time effect and the distribution of prognostic variables.

Adult↗
PubMed1994

Trends in tumour characteristics and survival of malignant melanoma 1960-84: a population-based study in Sweden.

In Sweden, improvement in survival rates of patients with cutaneous malignant melanoma has counteracted the increase in incidence to produce a moderate rise in mortality. Our aim was to determine the possible impact of drift in diagnostic criteria, earlier diagnosis and changing biological features of the tumours upon trends in survival. We studied a stratified sample of 528 patients diagnosed between 1960 and 1984 in a strictly defined geographical region. No evidence of drift in diagnostic criteria was found. The proportion of patients with invasion level Clark II increased from 3.2% in 1960-64 to 22.5% in 1980-84, the proportion of thin melanomas (< or = 0.75 mm) increased from 9.4% to 31.5% and the tumour thickness decreased significantly between each 5 year period of diagnosis. These changes are most likely the results of earlier diagnosis. However, changes in tumour characteristics have occurred, since the proportion of superficially spreading malignant melanoma increased from 35% in 1960-64 to 51% in 1980-84 and the proportion of acral lentiginous melanoma decreased from 11% to 2%. The proportion of nodular melanomas remained fairly constant. The proportion of tumours with lymphocytic reaction did not change, whereas those with histological regression increased slightly. Proportional hazards analyses showed a significantly lower survival in patients diagnosed in 1960-64 but no apparent trend after 1965. This finding remained after adjustment for all studied clinical and histopathological factors which point towards changes in unmeasured biological features of the disease.

Cohort Studies↗
PubMed1994

Defining a high mortality risk group among women with primary breast cancer.

Increasing interest has been focused on DNA ploidy, hormone receptor status and tumour size as prognostic factors in node-negative breast cancer. We analysed these factors in patients operated on for primary invasive breast cancer between January 1981 and December 1987 in a prospective study of 248 women with no involved axillary nodes and 188 women with positive nodes followed until 15 April 1989. Oestrogen or progesterone receptor negativity, aneuploidy and tumour diameter exceeding 20 mm were studied as negative prognostic signs in life table analyses and Cox proportional hazards models of corrected survival. Corrected survival decreased with increasing number of negative signs. Three to four signs yielded a statistically significant, two- to threefold higher risk than the others. Survival estimates by life table analyses differed by 20% at 5 years. In the whole group, women with three or four negative factors had a relative risk of dying from their disease more than twice that of the others. Women with no involved nodes and with three or four negative factors had a risk of dying from breast cancer similar to that of node-positive women with fewer than three.

Aneuploidy↗
PubMed1994

Self-administered food frequency questionnaire: the effect of different designs on food and nutrient intake estimates.

BACKGROUND: Our objective was to determine the possible influence that different designs of a food frequency questionnaire might have on food, energy and nutrient intake estimates. METHODS: A population-based survey included 6783 women, 40-70 years old, living in central Sweden. Using a factorial study design, we compared eight different types of questionnaire covering combinations of three factors: increasing/decreasing frequency categories; addition of portion sizes; and addition of non-dietary questions. All questionnaires included the same list of 60 food items. One of the eight questionnaires was mailed to each subject according to a random assignment. The overall response rate was 77%. RESULTS: Compared with increasing frequencies, decreasing order of frequency categories entailed 3-11% higher estimates of mean intake for 7 of 14 food groups, 4% higher estimates for energy and 3-6% higher estimates for 13 of 18 nutrients. Addition of portion sizes had heterogeneous effects, both on dietary items (e.g. from -30% decrease for eggs to +76% increase for coffee) and on calculated nutrients (from -7% for beta-carotene to +19% for vitamin C). The inclusion of some additional non-dietary questions did not influence the estimated mean intake of any food or nutrient. CONCLUSIONS: The results of this study have implications for the design of questionnaires and for pooled analyses in nutritional epidemiology, when different food questionnaires are used.

Adult↗
PubMed1994

Survival after coronary artery bypass grafting. Experience from 4661 patients.

