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Biomedical subjects

H O Adami

Publications and source records attributed to H O Adami.

At least 91 records · Page 5Linked to original sources
PubMed1998

Parity, age at first birth and the risk of carcinoma in situ of the breast.

Epidemiological studies of in situ breast cancer are sparse, and the role of reproductive history, an established risk modifier for invasive breast cancer, remains incompletely investigated. To examine possible associations with parity and age at first birth, we undertook a case-control study nested in a nationwide cohort of Swedish women. The reproductive history of 1,368 women aged 65 or younger with a diagnosis of carcinoma in situ of the breast were compared with that of 6,837 age-matched controls drawn randomly from a population-based Fertility Registry. Statistical analyses were performed by conditional logistic regression. Compared to nulliparous women, ever-parous women were at a reduced risk of carcinoma in situ of the breast. The risk decreased with number of live births, with the estimated risk reduction in the highest parity group (5+), being of the same magnitude as that reported for invasive breast cancer. By contrast, a positive association with increasing age at first birth was somewhat less pronounced than that observed previously in the same data set with respect to invasive breast cancer. Our findings indicate that parity affects the risk of invasive breast cancer and carcinoma in situ similarly, whereas the effect of age at first birth appears to be weaker for the risk of carcinoma in situ.

Adult↗
PubMed1998

Insulin-like growth factor 1 and prostate cancer risk: a population-based, case-control study.

BACKGROUND: Recent epidemiologic investigations have suggested an association between increased blood levels of insulin-like growth factor 1 (IGF-1) and increased risk of prostate cancer. Our goal was to determine whether an association exists between serum levels of IGF-1 and one of its binding proteins, insulin-like growth factor-binding protein 3 (IGFBP-3), and prostate cancer risk. METHODS: An immunoradiometric assay was used to quantify IGF-1 levels and IGFBP-3 levels in serum samples as part of a population-based, case-control study in Sweden. The study population comprised 210 patients with newly diagnosed, untreated prostate cancer and 224 frequency-matched control subjects. Data were analyzed by use of unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Reported P values are two-sided. RESULTS: The mean serum IGF-1 level for case patients (158.4 ng/mL) was significantly higher than that for control subjects (147.4 ng/mL) (P = .02); corresponding mean serum IGFBP-3 levels were not significantly different between case patients (2668 ng/mL) and control subjects (2518 ng/mL) (P =.09). We found a moderately strong and statistically significant (P = .04) positive association between serum levels of IGF-1 levels and risk of prostate cancer (OR = 1.51; 95% CI = 1.0-2.26 per 100 ng/mL increment); the association was particularly strong for men younger than 70 years of age (OR = 2.93; 95% CI = 1.43-5.97). No association was found between serum IGF-1 levels and disease stage. Serum IGFBP-3 levels were not significantly associated with increased risk of disease, and adjustment for IGFBP-3 had little effect on the association between IGF-1 levels and risk of prostate cancer. CONCLUSION: Elevated serum IGF-1 levels may be an important predictor of risk for prostate cancer. However, our results do not support an important role for serum IGFBP-3 as a predictor of risk for this disease.

Aged↗
PubMed1998

Risk for endometrial cancer in relation to occupational physical activity: a nationwide cohort study in Sweden.

Notwithstanding its biologic plausibility, the association between physical activity and endometrial cancer has been analyzed in only a few epidemiological studies. Retrospective assessment of exposure and small sample size often hampers interpretation of published data. We studied risk for endometrial cancer in relation to physical activity at work in a large cohort of Swedish women identified in the nationwide censuses in 1960 and 1970, with jobs that could be consistently classified into one of 4 levels of physical demands. Follow-up from 1971 through 1989 was accomplished through record linkages. Multivariate Poisson regression models were used to estimate relative risk. The risk for endometrial cancer increased regularly with decreasing level of occupational physical activity (p for trend < 0.001), and was associated more strongly with activity in 1970 than in 1960. In multivariate analyses, adjusted for age at follow-up, place of residence, calendar year of follow-up, and social class, the relative risk among women with the same physical activity level in 1960 and in 1970 was 30% higher for sedentary as compared with high/very high activity level; (p for trend=0.04). The protective effect of physical activity appeared to be confined to women aged 50 to 69, among whom sedentary work was associated with a 60% higher risk than that observed among women estimated to be physically most active. The excess seemed to disappear within 10 years after a change in physical activity level. Although confounding cannot be ruled out in our data, occupational physical activity appears to reduce the risk for endometrial cancer.

