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Biomedical subjects

Hans-Olov Adami

Publications and source records attributed to Hans-Olov Adami.

At least 19 recordsLinked to original sources

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↗

Atopy and risk of non-Hodgkin lymphoma.

BACKGROUND: A possible connection between allergy and cancer has been suspected, but allergy-related conditions or atopy have been inconsistently associated with reduced risks of non-Hodgkin lymphoma. We investigated this association in a population-based case-control study and in a prospective study with prediagnostic blood specimens. METHODS: We carried out a population-based study of 3055 case patients with non-Hodgkin lymphoma and 3187 control subjects in Denmark and Sweden, including questionnaire information on allergy and blood specimens, and a nested case-control study within a prospective cohort of more than 400,000 Finnish women. In the second study, serum specimens from the 198 case patients who developed non-Hodgkin lymphoma within a median of 8.9 years after the blood was drawn were matched with serum specimens from 594 control subjects. In both studies, laboratory-based evidence of allergy (atopy) was determined in serum on the basis of specific IgE reactivity to common inhalant allergens. Dissemination of disease was classified by the Ann Arbor system. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by logistic regression. RESULTS: In the first study, ever having hay fever, but not other allergic conditions, was associated with a reduced risk of non-Hodgkin lymphoma. In particular, subjects with specific IgE reactivity in serum had a 32% (95% CI = 20% to 42%) lower risk of overall non-Hodgkin lymphoma than those without such reactivity. However, among case patients, dissemination of the disease was strongly inversely associated with specific IgE reactivity. In the second (i.e., prospective) study, no association was found between non-Hodgkin lymphoma and specific IgE reactivity, except possibly immediately before a diagnosis of non-Hodgkin lymphoma (> or = 10 years before diagnosis, OR = 1.00, 95% CI = 0.48 to 2.09; 5-9 years before, OR = 0.95, 95% CI = 0.50 to 1.84; 1-4 years before, OR = 0.33, 95% CI = 0.11 to 1.02; and < 1 year before, OR = 0.27, 95% CI = 0.03 to 2.31). CONCLUSION: Allergy may not be causally associated with the risk of non-Hodgkin lymphoma. The inverse association observed in some case-control studies may arise because non-Hodgkin lymphoma suppresses the immunologic response to allergens.

Adult↗

The risk of pancreatic cancer in patients with gastric or duodenal ulcer disease.

Although Helicobacter pylori (H. pylori) seropositivity is linked to an excess risk of pancreatic cancer, the biologic mechanism is unknown. Gastric ulcer is primarily associated with corpus colonization of H. pylori, atrophic gastritis and formation of N-nitrosamines. Duodenal ulcer is a marker of antral colonization, hyperacidity and uninhibited secretin release. We estimated relative risks for pancreatic cancer among patients with gastric or duodenal ulcer, based on a register-based retrospective cohort study with 88,338 patients hospitalized for gastric ulcer and 70,516 patients for duodenal ulcer recorded in the Swedish Inpatient Register between 1965 and 2003. Following operation, the 14,887 patients who underwent gastric resection and 8,205 with vagotomy were analyzed separately. Multiple record-linkages allowed complete follow-up and identification of all incident cases of pancreatic cancer until December 31, 2003. Standardized incidence ratios (SIRs) estimated relative risks. During years 3-38 of follow-up, we observed a 20% excess risk (95% confidence interval [CI] 10-40%) for pancreatic cancer among unoperated gastric ulcer patients. The excess increased to 50% (95% CI 10-110%) 15 years after first hospitalization (p for trend = 0.03). SIR was 2.1 (95% CI 1.4-3.1) 20 years after gastric resection. Unoperated duodenal ulcer was not associated with pancreatic cancer risk, nor was vagotomy. Our results lend indirect support to the nitrosamine hypothesis, but not to the hyperacidity hypothesis in the etiology of pancreatic cancer.

Aged↗

Association of frequent consumption of fatty fish with prostate cancer risk is modified by COX-2 polymorphism.

