OBJECTIVES:Incidence rates for testicular cancer have risen over the last few decades. Findings of an association between the risk of testicular cancer and social factors are controversial. The association of testicular cancer and different indicators of social factors were examined in this study.DESIGN:Case-control study.SETTING:Population-based multicentre study in four German regions (city states Bremen and Hamburg, the Saarland region and the city of Essen).PARTICIPANTS:The study included 797 control participants and 266 participants newly diagnosed with testicular cancer of which 167 cases were classified as seminoma and 99 as non-seminoma. The age of study participants ranged from 15 to 69 years.METHODS:Social position was classified by educational attainment level, posteducational training, occupational sectors according to Erikson-Goldthorpe-Portocarrero (EGP) and the socioeconomic status (SES) on the basis of the International SocioEconomic Index of occupational status (ISEI). ORs and corresponding 95% CIs (95% CIs) were calculated for the whole study sample and for seminoma and non-seminoma separately.RESULTS:Testicular cancer risk was modestly increased among participants with an apprenticeship (OR=1.7 (95% CI 1.0 to 2.8)) or a university degree (OR=1.6 (95% CI 0.9 to 2.8)) relative to those whose education was limited to school. Analysis of occupational sectors revealed an excess risk for farmers and farm-related occupations. No clear trend was observed for the analyses according to the ISEI-scale.CONCLUSIONS:Social factors based on occupational measures were not a risk factor for testicular cancer in this study. The elevated risk in farmers and farm-related occupations warrants further research including analysis of occupational exposures.

Objectives Male breast cancer is a rare disease of largely unknown aetiology. In addition to genetic and hormone-related risk factors, a large number of environmental chemicals are suspected of playing a role in breast cancer. The identification of occupations or occupational exposures associated with an increased incidence of breast cancer in men may help to identify mammary carcinogens in the environment.Methods Occupational risk factors for male breast cancer were investigated in a multi-centre case-control study conducted in eight European countries which included 104 cases and 1901 controls. Lifetime work history was obtained during in-person interviews. Occupational exposures to endocrine disrupting chemicals (alkylphenolic compounds, phthalates, polychlorinated biphenyls and dioxins) were assessed on a case-by-case basis using expert judgement.Results Male breast cancer incidence was particularly increased in motor vehicle mechanics (OR 2.1, 95% CI 1.0 to 4.4) with a dose-effect relationship with duration of employment. It was also increased in paper makers and painters, forestry and logging workers, health and social workers, and furniture manufacture workers. The OR for exposure to alkylphenolic compounds above the median was 3.8 (95% CI 1.5 to 9.5). This association persisted after adjustment for occupational exposures to other environmental oestrogens.Conclusion These findings suggest that some environmental chemicals are possible mammary carcinogens. Petrol, organic petroleum solvents or polycyclic aromatic hydrocarbons are suspect because of the consistent elevated risk of male breast cancer observed in motor vehicle mechanics. Endocrine disruptors such as alkylphenolic compounds may play a role in breast cancer.

Recent case-control studies suggested that dairy product consumption is an important risk factor for testicular cancer. We examined the association between consumption of dairy products, especially milk, milk fat, and galactose, and testicular cancer in a population-based case-control study including 269 case and 797 controls (response proportions of 76% and 46%, respectively). Dietary history was assessed by food frequency questions for the index persons and through their mothers including diet 1 year before interview and diet at age 17 years. We used conditional logistic regression to calculate odds ratios as estimates of the relative risk (RR), 95% confidence intervals (95% CI), and to control for social status and height. The RR of testicular cancer was 1.37 (95% CI, 1.12-1.68) per additional 20 servings of milk per month (each 200 mL) in adolescence. This elevated overall risk was mainly due to an increased risk for seminoma (RR, 1.66; 95% CI, 1.30-2.12) per additional 20 milk servings per month. The RR for seminoma was 1.30 (95% CI, 1.15-1.48) for each additional 200 g milk fat per month and was 2.01 (95% CI, 1.41-2.86) for each additional 200 g galactose per month during adolescence. Our results suggest that milk fat and/or galactose may explain the association between milk and dairy product consumption and seminomatous testicular cancer. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2189–95)

Cabinetmakers may be at an increased risk of testicular cancer.