Adult↗
PubMed1998

Body size in different periods of life and breast cancer risk in post-menopausal women.

Adult obesity has been associated with an increased risk of post-menopausal breast cancer, but it is unclear whether this relationship reflects a causal role of obesity during childhood and adolescence, of weight gain during adult life or of adult obesity per se. In a population-based case-control study in all of Sweden, we included 3,345 (84% of all eligible) women aged 50-74 years with invasive breast cancer, and 3,454 (82% of all selected) controls of similar age. Mailed questionnaires and telephone interviews were used to collect detailed information on anthropometric measures. Odds ratios were estimated through multiple logistic regression. Women with the leanest somatotype at age 7 had about a 3-fold higher risk of breast cancer than the most obese (P for trend 0.0009). A suggested protective effect of a high body mass at age 18 and a detrimental influence of body mass 1 year prior to data collection largely reflected the effect of weight gain after age 18, a strong predictor of breast cancer risk. Among women at least 20 years post menopause, those who had gained 30 kg or more since age 18 had an odds ratio of 2.04 (95% confidence interval 1.20-3.48) of breast cancer compared with those who had maintained their weight unchanged. The effect of weight gain was unequivocal among non-users but not among users of hormone replacement therapy. Our findings have important implications, suggesting weight preservation as a means for prevention of post-menopausal breast cancer as well as a causal role of childhood body build in breast cancer etiology.

Age Factors↗
PubMed1998

Risk of connective tissue disease and related disorders among women with breast implants: a nation-wide retrospective cohort study in Sweden.

OBJECTIVE: To examine the relation between connective tissue disease and related conditions and breast implants. DESIGN: Retrospective cohort study of all women in the Swedish national inpatient registry who underwent breast augmentation surgery with artificial implants during 1964-93, compared with women who underwent breast reduction surgery during the same period. SETTING: Sweden. SUBJECTS: 7442 women with implants for cosmetic reasons or for reconstruction after breast cancer surgery and 3353 women with breast reduction surgery. MAIN OUTCOME MEASURES: Subsequent hospitalisation for definite connective tissue diseases (rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, dermatomyositis, and Sjögren's syndrome) or related disorders. RESULTS: 29 women with implants were hospitalised for definite connective tissue disease compared with 25.5 expected based on general population rates (standardised hospitalisation ratio 1.1 (95% confidence interval 0.8 to 1.6)). There were no diagnoses of systemic sclerosis, and no significant excess in risk for polymyalgia rheumatica, fibromyalgia, and several related disorders. Among women who underwent breast reduction surgery, 14 were hospitalised for definite connective tissue disease compared with 10.5 expected (standardised hospitalisation ratio 1.3 (0.7 to 2.2)). Compared with the breast reduction group, women with breast implants showed a slight reduction for all definite connective tissue disease (relative risk 0.8 (95% confidence interval 0.5 to 1.4)). CONCLUSIONS: This large nationwide cohort study shows no evidence of association between breast implants and connective tissue disease.

Adult↗
PubMed1998

A prospective study of association of monounsaturated fat and other types of fat with risk of breast cancer.