Dietary intake of marine fatty acids from fish may protect against prostate cancer development. We studied this association and whether it is modified by genetic variation in cyclooxygenase (COX)-2, a key enzyme in fatty acid metabolism and inflammation. We assessed dietary intake of fish among 1,499 incident prostate cancer cases and 1,130 population controls in Sweden. Five single nucleotide polymorphisms (SNPs) were identified and genotyped in available blood samples for 1,378 cases and 782 controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression. Multiplicative and additive interactions between fish intake and COX-2 SNPs on prostate cancer risk were evaluated. Eating fatty fish (e.g., salmon-type fish) once or more per week, compared to never, was associated with reduced risk of prostate cancer (OR: 0.57, 95% CI: 0.43-0.76). The OR comparing the highest to the lowest quartile of marine fatty acids intake was 0.70 (95% CI: 0.51-0.97). We found a significant interaction (p < 0.001) between salmon-type fish intake and a SNP in the COX-2 gene (rs5275: +6365 T/C), but not with the 4 other SNPs examined. We found strong inverse associations with increasing intake of salmon-type fish among carriers of the variant allele (OR for once per week or more vs. never = 0.28, 95% CI: 0.18-0.45; p(trend) < 0.01), but no association among carriers of the more common allele. Frequent consumption of fatty fish and marine fatty acids appears to reduce the risk of prostate cancer, and this association is modified by genetic variation in the COX-2 gene.

Aged↗

Optimizing the design of web-based questionnaires--experience from a population-based study among 50,000 women.

BACKGROUND: Web-questionnaires are an important tool for future epidemiological research because these allow for rapid and cost-efficient assembly of self-reported information on risk factors and health outcomes. However, to achieve high response rates it is essential to accommodate factors that prevent drop out and so insure validity of future studies. We aim to study how socio-demographic variables as well as design issues such as the ordering and level of difficulty (Easy-to-hard vs. Hard-to-easy) of questions in a web-questionnaire affects the probability of drop out and non-response. METHOD: In 2003 we invited 47,859 women participating in an ongoing prospective study to a follow-up using a web-based mode. Two versions of the questionnaire existed, varying in level of difficulty (Easy-to-hard vs. Hard-to-easy). We report drop out (proportion non-completers) between groups defined by level of difficulty and estimated adjusted risk differences. RESULTS: The drop out differs significantly depending on the order of the questions in the web-questionnaire. The socio-demographic pattern among lurkers (participants that enter, start responding to, but do not complete a web-questionnaire) differs from that among completers of web-questionnaires. CONCLUSIONS: An additional 6% units of completers--persons initiating and completing the questionnaire--can be obtained by considering the ordering of questions. A group uniquely identified in web-surveys, as lurkers are potentially easier to persuade to complete an already started web-questionnaire compared to a non-responder. Lurkers thus constitute a unique opportunity of decreasing the drop out rate and therefore merit future research.

Cohort Studies↗

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↗

Dietary carotenoids and risk of colorectal cancer in a pooled analysis of 11 cohort studies.

Dietary carotenoids have been hypothesized to protect against epithelial cancers. The authors analyzed the associations between intakes of specific carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein + zeaxanthin, and lycopene) and risk of colorectal cancer using the primary data from 11 cohort studies carried out in North America and Europe. Carotenoid intakes were estimated from food frequency questionnaires administered at baseline in each study. During 6-20 years of follow-up between 1980 and 2003, 7,885 incident cases of colorectal cancer were diagnosed among 702,647 participants. The authors calculated study-specific multivariate relative risks and then combined them using a random-effects model. In general, intakes of specific carotenoids were not associated with colorectal cancer risk. The pooled multivariate relative risks of colorectal cancer comparing the highest quintile of intake with the lowest ranged from 0.92 for lutein + zeaxanthin to 1.04 for lycopene; only for lutein + zeaxanthin intake was the result borderline statistically significant (95% confidence interval: 0.84, 1.00). The associations observed were generally similar across studies, for both sexes, and for colon cancer and rectal cancer. These pooled data did not suggest that carotenoids play an important role in the etiology of colorectal cancer.

Carotenoids↗

Systematic replication study of reported genetic associations in prostate cancer: Strong support for genetic variation in the androgen pathway.

