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Biomedical subjects

Pär Stattin

Publications and source records attributed to Pär Stattin.

At least 19 recordsLinked to original sources
PubMed2007

Comprehensive evaluation of genetic variation in the IGF1 gene and risk of prostate cancer.

Insulin-like growth factor-I (IGF1) stimulates cell proliferation, decreases apoptosis, and has been implicated in cancer development. Epidemiological studies have shown elevated levels of circulating IGF1 to be associated with increased risk of prostate cancer. To what extent genetic variation in the IGF1 gene is related to prostate cancer risk is largely unknown. We performed a comprehensive haplotype tagging (HT) assessment of single nucleotide polymorphisms (SNPs) representing the common haplotype variation in the IGF1 gene. We genotyped 10 SNPs (9 haplotype tagging SNPs (htSNPs)) within Cancer Prostate in Sweden (CAPS), a case-control study of 2,863 cases and 1,737 controls, in order to investigate if genetic variation in the IGF1 gene is associated with prostate cancer risk. Three haplotype blocks were identified across the IGF1 gene and 9 SNPs were selected as haplotype tagging SNPs. Common haplotypes in the block covering the 3' region of the IGF1 gene showed significant global association with prostate cancer risk (p = 0.004), with one particular haplotype giving an odds ratio of 1.46 (95% CI = 1.15-1.84, p = 0.002). This haplotype had a prevalence of 5% in the study population. Our results indicate that common variation in the IGF1 gene, particularly in the 3' region, may affect prostate cancer risk. Further studies on genetic variations in the IGF1 gene in relation to prostate cancer risk as well as to circulating levels of IGF1 are needed to confirm this novel finding.

Case-Control Studies↗
PubMed2007

Castration-induced epithelial cell death in human prostate tissue is related to locally reduced IGF-1 levels.

BACKGROUND: Castration rapidly reduces stroma insulin-like growth factor (IGF)-1 synthesis and action in mouse prostate epithelium. We explore if similar changes are of importance for castration-induced prostate regression in humans. METHODS: Epithelial and surrounding stroma cells were micro-dissected from patient biopsies obtained before and shortly after castration. IGF-1 mRNA levels were quantified by RT-PCR and related to epithelial apoptosis and IGF-1, IGF-1 receptor, and androgen receptor (AR) immunoreactivity. RESULTS: IGF-1 mRNA was principally produced in the stroma and IGF-R1 in the epithelium. Stroma IGF-1 mRNA levels were significantly decreased after castration in non-malignant but not malignant tissue. Lack of stroma IGF-1 reduction after castration was associated with low stroma AR expression before therapy. Reduction of IGF-1 mRNA levels in the tumor stroma and/or epithelium was associated with epithelial apoptosis after therapy. CONCLUSIONS: Low AR expression and maintained stroma IGF-1 synthesis may result in limited tumor cell death after castration therapy.

Apoptosis↗
PubMed2007

Haplotype-based analysis of common variation in the growth hormone receptor gene and prostate cancer risk.

The growth hormone receptor (GHR) is potentially involved in prostate cancer through its role in stimulating insulin-like growth factor I production and its cellular effects on prostate epithelium. We have used a haplotype-based tagging approach within CAncer Prostate Sweden, a large retrospective case-control study of 2,863 cases and 1,737 controls to investigate if genetic variation in the GHR gene influences prostate cancer risk. One haplotype in the 3' region of the GHR gene was found associated with prostate cancer risk in elderly men (>65 years old at the time of diagnosis), with heterozygote haplotype carriers having an odds ratio of 1.65 (95% confidence interval, 1.21-2.16; P = 0.0009, P(corrected) = 0.03). GHR function has been implicated in the determination of body mass index. Interestingly, the same haplotype associated with risk in the 3' end of the GHR gene was also associated with a decrease in body mass index in controls (P = 0.003, P(corrected) = 0.05), possibly indicating some functionality with this haplotype. These results suggest that whereas genetic variation in the GHR gene does not seem to play a major role in prostate cancer etiology, one haplotype in the 3' region may be potentially relevant to cases with later onset of prostate cancer.