The duration of the reduction of mortality after coronary artery bypass grafting (CABG) is an important issue and this study was undertaken to evaluate time in relation to excess mortality among CABG patients compared with the general population. Survival was analysed in 4661 patients who had undergone their first isolated CABG. Observed survival was related to that expected among subjects from the general Swedish population stratified by age, sex and 5-year calendar period, to calculate relative survival and estimate disease-specific survival. Relative survival (including all deaths) was 94.6% at 5 years, 82.5% at 10 years, and 59.9% at 15 years. A multivariate model based on relative survival rates adjusted for age, year of surgery, severity of coronary disease, left ventricular function, and smoking habits was used. Compared with the first year of follow-up, the relative hazard (a measure of the risk of death) was at a minimum 2 years after surgery, but was dramatically increased after about 8 years. Relative survival was worsened by smoking at the time of operation and by moderate or severe left ventricular dysfunction pre-operatively. The survival rate was higher among patients operated on after 1985 than among those operated on earlier.

Adult↗
PubMed1994

Extent of blood transfusion and cancer-related mortality after cystectomy and urinary diversion for bladder cancer.

OBJECTIVE: To assess the possible adverse effect of peri-operative blood transfusion on cancer-related survival after radical cystectomy for bladder cancer. PATIENTS AND METHODS: The hospital records of 130 patients treated with cystectomy and urinary diversion for bladder cancer between 1967 and 1986 were retrospectively reviewed. RESULTS: Standard proportional hazards estimation revealed tumour stage and radiation response after pre-operative irradiation to be significantly associated with cancer-related mortality, whereas age, tumour grade or the extent of peri-operative blood transfusion were not. In models which allowed time varying effects a significantly changed effect of blood transfusion (> or = 7 versus < or = 6 units) was observed, from an initially insignificantly increased relative hazard (RH) (RH = 1.44 at 6 months) to an insignificantly decreased effect after longer follow-up (RH = 0.53 after 2 years). CONCLUSION: Although no overall association between blood transfusion and cancer-related mortality was found, a tendency towards an increased risk early in the follow-up period was observed if more than 6 units were transfused. However, these results need confirmation in further studies before a restrictive attitude towards peri-operative blood transfusion is recommended.

Adult↗
PubMed1994

The role of obesity and weight fluctuations in the etiology of renal cell cancer: a population-based case-control study.

The causes of renal cell cancer (RCC) are poorly understood. Besides smoking, obesity remains the only risk factor that is fairly well established. The association between obesity and RCC appears stronger and more consistent in women than in men. We investigated the question of whether this apparent sex difference could be explained by repeated weight changes (weight cycling), less physical exercise, or pharmacological treatment of obesity in women. Structured face-to-face interviews were carried out with 379 (70% of all eligible) incident cases of RCC and 353 (72% of eligible) controls. The relationships between RCC and adult height, weight, and body mass index (BMI), defined as weight/height, were analyzed. Odds ratios (ORs) were estimated through logistic regression. No association was found between adult height and RCC. In men, weight and BMI appeared at most to be weakly related to risk of RCC. In women, higher adult weight and BMI (usual, highest, and lowest) and also high BMI at ages 30, 40, and 50 years were consistently associated with a significantly increased risk of RCC. Women with an usual adult BMI in the top 5% had a nearly 3-fold increased risk of RCC [OR, 2.67; 95% confidence interval (CI), 1.02-7.01]. Compared with individuals with no weight-loss periods, 2 or more such periods implied an OR of 0.96 (95% CI, 0.32-2.90) in men and 3.87 (95% CI, 1.20-12.45) in women. Physical activity at work reduced the risk of RCC in men but not women. Regular use of diet pills containing amphetamine was associated with an increased risk of RCC (OR, 4.06; 95% CI, 1.35-12.22).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Diet and risk of gastric cancer. A population-based case-control study in Sweden.

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

Adult↗
PubMed1993

Detection of preinvasive cancer of the cervix and the subsequent reduction in invasive cancer.