BACKGROUND: Association studies have become a common and popular method to identify genetic variants predisposing to complex diseases. Despite considerable efforts and initial promising findings, the field of prostate cancer genetics is characterized by inconclusive reports and no prostate cancer gene has yet been established. METHODS: We performed a literature review and identified 79 different polymorphisms reported to influence prostate cancer risk. Of these, 46 were selected and tested for association in a large Swedish population-based case-control prostate cancer population. RESULTS: We observed significant (P < 0.05) confirmation for six polymorphisms located in five different genes. Three of them coded for key enzymes in the androgen biosynthesis and response pathway; the CAG repeat in the androgen receptor (AR) gene (P = 0.03), one SNP in the CYP17 gene (P = 0.04), two SNPs in the SRD5A2 gene (P = 0.02 and 0.02, respectively), a deletion of the GSTT1 gene (P = 0.006), and one SNP in the MSR1 gene, IVS5-59C > A, (P = 0.009). CONCLUSIONS: Notwithstanding the difficulties to replicate findings in genetic association studies, our results strongly support the importance of androgen pathway genes in prostate cancer etiology.

Aged↗

The socioeconomic gradient in the incidence of stroke: a prospective study in middle-aged women in Sweden.

BACKGROUND AND PURPOSE: A socioeconomic gradient in stroke has been demonstrated in a variety of settings, but mostly in men. Our purpose was to establish whether a socioeconomic gradient in stroke existed in a group of Swedish women and whether this gradient could be explained by established stroke risk factors or psychosocial factors. METHODS: The Women's Lifestyle and Health Cohort Study includes 49 259 women from Sweden aged 30 to 50 years at baseline (1991 to 1992). The women completed an extensive questionnaire and were traced through linkages to national registries until the end of 2002. Among the 47 942 women included in these analyses, there were 200 cases of incident stroke during follow up (121 ischemic stroke, 47 hemorrhagic stroke, and 32 of unknown origin). Statistical analysis was through the Cox proportional hazards model. RESULTS: The risk of stroke was significantly inversely related to years of education completed, our proxy for socioeconomic status (hazard ratio comparing lowest with highest education group=2.1, 95% CI: 1.4 to 2.9, P for trend <0.001). This association was reduced after adjustment for established risk factors, although remaining significant (1.5, 1.0 to 2.2, P for trend=0.04). The gradient was more pronounced for ischemic stroke (2.9, 1.8 to 4.7, P for trend <0.001) than for hemorrhagic stroke (1.4, 0.7 to 2.9, P for trend=0.35). Job strain and social support were unrelated to risk of stroke. Self-rated health was strongly related to risk of stroke mediated by established risk factors. Psychosocial factors did not contribute toward the socioeconomic gradient in stroke. CONCLUSIONS: There was a strong gradient in risk of stroke by years of education, especially for ischemic stroke. Most of the social gradient was explained by established risk factors, particularly smoking and alcohol, but not by psychosocial factors.

Alcohol Drinking↗

Germ-line genetic variation in the key androgen-regulating genes androgen receptor, cytochrome P450, and steroid-5-alpha-reductase type 2 is important for prostate cancer development.

Prostate cancer risk may be influenced by single genetic variants in the hormone-regulating genes androgen receptor (AR), cytochrome P450 (CYP17), and steroid-5-alpha-reductase type 2 (SRD5A2). In this study, we comprehensively investigated polymorphisms in these three loci and their joint effect in a large population-based study. We selected 23 haplotype-tagging single-nucleotide polymorphisms (htSNP) that could uniquely describe >95% of the haplotypes (6 in AR, 6 in CYP17, and 11 in SRD5A2). These htSNPs were then genotyped in the Cancer Prostate in Sweden population (2,826 case subjects and 1,705 controls). We observed significant association for several SNPs in the AR gene (P = 0.004-0.02) and CYP17 (P = 0.009-0.05) and one SNP in SRD5A2 (P = 0.02). Carriers of the most common AR haplotype had a significant excess risk to develop prostate cancer [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 1.1-1.5; P = 0.002], yielding an estimated population attributable risk of 16% (95% CI, 0.06-0.25). Combining risk alleles from these genes yielded a 12% risk increase for each additional high-risk allele carried (95% CI, 1.1-1.2; P for trend = 9.2 x 10(-5)), with an overall OR of 1.87 (95% CI, 1.0-3.4) for carriers of all five included risk alleles, an OR of 2.13 (P for trend = 8 x 10(-4)) for advanced disease, and an OR of 4.35 (P for trend = 7 x 10(-5)) for disease onset before age 65 years. Genetic variation in key genes in the androgen pathway is important for development of prostate cancer and may account for a considerable proportion of all prostate cancers. Carriers of five high-risk alleles in the AR, CYP17, and SRD5A2 genes are at approximately 2-fold excess risk to develop prostate cancer.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

Dietary intake of phytoestrogens, estrogen receptor-beta polymorphisms and the risk of prostate cancer.