Aged↗
PubMed2006

Circulating enterolactone and risk of endometrial cancer.

It has been suggested that phytoestrogens protect against hormone-dependent cancers. Lignans are the main class of phytoestrogens in Western diets. We conducted a prospective study of endometrial cancer and circulating levels of the main human lignan, enterolactone. The design was a case-control study nested within 3 prospective cohort studies, in New York, Sweden and Italy. Serum or plasma samples had been collected at enrollment and stored at -80 degrees C. A total of 153 cases, diagnosed a median of 5.3 years after blood donation, and 271 matched controls were included. No difference in circulating enterolactone was observed between cases (median, 19.2 nmol/L) and controls (18.5 nmol/L). Adjusting for body mass index, the odds ratio for the top tertile of enterolactone, as compared to the lowest was 1.2 (95% CI, 0.7-2.0; p for trend = 0.53). Lack of association was observed in both pre- and postmenopausal women. No correlation was observed between enterolactone and circulating estrogens or SHBG in healthy postmenopausal women. These results do not support a protective role of circulating lignans, in the range of levels observed, against endometrial cancer.

4-Butyrolactone↗
PubMed2006

A potential inverse association between insulin-like growth factor I and hypertension in a cross-sectional study.

PURPOSE: Elevated circulating insulin-like growth factor I (IGF-I) levels increasingly are being implicated as a potential risk factor for the development of some cancers; however, relatively few epidemiologic studies have focused on potential relationships between circulating IGF-I levels and cardiovascular risk factors or cardiovascular disease. Hence, our objective is to examine relationships between IGF-I levels; body mass index (BMI); fasting insulin level; IGF binding protein 1 (IGFBP-1), IGFBP-2, and IGFBP-3 levels; and an array of traditional cardiovascular risk factors. METHODS: Our analysis included 715 men and women aged 30 to 62 years who participated in the Västerbotten Intervention Project cohort. IGF-I and IGFBP-1, -2, and -3 were measured in stored plasma samples. Cardiovascular risk factors of interest included glucose level (fasting and 2-hour postload), lipid levels (total cholesterol, high-density lipoprotein cholesterol, and triglycerides), blood pressure (systolic and diastolic), and hypertension status. All presented results were adjusted for age, sex, and laboratory batch. RESULTS: IGF-I quartile was associated inversely with 2-hour glucose level and diastolic blood pressure. There was a stepwise inverse graded association between increasing IGF-I quartile and hypertension, with an odds ratio of 0.51 (95% confidence interval, 0.29-0.90) for hypertension comparing the fourth IGF-I quartile with the first. Further adjusting for BMI and IGFBP-3 level simultaneously strengthened the inverse association, with an odds ratio of 0.42 (95% confidence interval, 0.22-0.80) for hypertension comparing the fourth with the first IGF-I quartile. CONCLUSIONS: Contrary to positive associations between IGF-I levels and some cancers, our results suggest that IGF-I level may be related inversely to prevalent hypertension, a risk factor for cardiovascular disease.

Adult↗
PubMed2006

Body mass index and cancer: results from the Northern Sweden Health and Disease Cohort.