BACKGROUND: Animal studies suggest that monounsaturated and polyunsaturated fat may have opposite effects on the risk of breast cancer. METHODS: We performed a population-based prospective cohort study, including 61,471 women aged 40 to 76 years from 2 counties in central Sweden who did not have any previous diagnosis of cancer; 674 cases of invasive breast cancer occurred during an average follow-up of 4.2 years. All subjects answered a validated 67-item food frequency questionnaire at baseline. Cox proportional hazards models were used to obtain adjusted rate ratio (RR) estimates with 95% confidence intervals (CIs). RESULTS: After mutual adjustment of different types of fat, an inverse association with monounsaturated fat and a positive association with polyunsaturated fat were found. The RR for each 10-g increment in daily intake of monounsaturated fat was 0.45 (95% CI, 0.22-0.95), whereas the RR for a 5-g increment of polyunsaturated fat was 1.69 (95% CI, 1.02-2.78); the increments correspond to approximately 2 SDs of intake in the population. Comparing the highest quartile of intake with the lowest, we found an RR of 0.8 (95% CI, 0.5-1.2) for monounsaturated fat and 1.2 (95% CI, 0.9-1.6) for polyunsaturated fat. Saturated fat was not associated with the risk of breast cancer. CONCLUSIONS: Our results indicate that various types of fat may have specific opposite effects on the risk of breast cancer that closely resemble the corresponding effects in experimental animals. Research investigations and health policy considerations should take into account the emerging evidence that monounsaturated fat might be protective for risk of breast cancer.

Adult↗
PubMed1998

Response rate to mailed epidemiologic questionnaires: a population-based randomized trial of variations in design and mailing routines.

Although self-administered questionnaires are major sources of information in epidemiology, comparatively little has been done to study practical aspects of design and mailing. The objective of this study was to evaluate various measures taken to increase the response rate. A questionnaire was mailed in July 1995 to a random sample (n = 2,000) of the Swedish population aged 20-79 years. Using a randomized factorial study design, the questionnaire and mailing procedures were changed in three ways: preliminary notification, length of the questionnaire, and mention of telephone contact. The overall questionnaire retrieval rate was 49%. Preliminary notification (adjusted odds ratio of receiving a completed questionnaire = 1.30, 95% confidence interval (CI) 1.08-1.56 relative to the absence of preliminary notification) and short length of the questionnaire (odds ratio = 1.24, 95% CI 1.04-1.48 relative to a long questionnaire) were both independently associated with a higher retrieval rate. Of eight possible combinations, the one comprising preliminary notification, a short questionnaire, and no mention of telephone contact gave the highest retrieval rate, 56%. The lowest retrieval rate, 40%, was observed for the combination of no preliminary notification, a long questionnaire, and mention of telephone contact. Young age, male sex, and urban residence significantly lowered the retrieval rate. Although there was a positive association between the questionnaire retrieval rate and partial nonresponse (missing answers in retrieved questionnaires), the marginal losses due to the latter did not cancel the gains by optimized mailing routines. Old age was the strongest determinant of partial nonresponse. The data provide evidence that design and mailing strategies, as well as demographic characteristics, may greatly influence the response rate of mailed epidemiologic questionnaires.

Adult↗
PubMed1998

Towards an understanding of breast cancer etiology.

We present an etiological model for breast cancer in humans, and we examine whether it accommodates the patterns of occurrence of this disease and the associated risk factors. The model has four components: (1) the likelihood of breast cancer occurrence depends on the number of cells at risk; (2) the number of target cells is partially determined early in life, perhaps even in utero; (3) while a pregnancy stimulates the replication of already initiated cells, it conveys long-term protection through structural changes, terminal cellular differentiation, and perhaps other mechanisms; and (4) in adult life, mammotropic hormones, in conjunction with their receptors, affect the number of target cells, the likelihood of retention of spontaneous somatic mutations, and the rate of expansion of initiated clones. The model accommodates several hypotheses but also allows new insights.

Adult↗
PubMed1998

Dairy products, calcium, phosphorous, vitamin D, and risk of prostate cancer (Sweden)

OBJECTIVES: Dairy products consistently have been associated with an increased risk of prostate cancer, yet the mechanism of this relationship remains unknown. Recent hypotheses propose that 1,25 dihydroxyvitamin D (1,25 D) is protective for prostate cancer. One study in the United States found that calcium consumption, which can lower circulating 1,25 D, was associated with higher risk of advanced prostate cancer, and we sought to address this hypothesis in a distinct population. METHODS: We analyzed data from a population-based case-control study of prostate cancer conducted in Orebro, Sweden, with 526 cases and 536 controls. Using unconditional logistic regression models, we examined the relationship of dairy products, dietary calcium, phosphorous, and vitamin D with risk of total, extraprostatic, and metastatic prostate cancer. RESULTS: Calcium intake was an independent predictor of prostate cancer (relative risk (RR) = 1.91, 95 percent confidence interval (CI) 1.23-2.97 for intake > or = 1183 vs. < 825 mg/day), especially for metastatic tumors (RR = 2.64, 95 percent CI 1.24-5.61), controlling for age, family history of prostate cancer, smoking, and total energy and phosphorous intakes. High consumption of dairy products was associated with a 50 percent increased risk of prostate cancer. CONCLUSIONS: Our results support the hypothesis that high calcium intake may increase risk of prostate cancer, and this relation may underlie previously observed associations between dairy products and prostate cancer.

