Nordic countries' data offer a unique possibility to evaluate the long-term benefit of cervical cancer screening in a context of increasing risk of human papillomavirus infection.
Ad hoc-refined age-period-cohort models were applied to the last 50-year incidence data from Denmark, Finland, Norway and Sweden to project expected cervical cancer cases in a no-screening scenario.
In the absence of screening, projected incidence rates for 2006-2010 in Nordic countries would have been between 3 and 5 times higher than observed rates. Over 60,000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.
Our study suggests that screening programmes might have prevented a HPV-driven epidemic of cervical cancer in Nordic countries. According to extrapolations from cohort effects, cervical cancer incidence rates in the Nordic countries would have been otherwise comparable to the highest incidence rates currently detected in low-income countries.
Possible risk factors for abnormal Papanicolaou smear were investigated in a population-based cross-sectional study. From Nuuk (Greenland) and Nykøbing Falster (Denmark), random samples of 800 women aged 20-39 years were drawn. Totals of 586 and 661 women were included in Greenland and Denmark, respectively. All women went through a personal interview, and had a gynecologic examination including a PAP smear and cervical swab for HPV analysis. A blood sample was taken for analysis of HSV type specific antibodies. Multiple sexual partners was the most important risk factor for abnormal cervical cytology (OR = 4.2). An infectious etiology was also indirectly supported by a relatively protective effect of barrier contraceptive methods (OR = 0.6). The simultaneous finding of HPV 16/18 as a significant risk factor (OR = 2.4) cannot be taken uncritically as support for a causal effect of this HPV type, since such a relationship between cytological changes of the cervix and HPV infection could also emerge if the positive PAP smear was not just a measure of intra-epithelial neoplasia but also an expression of the infection itself on the cervix.
To explore the etiology of testicular cancer, cases of testicular cancer were identified among members of a cohort of Danish boys born between 1941 and 1957 (inclusive), who had attended schools in Copenhagen and Gentofte and whose school health records were contained in an archive under the supervision of the Danish Cancer Registry. One hundred and eighty-three cases of testicular cancer diagnosed before 31 December 1984 were identified; 366 controls, matched to cases by sex and age, were selected from the same cohort. Information on potential risk factors and confounders was obtained from two sources: school health records and midwife protocols, both of which were recorded prior to the diagnosis of testicular cancer in cases. Relative risks (RR) approximated by the odds ratios were calculated and, in logistic regression analyses, adjustments were done for known or suspected confounders. A decreasing risk of testicular cancer with increasing birth order was observed (P = 0.020). Compared with being firstborn, being number four or more in birth order was associated with a significantly decreased RR for all testicular cancers (RR = 0.3, 95 percent confidence interval [CI] = 0.3-0.8) and testicular seminoma (RR = 0.1, CI = 0.02-0.9). No association was observed between high social class and the risk of testicular cancer (RR = 1.4, CI = 0.8-2.3); neither was age at which the study subjects had mumps or measles related to risk of testicular cancer. No cases of mumps orchitis were observed before or during school years. A slightly increased RR for testicular cancer among boys from small families could be explained by the association between family size and birth order.(ABSTRACT TRUNCATED AT 250 WORDS)
In the search for possible causes for the enormous increase in testicular cancer incidence in Denmark, we tested the hypothesis that a high fat or calorie intake in adolescence and consequently relative obesity is a promotional factor for testicular cancer. A total of 438 cases and three controls for each case were included in the study. Data originated from health examination of men liable for military service. Data were analysed by logistic regression analysis. No systematic statistically significant differences in body measurements [height, weight and body-mass index (weight/height2)] could be shown. Rather than being obese a slight trend was observed towards the future victims of testicular cancer being lighter, smaller and thinner than unaffected controls.
BACKGROUND: Obesity is associated with endocrine changes (e.g., increased estrogen and decreased testosterone in the blood) that have been implicated in the cause of prostate cancer and, therefore, an association between body weight and the risk of developing prostate cancer would be expected. However, because of bias or low statistical power in previous epidemiologic studies, associations between anthropometric measurements (height and weight), body mass index (BMI), and the risk of prostate cancer may have been inadvertently overlooked. PURPOSE: We performed a large, retrospective cohort study among Swedish construction workers to evaluate possible associations of adult weight, height, BMI, and lean body mass (LBM) by age at entry in the study with the incidence and mortality rate of prostate cancer. METHODS: We analyzed data that had been compiled in a computerized central register on a cohort of approximately 135000 male construction workers. Information on height and weight had been collected with the use of a comprehensive questionnaire filled out by nurses at the time of enrollment in the cohort, from 1971 through 1975. Complete follow-up was achieved through 1991 by means of record linkage to the Swedish National Cancer Register, the Death Register, and the Migration Register. A total of 2368 incident cases and 708 deaths from prostate cancer occurred in the cohort during a follow-up period averaging 18 years. We used only information obtained at the index visit from 1971 through 1975 to determine age-adjusted rate ratios (RRs) in a Poisson-based multiplicative multivariate model with age and the relevant exposure variable (e.g., weight, height, BMI, and LBM) as independent variables. RESULTS: All anthropometric measurements were positively associated with the risk of prostate cancer and were more strongly related to mortality than to incidence. The excess risk of death from prostate cancer was statistically significant in all BMI categories above the reference category: RR = 1.40 (95% confidence interval [CI] = 1.09-1.81) in the highest category compared with the lowest (P for trend = .04). For height and LBM, the excess risk in the highest compared with the lowest categories was somewhat less pronounced: RR = 1.28 (95% CI = 1.02-1.60) and RR = 1.26 (95% CI = 1.02-1.57), respectively. Statistically significant linear dose-response relationships were also found with the incidence of prostate cancer, with the exception of BMI (P for trend = .10). CONCLUSION: Our large cohort study indicates that various aspects of body size are related to the risk of prostate cancer and that future studies are needed to study the role of body size and prostate cancer.
In a retrospective study of 581 patients with a diagnosis of Bowen's disease (BD) treated over a 40-year period, we traced patient records to identify later diagnoses of nonskin cancer. Fifty patients had nonskin cancer, as against an expected number of 40, but this difference was not significant. The lack of association was equally true for BD on sun-exposed and non-sun-exposed skin. Our findings support the view that BD is not a skin marker for internal malignant disease.
The incidence of breast cancer among 1240 women who were treated surgically for breast hypertrophy in Copenhagen, Denmark between 1943 and 1971 was determined and compared with age- and calendar period-specific rates for the Danish female population. A total of 32 cases of breast cancer had developed by the end of 1990; the expected number was 52.55, yielding a relative risk (RR) of 0.61 [95% confidence interval (CI) 0.42-0.86]. The greatest reduction in risk was observed for women who had 600 g or more of breast tissue removed (RR=0.30; 95% CI 0.10-0.69). This suggests that the number of potential foci is important for cancer development in the female breast. In the group of women who were operated on before the age of 20, four cases of breast cancer developed, compared with 2.23 expected cases, to give an RR of 1.79, suggesting that the aetiology of their breast hypertrophy may be different from that for the rest of the group.
The purpose of the present study is to evaluate the possible association between bronchitis and exposure to man-made mineral fibres. The basis of the study has been cross-sectional data from the early 70's describing some 135,000 male Swedish construction workers. Data included information about exposure to asbestos and man-made mineral fibres, smoking habits and questions concerning symptoms of bronchitis. In non-smokers the rate-ratio of people exposed at least 3 years to non-exposed people is 2.68. In former smokers and in present smokers the corresponding values are 1.67 and 1.51 respectively.