Excess weight has been associated with increased risk of cancer. The effect of body mass index (BMI, kg/m(2)) on overall cancer risk and on risk of developing several common cancer types was examined in a population-based cohort study. Height and weight measurements were available for 35,362 women and 33,424 men recruited in the Northern Sweden Health and Disease Cohort between 1985 and 2003. Among cohort members, 2,691 incident cancer cases were identified. The association of BMI with cancer risk was examined using Poisson regression. Women with BMI > 27.1 (top quartile) had a 29% higher risk of developing any malignancy compared to women with BMI of 18.5-22.2 (lowest quartile), which increased to 47% in analysis limited to nonsmokers. Analyses according to WHO cut-off points showed that obese women (BMI > or = 30) had a 36% higher risk of cancer than women with BMI in the normal range (18.5-25). Individual cancer sites most strongly related to obesity were endometrium (risk for top quartile = 3.53, 95% confidence interval 1.86-7.43), ovary (2.09, 1.13-4.13) and colon (2.05, 1.04-4.41). BMI was inversely related to breast cancer occurring before age 49 (0.58, 0.29-1.11, p(trend) < 0.04). In men, there was no association of BMI with overall cancer risk. Obese men (BMI > or = 30), however, were at increased risk of developing kidney cancer (3.63, 1.23-10.7) and, after exclusion of cases diagnosed within 1 year of recruitment, colon cancer (1.77, 1.04-2.95). Our study provides further evidence that BMI is positively associated with cancer risk. In women from northern Sweden, up to 7% of all cancers were attributable to overweight and obesity and could be avoided by keeping BMI within the recommended range.

Adult↗
PubMed2005

The magnitude of early castration-induced primary tumour regression in prostate cancer does not predict clinical outcome.

INTRODUCTION: This study was designed to test whether early castration-induced short-term cellular changes in primary prostate tumours could predict clinical outcome in advanced disease. PATIENTS AND METHODS: Biopsies from 83 patients obtained before and within two weeks after surgical castration were investigated. Tumour epithelial cell apoptosis, proliferation, and prostate specific antigen (PSA) levels were quantified using immunohistochemistry, laser capture micro-dissection, and real time RT-PCR. Cellular effects were related to changes in serum PSA levels and clinical outcome. RESULTS: Decreased proliferation and PSA mRNA levels, and increased apoptosis were observed in most tumours. These early cellular responses were not correlated to each other and did not predict serum PSA response or cancer-specific survival. A nadir PSA level below 1 ng/ml predicted a longer cancer-specific survival after castration therapy. CONCLUSION: Castration therapy causes primary tumour regression in most patients with advanced prostate cancer, but these primary tumour effects are not predictive for systemic disease control. Studies of early changes in metastases during hormonal therapy will probably give more predictive information for clinical outcome than further studies in primary tumours.

Aged↗
PubMed2005

Cell proliferation and apoptosis in prostate tumors and adjacent non-malignant prostate tissue in patients at different time-points after castration treatment.

BACKGROUND: Androgen ablation is the standard treatment for advanced prostate cancer but the short-term cellular effects are largely unknown. METHODS: Sextant prostate biopsies were taken from 77 prostate cancer patients before and 1-10 days after castration treatment. Apoptosis, cell proliferation, and morphology were studied in malignant and non-malignant tissue, using stereological and immunohistochemical methods. RESULTS: Epithelial cell proliferation was significantly decreased both in non-malignant and malignant epithelium already 1 day after therapy. It remained low until day 7, but increased thereafter in the remaining non-malignant epithelial cells and in some tumors. Epithelial cell apoptosis was significantly increased during the first week and then returned to basal levels. The maximal apoptotic indexes, seven- and two-times the intact levels in the non-malignant and malignant glands, respectively, were found at days 3-4 or even earlier in the tumors. Signs of tumor shrinkage such as glandular collapse and decreased tumor cell size were observed from day 3 in most tumors. DISCUSSION: The present study shows that the magnitude and kinetics of the response to castration in the normal human prostate is very similar to the response previously described in rodents. We also demonstrate that most human prostate tumors rapidly respond to castration indicating the need for further evaluation of when and how to best monitor the effects of hormone ablation therapy in prostate cancer patients.

Aged↗
PubMed2005

Angiopoietin 2 expression is related to histological grade, vascular density, metastases, and outcome in prostate cancer.