BACKGROUND: The causes of prostate cancer are poorly understood, but genetic factors may be more important than for many other malignancies, and dietary phytoestrogens may be protective. Because phytoestrogens bind tightly to the estrogen receptor-beta, we conducted an epidemiologic investigation of synergistic effects between phytoestrogen intake and estrogen receptor-beta gene polymorphisms. METHODS: We performed a population-based case-control study in Sweden. All participants reported their phytoestrogen intake and donated a blood sample. We identified four haplotype-tagging single nucleotide polymorphisms (htSNPs) and genotyped these htSNPs in 1314 prostate cancer patients and 782 controls. Odds ratios were estimated by multivariate logistic regression. Interactions between phytoestrogen intake and estrogen receptor-beta SNPs on prostate cancer risk were evaluated considering both multiplicative and additive effect scales. RESULTS: We found a significant multiplicative interaction (P = 0.04) between dietary intake of phytoestrogens and a promoter SNP in the estrogen receptor-beta gene (rs 2987983-13950), but not with any of the three other htSNPs (P = 0.11, 0.69, 0.85). Among carriers of the variant promoter alleles, we found strong inverse associations with increasing intake of total phytoestrogens (odds ratio for highest vs. lowest quartile = 0.43; P for trend <0.001), isoflavonoids (odds ratio = 0.63; P for trend = 0.05), and coumestrol (odds ratio = 0.57; P for trend = 0.003). We found no association between phytoestrogens and prostate cancer among carriers homozygous for the wild-type allele (TT). CONCLUSIONS: Our study provides strong evidence that high intake of phytoestrogens substantially reduce prostate cancer risk among men with specific polymorphic variation in the promoter region of the estrogen receptor-beta gene.

Adult↗

A comprehensive association study for genes in inflammation pathway provides support for their roles in prostate cancer risk in the CAPS study.

BACKGROUND: Recently identified associations of prostate cancer risk with several genes involved in innate immunity support a role of inflammation in the etiology of prostate cancer. Considering inflammation is regulated by a complex system of gene products, we hypothesize sequence variants in many other genes of this pathway are associated with prostate cancer. METHODS: We evaluated 9,275 SNPs in 1,086 genes of the inflammation pathway using a MegAllele genotyping system among 200 familial cases and 200 unaffected controls selected from a large Swedish case-control population (CAPS). RESULTS: We found that significantly more than the expected numbers of SNPs were significant at a nominal P-value of 0.01, 0.05, and 0.1, providing overall support for our hypothesis. The excess was largest when using a more liberal nominal P-value (0.1); we observed 992 significant SNPs compared with the 854 significant SNPs expected by chance, and this difference was significant based on a permutation test (P = 0.0025). We also began the effort of differentiating true associated SNPs by selecting a small subset of significant SNPs (N = 26) and genotyped these in an independent sample of approximately 1,900 CAPS1 subjects. We were able to confirm 3 of these 26 SNPs. It is expected that many more true associated SNPs will be confirmed among the 992 significant SNPs identified in our pathway screen. CONCLUSIONS: Our study provides the first objective support for an association between prostate cancer and multiple modest-effect genes in inflammatory pathways.

Aged↗

Nutrient intake and risk of non-Hodgkin's lymphoma.