BACKGROUND: Cytologic screening and follow-up can reduce the incidence of cervical cancer by detection and removal of precursor lesions. It is unknown, however, whether differences in histopathologic criteria for these precursor lesions affect the benefit of screening. These criteria may be difficult to study, but they are likely to be reflected in reported incidence of in situ cancer in small areas of Sweden. PURPOSE: Our purpose was to test the hypothesis that the benefit of screening can be predicted by histopathologic criteria as reflected in the reported incidence of cancer in situ. METHODS: Incidence data were from the Swedish National Cancer Registry. Regression models showing the relationship between in situ and invasive cancer were formulated and estimated. Each county (total, 24) was a unit of measurement, and adjustment was made for the incidence of invasive cancer before screening. RESULTS: During population-based screening in Sweden, the incidence of cancer in situ varied about fourfold among the 24 counties, which indicates that the criteria used to diagnose cancer in situ differed markedly. No statistically significant (P < .05) associations were found between the incidence of cancer in situ in 1965, 1970, or 1975 and the reduction in invasive cancer 5, 10, or 15 years later. According to the best-fitting model, detection of 100 extra cases of cancer in situ per 100,000 women per year in 1975 resulted in a reduction of 1.0 (95% confidence interval [CI] = -1.6-3.7) cases of invasive cancer 10 years later. The corresponding best model estimate implied a reduction of 4.6 cases (95% CI = 1.5-7.7) in a model restricted to cancer in situ in patients aged 20-50 years (when organized screening took place), invasive cancer in patients aged 30-60 years, and cancer in situ measured in 1970. CONCLUSIONS: The absent, or at most weak, association between detection of cancer in situ and subsequent reduction in invasive cancer indicates that relaxed histopathologic criteria for cancer in situ may result in extensive, unnecessary treatment of lesions that would regress spontaneously. IMPLICATION: Further studies are urgently needed to enable identification of neoplasms likely to progress to invasive, fatal disease.

Adult↗
PubMed1993

Hormone replacement therapy and the risk of stroke. Follow-up of a population-based cohort in Sweden.

BACKGROUND: The protective effect of postmenopausal estrogen replacement therapy on coronary heart disease has been shown in several studies. However, the effect on stroke is more controversial, and data on estrogen-progestin combinations are sparse. METHODS: A total of 23,088 women living in the Uppsala (Sweden) Health Care Region were identified from pharmacy records as having been prescribed noncontraceptive estrogens during 1977 through 1980. They were followed up from 1977 to 1983 for admissions to the hospital because of a first stroke (International Classification of Diseases, Eighth Revision, codes 430 through 438 and 344). The mean observation time was 5.8 years. The expected number was based on person-years in the cohort and incidence rates in the population of the region. RESULTS: Overall, 361 cases of first stroke were observed in the cohort, as compared with 403.2 expected (relative risk [RR], 0.90; 95% confidence limits, 0.81, 0.99). The RR for acute stroke (International Classification of Diseases, Eighth Revision, codes 431 through 436) was 0.85 (0.75, 0.97). In women younger than 60 years at entry who were prescribed estradiol compounds (1 to 2 mg) or conjugated equine estrogens (0.625 to 1.25 mg), the risk of any stroke was reduced by almost 30% (RR, 0.72; 0.58, 0.88) and the risk of acute stroke was reduced by 40% (RR, 0.61; 0.46, 0.79). Women prescribed a combined estradiol-levonorgestrel brand also had a lowered risk of stroke (RR, 0.61; 0.40, 0.88). Weak compounds (mainly estriol) showed no stroke-protective effect, nor was there any relationship between hormone replacement and risk of subarachnoid hemorrhage. CONCLUSION: Hormone replacement therapy with potent estrogens alone or cyclically combined with progestins can, particularly when started shortly after menopause, reduce the risk of stroke.

Cerebrovascular Disorders↗
PubMed1993

Increasing cancer risk in younger birth cohorts in Sweden.

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

Adult↗
PubMed1993

Fracture of the distal forearm as a forecaster of subsequent hip fracture: a population-based cohort study with 24 years of follow-up.

OBJECTIVE: To determine the long-term risk of hip fracture following fracture of the distal forearm. DESIGN: Registry-based cohort study comparing patients with a fracture of the distal forearm with a population-based cohort. FRACTURE COHORT: All women and men above 40 years of age with a radiologically verified fracture of the distal forearm during a 5-year period, 1968-1972, in all 1,126 women and 212 men. CONTROL COHORT: An equal number of population-based, age- and sex-matched control persons selected from a population register. MEASUREMENTS: All cohort members were followed up individually through record linkage until the first hip fracture, emigration, death, or the end of 1991. The cohort members contributed a total of 40,832 person-years of observation, and altogether 365 cases of hip fractures were observed. RESULTS: Both women and men with a fracture of the distal forearm ran an increased risk of sustaining a subsequent hip fracture. The overall relative hazard for the women was 1.54 and for men 2.27. The increased risk in the women was independent of age at inclusion, but that in the men was more pronounced in the younger age groups. CONCLUSIONS: Patients with a fracture of the distal forearm run an increased risk of sustaining a subsequent hip fracture. They therefore appear to constitute a group in which appropriate prophylactic measures against osteoporosis and fractures should be considered.

Adult↗