BACKGROUND: In several malignant tissues, the angiopoietins are principal regulators of vascular growth and regression, but in normal prostate and prostate tumors the role of the angiopoietins is unknown. METHODS: Angiopoietin (ang) 1 and 2 were immunolocalized in TUR-diagnosed prostate tumors with long follow-up and the expression was related to vascular density and clinicopathological variables. RESULTS: Ang 1 was strongly expressed in the basal epithelial cell layer in non-malignant tissue, whereas tumors had lower levels localized to the epithelial cells. A weak ang 2 immunoreaction was observed in non-malignant tissue and in low to intermediate Gleason score (GS) tumors, with a similar expression pattern. However, most high GS tumors showed an intense ang 2 staining. Ang 2 was significantly correlated to GS, density of endoglin stained blood vessels, metastases, and to cancer specific survival. CONCLUSIONS: We conclude that ang 2 probably is an important regulator of angiogenesis in prostate cancer.

Aged↗
PubMed2005

Plasma folate, vitamin B12, and homocysteine and prostate cancer risk: a prospective study.

The role of folate metabolism in cancer development is a topic of much current interest, with maintenance of adequate folate status tending to show a protective effect. Aberrant methylation, primarily hypermethylation of certain genes including tumor suppressors, has been implicated in prostate cancer development. Folate, vitamin B12 and homocysteine are essential for methyl group metabolism and thus also for DNA methylation. We related plasma levels of these factors to prostate cancer risk in a prospective study of 254 case subjects and 514 matched control subjects. Increasing plasma levels of folate and vitamin B12 were statistically significantly associated with increased prostate cancer risk, with an odds ratio of 1.60 (95% CI = 1.03-2.49; p(trend) = 0.02) for folate and 2.63 (95% CI = 1.61-4.29; p(trend) < 0.001) for vitamin B12 for highest vs. lowest quartile. Increasing plasma homocysteine levels were associated with a reduced risk of borderline significance (OR = 0.67; 95% CI = 0.43-1.04; p(trend) = 0.08). After adjustment for the other 2 plasma variables, body mass index and smoking, a statistically significant increased risk remained only for vitamin B12 (OR = 2.96; 95% CI = 1.58-5.55; p(trend) = 0.001). Adjusted OR for folate and homocysteine were 1.30 (95% CI = 0.74-2.24; p(trend) = 0.17) and 0.91 (95% CI = 0.51-1.58; p(trend) = 0.60), respectively. Our results suggest that factors contributing to folate status are not protective against prostate cancer. On the contrary, vitamin B12, associated with an up to 3-fold increase in risk, and possibly also folate, may even stimulate prostate cancer development. These findings are novel and should be explored further in future studies.

Adult↗
PubMed2005

Tumor size, vascular density and proliferation as prognostic markers in GS 6 and GS 7 prostate tumors in patients with long follow-up and non-curative treatment.

OBJECTIVES: To investigate the prognostic value of potential markers in localized, Gleason score 6 and 7 prostate cancer (PC). METHODS: From a consecutive series of men with PC diagnosed at transurethral resection (1975-1990), specimens from 132 patients without metastases, with Gleason score (GS) 6 (n=80) or 7 (n=52) tumors followed with watchful waiting were examined. The fraction of resected prostate tissue containing cancer, the micro-vessel density (v.d.) when stained for endoglin or von Willebrand factor (vWf), and the percentage of Ki-67 labeled tumor cells were measured using immunohistochemistry. RESULTS: High levels of vWf v.d., endoglin v.d., and percent cancer of the TURP specimen were significantly associated with short cancer-specific survival in Kaplan-Meier analysis of all patients with GS 6 and 7 tumors. Interestingly, a combined estimate of percent cancer and vWF v.d. could be used to identify a large subset (50%) of GS 6 tumors with only a 2.5% risk of PC death within 15 years. None of the tested markers gave independent prognostic information for the GS 7 tumors. CONCLUSIONS: Estimates of tumor size and vascular density may identify a large proportion of non-aggressive GS 6, but not GS 7, tumors.