Adult↗
PubMed1998

Recent trends in breast cancer incidence in Sweden.

Breast cancer incidence in Sweden during the period 1984-93 shows no clear trend in women aged below 40 years but a transient increase at ages 50-69 years, probably as a result of mammography screening. Our data give no indication that use of oral contraceptives or replacement hormones have affected nationwide breast cancer incidence rates.

Adult↗
PubMed1998

Benign anal lesions, inflammatory bowel disease and risk for high-risk human papillomavirus-positive and -negative anal carcinoma.

A central role in anal carcinogenesis of high-risk types of human papillomaviruses (hrHPV) was recently established, but the possible role of benign anal lesions has not been addressed in hrHPV-positive and -negative anal cancers. As part of a population-based case-control study in Denmark and Sweden, we interviewed 417 case patients (93 men and 324 women) diagnosed during the period 1991-94 with invasive or in situ anal cancer, 534 patients with adenocarcinoma of the rectum and 554 population controls. Anal cancer specimens (n = 388) were tested for HPV by the polymerase chain reaction. Excluding the 5 years immediately before diagnosis, men, but not women, with anal cancer reported a history of haemorrhoids [multivariate odds ratio (OR) 1.8; 95% confidence interval (CI) 1.04-3.2] and unspecific anal irritation (OR 4.5; CI 2.3-8.7) significantly more often than controls. Women with anal cancer did not report a history of benign anal lesions other than anal abscess to any greater extent than controls, but they had used anal suppositories more often (OR 1.5; CI 1.1-2.0). Patients with hrHPV in anal cancer tissue (84%) and those without (16%) reported similar histories of most benign anal lesions, but anal fissure or fistula was more common among hrHPV-positive cases. Ulcerative colitis and Crohn's disease, reported by <1% of study participants, were not associated with anal cancer risk. The higher proportion of hrHPV-positive anal cancers among case patients with anal fissure or fistula suggests that such mucosal lesions may provide direct viral access to basal epithelial layers. Since risk associations with benign anal lesions in men may be confounded by unreported sexual behaviour, and since risk associations in women were generally negative, it seems unlikely that benign anal lesions act as promoters in hrHPV-associated anal carcinogenesis. Moreover, benign anal lesions appear not to be linked to an alternative, hrHPV-unassociated causal pathway to anal cancer. Ulcerative colitis and Crohn's disease were not supported as causal factors for anal cancer.

Abscess↗
PubMed1998

Breast implants and risk of neurologic disease: a population-based cohort study in Sweden.

OBJECTIVE: To examine the risk of neurologic disorders among women with breast implants. BACKGROUND: Case reports in the literature have raised concern about a possible link between silicone breast implants and some types of neurologic disorders, but there is a dearth of epidemiologic studies in this area. METHODS: Through the nationwide Swedish hospital discharge register, we identified a population-based cohort of 7433 women with breast implants. A similarly identified cohort of 3351 women who underwent breast reduction surgery served as a comparison. The women were followed from 1972 (or date of breast surgery if it occurred later) through 1993 by means of record linkages and review of inpatient medical records. Ratios of observed to expected numbers, and relative risks (RR) with 95% confidence intervals (CI), were calculated as measures of the risk of neurologic diseases among women with implants. RESULTS: A direct comparison of the exposed (implant) versus comparison (breast reduction) groups, after exclusion of patients with pre-existing disease or incorrect neurologic diagnoses, showed no excess risk among implant patients (RR = 0.8; 95% CI = 0.5 to 1.4). When external rates derived from the background population were used as comparison, we found a small, statistically nonsignificant excess of neurologic disorders both in the breast implant (RR = 1.3; 95% CI = 0.9 to 1.9) and the breast reduction (RR = 1.5; 95% CI = 0.9 to 2.4) cohorts. CONCLUSION: Our results provide no support for the conjecture that breast implants cause neurologic disease.