The mechanisms through which diet may influence the development of non-Hodgkin's lymphoma (NHL) are unclear but can be better understood by examining associations between nutrient consumption and NHL risk. Between 2000 and 2002, 591 NHL cases and 460 population-based controls in Sweden completed a semiquantitative food frequency questionnaire. Unconditional logistic regression was performed to estimate odds ratios and 95% confidence intervals for associations with nutrient intake; all statistical tests were two sided. Dietary intake of most macronutrients was not associated with risk of NHL or its common subtypes. Consumption of omega-3 or marine fatty acids was associated with decreased risk of NHL and chronic lymphocytic lymphoma, and dietary fiber was associated with lower risk of all subtypes examined. When the highest and the lowest quartiles of marine fat intake were compared, the odds ratio for NHL risk was 0.6 (95% confidence interval: 0.4, 0.9), ptrend=0.03; for dietary fiber intake, the corresponding odds ratio was 0.5 (95% confidence interval: 0.3, 0.7), ptrend<0.001. Dietary consumption of beta-carotene or alpha-tocopherol was associated with lower NHL risk, whereas intake of calcium or retinol was associated with increased NHL risk. Nutrients that affect inflammation, vitamin D activity, oxidative DNA damage, or DNA methylation may be associated with risk of NHL.

Adolescent↗

Cancer risk among patients with condylomata acuminata.

Condylomata acuminata have been shown to increase the risk of anogenital cancers. However, previous studies have been of limited sample size and/or short follow-up duration, which prevent precise estimates of long-term excess risk, especially for specific cancer sites. We estimated the risk of specific cancers in a large cohort of hospitalized patients with condylomata acuminata, as recorded in the Swedish Inpatient Register between 1965 and 1999. Altogether, 10,971 patients (1,685 men and 9,286 women) were followed through 1999 for a median of 13 years. The standardized incidence ratio (SIR)--the ratio of the observed number of cancers to the number expected on the basis of the incidence in the Swedish population at large--was used as a measure of relative risk. After excluding the first-year of follow-up, we observed 43 cases of anogenital cancer in women, and 7 cases in men. Risks were elevated for cancers of the vulva (N = 13, SIR = 10.2, 95% confidence interval (CI) = 5.4-17.4), vagina (N = 4, SIR = 12.0, 95% CI = 3.3-30.7) and penis (N = 5, SIR = 21.9, 95% CI = 7.1-51.2). There was a moderate excess risk of cervical cancer in situ (N = 259, SIR = 1.9, 95% CI = 1.7-2.1), but not invasive cervical cancer. Excess risks of esophageal, buccal cavity, nonmelanoma skin, lung and bladder cancers, and Hodgkin and non-Hodgkin lymphoma, were also observed in both men and women. In conclusion, condylomata acuminata are strongly associated with increased risk of cancers of the vulva, vagina, penis and anus, as well as some nonanogenital malignancies, but not invasive cervical cancer.

Adult↗

Trends in incidence and mortality of nasopharyngeal carcinoma over a 20-25 year period (1978/1983-2002) in Sihui and Cangwu counties in southern China.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world but is common in southern China. A recent report from the Hong Kong Cancer Registry, a high-risk area for NPC in southern China, showed that incidence rate decreased by 29% for males and by 30% for females from 1980-1999, while mortality rate decreased by 43% for males and 50% for females. Changing environmental risk factors and improvements in diagnosis and treatment were speculated to be the major factors contributing to the downward trend of the incidence and mortality rates of NPC. To investigate the secular trends in different Cantonese populations with different socio-economic backgrounds and lifestyles, we report the incidences and mortality rates from two population-based cancer registries in Sihui and Cangwu counties from 1978-2002. METHODS: Incidence and mortality rates were aggregated by 5-year age groups and 5 calendar years. To adjust for the effect of difference in age composition for different periods, the total and age-specific rates of NPC incidence and mortality rate were adjusted by direct standardization according to the World Standard Population (1960). The Estimated Annual Percentage Change (EAPC) was used as an estimate of the trend. RESULTS: The incidence rate of NPC has remained stable during the recent two decades in Sihui and in females in Cangwu, with a slight increase observed in males in Cangwu from 17.81 to 19.76 per 100,000. The incidence rate in Sihui is 1.4-2.0 times higher during the corresponding years than in Cangwu, even though the residents of both areas are of Cantonese ethnicity. A progressive decline in mortality rate was observed in females only in Sihui, with an average reduction of 6.3% (p = 0.016) per five-year period. CONCLUSION: To summarize, there is great potential to work in the area of NPC prevention and treatment in southern China to decrease NPC risk and improve survival risk rates in order to reduce M:I ratios. Future efforts on effective prevention, early detection and treatment strategies were also discussed in this paper. Furthermore, the data quality and completeness also need to be improved.

Adult↗