Age Factors↗
PubMed2005

Geographical variation in incidence of prostate cancer in Sweden.

OBJECTIVE: To investigate the geographical variation in prostate cancer incidence in Sweden, in particular the incidences of screening-detected tumours and curative treatment of prostate cancer. MATERIAL AND METHODS: Data were retrieved from the National Prostate Cancer Register of Sweden for all cases of prostate cancer diagnosed in the year 2000-01. There were a total of 14 376 cases of prostate cancer and the mean total annual age-adjusted incidence was 197/100 000 men. There were 3318 cases in tumour category T1c, i.e. non-palpable tumours diagnosed during work-up for an elevated serum level of prostate-specific antigen, 1006 of which (30%) were asymptomatic and detected at a health check-up. RESULTS: The difference between the counties with the lowest and highest age-adjusted incidences per 100 000 men of total prostate cancer was almost twofold (128 vs 217). The corresponding variation in incidence of category T1c tumours was more than fourfold (13 vs 60); the difference in incidence of T1c tumours detected in asymptomatic men was up to 10-fold (2 vs 20); and there was more than a fourfold variation in incidence of curative treatment between counties (13 vs 67). Measured incidences were mostly highest in urban regions and in counties with university hospitals. CONCLUSION: There are large geographical variations in prostate cancer incidence and in the frequency of curative treatment for prostate cancer in Sweden and there appear to be large geographical variations in the uptake of prostate cancer screening.

Aged↗
PubMed2005

The National Prostate Cancer Register in Sweden 1998-2002: trends in incidence, treatment and survival.

OBJECTIVES: To provide a descriptive review of the establishment of the National Prostate Cancer Register (NPCR) in Sweden, to present clinical characteristics at diagnosis and to calculate the relative survival of different risk groups after 5 years. MATERIAL AND METHODS: Since 1998, data on all newly diagnosed prostate cancers, including TNM classification, grade of malignancy, prostate-specific antigen (PSA) level and treatment, have been prospectively collected. For the 35,223 patients diagnosed between 1998 and 2002, relative survival in different risk groups has been calculated. RESULTS: Between 1998 and 2002, 96% of all prostate cancer cases diagnosed in Sweden were registered in the NPCR. The number of new cases increased from 6137 in 1998 to 7385 in 2002. The age-standardized rate rose in those aged < 70 years, while it was stable, or possibly declining from 1999, in the older age groups. The proportion of T1c tumours increased from 14% to 28% of all recorded cases. The age-adjusted incidence of advanced tumours (M1 or PSA > 100 ng/ml) decreased by 17%. The proportion of patients receiving curative treatment doubled. Patients with N1 or M1 disease or poorly differentiated tumours (G3 or Gleason score 8-10) had a markedly reduced relative 5-year survival rate. CONCLUSIONS: It is possible to establish a nationwide prostate cancer register including basic data for assessment of the disease in the whole of Sweden. The introduction of PSA screening has increased the detection of early prostate cancer in younger men and, to a lesser extent, decreased the incidence of advanced disease. The effect of these changes on mortality is obscure but the NPCR in Sweden will serve as an important tool in such evaluation.

Age Distribution↗
PubMed2005

IGF-I, IGFBP-3 and breast cancer in young women: a pooled re-analysis of three prospective studies.

Prospective cohort studies on breast cancer risk among premenopausal women and insulin-like growth factor I (IGF-I) concentrations have so far included only few cases, and have shown inconsistent relative risk estimates. We pooled 220 cases of breast cancer diagnosed before age 50, and 434 control subjects, from three prospective studies in New York (USA), Umeå (Northern Sweden) and Milan (Italy), and we measured IGF-I and insulin-like growth factor binding protein 3 (IGFBP-3) with common enzyme-linked immunosorbent assays. Overall, IGF-I and IGFBP-3 measurements obtained by the common method showed a positive but not significant relationship with breast cancer risk (odds ratios (ORs) 0.90 [95% confidence intervals (95% CI) 0.50-1.62], 1.63 [0.89-2.97], 1.46 [0.78-2.73] and 1.41 [0.75-2.63] for quintiles of IGF-I, and ORs 0.98 [0.54-1.75], 1.06 [0.59-1.91], 1.04 [0.58-1.87] and 1.77 [0.97-3.24] for quintiles of IGFBP-3). Our results give only moderate support for an association of blood IGF-I with breast cancer risk in young women.