Adult↗
PubMed1998

Factors associated with atypical nevi: a population-based study.

We conducted a case-control study to identify factors associated with the presence of clinically atypical nevi. Potential participants were selected, using a two-staged sampling scheme, from a population-based cohort of 50,000 Swedish women who had responded to a previous health survey questionnaire. Of 500 women sampled for study recruitment, 400 (80%) agreed to participate. Study participants underwent a physician-conducted skin examination, which identified 130 women who had at least one clinically atypical nevus (cases) and 270 women without these lesions (controls). The physician-conducted skin examination also assessed women for benign nevus counts; other risk factor information was based upon responses to a health survey questionnaire. We found a strong and highly statistically significant relationship between number of benign nevi and the presence of at least one clinically atypical nevus (P < 0.0001). Women with 100 or more benign nevi had a 26-fold increased likelihood of having an atypical nevus. We noted statistically significant interactions between number of benign nevi and other factors of interest; thus, the results are reported separately for women with low (<50) or high (> or =50) counts of benign nevi. Among women with low counts of benign nevi, the likelihood of having an atypical nevus increased with degree of freckling; there was also a suggested role for early sun exposure. Among women with high counts of benign nevi, difficulty tanning and lack of peeling sunburns between ages 10 and 19 appeared to increase the likelihood of case status; our data also suggested an inverse relationship between parity and atypical nevi in this subgroup.

Adult↗
PubMed1998

Childbearing and the risk of Hodgkin's disease.

The causes of Hodgkin's disease remain incompletely known, but a higher incidence in men than in women has prompted an interest in the role of female sex hormones and reproductive history. Available epidemiological data are, however, contradictory. We analyzed possible associations between parity, age at first birth, and the risk of developing Hodgkin's disease by a linkage between the Swedish Cancer Register and a nationwide Fertility Register. Among women born between 1925 and 1972, 917 cases with Hodgkin's disease and concomitant fertility information were identified. For each case patient, five age-matched controls were randomly selected among women in the Fertility Register. Conditional logistic regression was used to estimate odds ratios of Hodgkin's disease associated with a birth. We found a slightly and nonsignificantly reduced risk of Hodgkin's disease in ever-parous compared with nulliparous women. Among parous women, the number of children was unrelated to risk, whereas there was some evidence of an increased risk with late age at first birth in women under age 45 at diagnosis. No clear temporal relations between childbearing and subsequent risk were discernible in any parity or age group. Although uncontrolled confounding might have affected our results, they do not indicate that hormonal or immunological changes associated with childbearing play a role in the development of Hodgkin's disease.

Adult↗
PubMed1998

Cancer risk among Scandinavian immigrants in the US and Scandinavian residents compared with US whites, 1973-89.

Studies of migrants can generate hypotheses on the aetiology of cancer. Such studies are most informative when cancer incidence data are available both in the source and host country. We compared the incidence rate ratio of cancers (stomach, lung, female breast, colorectal and prostate) in Scandinavian immigrants to the US to US-born whites, using data from the SEER registry, 1973-89. Odds ratios (OR) for cancer sites in relation to birthplace were estimated using logistic regression. We also compared rate ratios (RR) for Scandinavian and US residents, using Poisson regression. Compared with US whites, most Scandinavian migrant groups had elevated OR for stomach cancer (1.58 to 3.92), and lower OR for lung cancer (0.38 to 0.88). Similarly, compared with US whites, residents of most Scandinavian countries had elevated RR for stomach cancer (1.47 to 3.33) and lower RR for lung cancer (0.27 to 0.97). Therefore, risk factors for lung and stomach cancers, such as smoking habits and Helicobacter pylori infection, respectively, may have been retained upon migration. Risks for breast, colorectal and prostate cancer among immigrants approached risks in the US (contrasting Scandinavian risks) suggesting assimilation of environmental and/or lifestyle factors.

Adolescent↗