Adult↗
PubMed2005

Chlamydial antibodies and risk of prostate cancer.

OBJECTIVE: We assessed the risk of prostate cancer by exposure to Chlamydia trachomatis. METHOD: Seven hundred thirty eight cases of prostate cancer and 2,271 matched controls were identified from three serum sample banks in Finland, Norway, and Sweden by linkage to the population based cancer registries. RESULTS: A statistically significant inverse association (odds ratio, 0.69; 95% confidence interval, 0.51-0.94) was found. It was consistent by different serotypes and there was a consistent dose-response relationship. CONCLUSION: C. trachomatis infection is not likely to increase the risk of prostate cancer. Whether the inverse relationship is true or due to difficulties in measuring the true exposure in prostatic tissue by serology, confounders or other sources of error remain open.

Adult↗
PubMed2005

Human papillomavirus 16, 18, and 33 infections and risk of prostate cancer: a Nordic nested case-control study.

Epidemiologic evidence of sexual history has emerged as a consistently found risk factor for prostate cancer. Some studies have reported an association between human papillomavirus (HPV) infections and prostate cancer. We did a nested case-control study within cohorts of more than 200,000 men enrolled in three Nordic biobanking projects. Follow-up using cancer registry linkages identified 804 prospectively occurring prostate cancer cases. Four control subjects per case were randomly selected from eligible sets of matched subjects that were alive and free of cancer at the time of diagnosis of the corresponding case and were matched to cases on biobank cohort, age (+/-2 years), county of residence, and date of blood sampling (+/-2 months in the Finnish and Swedish cohorts, +/-6 months in the Norwegian cohort). The serum samples were analyzed by standard ELISAs for the presence of immunoglobulin G antibodies against HPV types 16, 18, and 33. The joint HPV-16/HPV-18/HPV-33 seroprevalence in the joint cohort was 13.4% (107 of 799) among cases and 14.0% (363 of 2,596) among controls (odds ratio, 0.94; 95% confidence interval, 0.74-1.19). There were no noteworthy differences when the data were analyzed by different HPV type, country, or antibody levels. Our data do not support an association between serologic markers of HPV-16, HPV-18, and HPV-33 infections and risk of prostate cancer.

Adult↗
PubMed2005

Anticancer effects of a plant lignan 7-hydroxymatairesinol on a prostate cancer model in vivo.

Clinical intervention studies and experimental studies with lignan-rich diets suggest that lignans may have inhibitory effects on prostate cancer, but no clinical or experimental studies with purified lignans have been published. The purpose of this study was to investigate the effect of a plant lignan 7-hydroxymatairesinol (HMR) on LNCaP human prostate cancer xenografts in athymic mice. Athymic nude male mice were injected subcutaneously with LNCaP cells. Starting 3 days after tumor cell injections, a control diet or a control diet supplemented with 0.15% or 0.30% of HMR was administered to mice and the tumor take rate and growth was observed for 9 weeks. HMR diet inhibited the growth of LNCaP tumors. Mice treated with HMR had smaller tumor volume, lower tumor take rate, increased proportion of nongrowing tumors, and higher tumor cell apoptotic index compared with controls. Furthermore, the cell proliferation index was reduced in mice receiving the 0.30% HMR diet compared with mice receiving the control diet. Our results suggest that dietary HMR started at the early phase of the tumor development inhibits the growth of the LNCaP human prostate cancer xenografts in athymic male mice.

Animals↗