BACKGROUND:In a population-based case-control study we examined the association between residential exposure to overhead high-voltage lines and testicular cancer.METHODS:We recorded the residential biography of cases with testicular cancer identified by the Hamburg Cancer Registry and of controls that were randomly selected from the mandatory registry of residents in Hamburg. The study included 145 incident cases between 15 and 69 years of age, diagnosed between 1995 and 1997, and 313 controls, matched for age in 5-year strata. In model A, exposure was defined by distance (ever vs never). Model B took into account residence time and the inverse distance from the nearest high-voltage line. It distinguished between low and high exposure, the never exposed persons serving as a reference group. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by unconditional logistic regression. For men below the age of 40 years and men aged 40 years and over separate analyses were carried out.RESULTS:Within a corridor of 100 m the prevalence of exposure to high-voltage lines in Hamburg was 6.9% in cases and 5.8% in controls (OR=1.3; 95% CI=0.56-2.80). In the more complex model B we found an OR of 1.2 (95% CI=0.60-2.47) for low exposure and 1.7 (95% CI=0.91-3.32) for high exposure. Younger men show slightly increased risks in both models.CONCLUSIONS:In all, residential exposure to high-voltage lines did not seem to be a major risk factor for testicular cancer in our study. Yet, the fact that risks for men below the age of 40 years were slightly increased in both exposure models deserves further attention.

Previous studies showed an increased prevalence of testicular cancer among fathers and brothers of testicular cancer patients. We examined whether testicular, other genital, and breast cancers aggregate in parents and siblings of testicular cancer patients in a population-based case-control study, including males, ages 15 to 69 years at diagnosis, with primary malignant tumors of the testes or extragonadal germ cell tumors. Controls were ascertained through the mandatory registries of residents and frequency matched to the cases by age and region of residence. In a face-to-face interview, 269 cases and 797 controls provided health-related information on parents and siblings. We calculated odds ratios (OR) and corresponding 95% confidence intervals (95% CI) based on the generalized estimating equations technique, adjusting for the matching variables and relatives' age. Three (1.1%) fathers and eight (3.2%) brothers of cases were affected with testicular cancer compared with four (0.5%) fathers and two (0.2%) brothers of controls. The OR (95% CI) of familial testicular cancer was 6.6 (2.35-18.77). Only nonseminoma patients had fathers with testicular cancer, whereas the affected brothers were all related to seminoma patients. Overall, we found an increased risk for genital other than testicular cancers (OR 2.5, 95% CI 1.43-4.43). For breast cancer, we detected an increased risk in sisters (OR 9.5, 95% CI 2.01-45.16, adjusted for age of study participant and age of sister) but not in mothers. Our findings support the hypothesis that testicular and other genital cancers have a common familial component that may be due to genetic and shared exogenous factors such as estrogen exposure during fetal development.

Objective: It has been estimated that alcohol drinking increases the risk of breast cancer in women by approximately 7% for each increment of 10 g alcohol per day. However, the few studies conducted on breast cancer among men have failed to detect an association with quantitative measures of alcohol drinking, even if the alcohol intake is generally higher in men than in women. On the other hand, increased risks of male breast cancer were inconsistently reported in alcoholics or patients with liver cirrhosis. We have investigated the role of alcohol drinking in male breast cancer using data collected in a population-based case–control study on seven rare cancers, conducted in Denmark, France, Germany, Italy, and Sweden.

BACKGROUND:There is some evidence of an elevated risk for testicular cancer among firefighters.METHODS:We performed a population-based case-control study including 269 testicular cancer cases and 797 controls matching on age and region with a special focus on occupational exposures. Job tasks were coded according to the International Standard Classification of Occupations (ISCO 68). We used conditional logistic regression to calculate odds ratios (OR).RESULTS:Three controls (0.4%) and four cases (1.5%) ever worked as firefighters. Firefighters showed an increased odds of testicular cancer in the matched evaluation (OR = 4.3, 95% confidence interval (95% CI) 0.7-30.5). The adjustment for a history of cryptorchidism or family history of testicular cancer did not alter our results.CONCLUSION:Although the association between firefighting and testicular cancer risk is based on only small numbers of exposed subjects in our study, the finding is consistent with a recent cohort study from New Zealand. Occupational hazards experienced by firefighters may increase the risk of testicular cancer.

Objective: Two recent studies indicated that cooks may have an increased risk of uveal melanoma. Here we report findings of two German case–control studies regarding cooking and uveal melanoma risk. Methods: We conducted a hospital and population-based case–control study of uveal melanoma and occupational exposures. We then pooled these results. Overall, 118 cases and 475 controls matching on age, sex and study regions were interviewed. We classified subjects as exposed to an occupational category (i.e. cooks) if they had ever worked within this category for at least six months or more. Subjects who had worked as cooks were rated as either (a) having prepared food without having cooked and therefore unexposed to cooking or (b) having cooked. We used conditional logistic regression models to calculate pooled odds ratios (OR) and 95% confidence intervals (95% CI). Results: Subjects who had ever cooked had an OR of 6.1 (95% CI: 1.7–22.2). Cooking was associated with an OR of 4.0 (95% CI: 0.8–20.1) for a job duration of 0.5–2 years and with an OR of 11.4 (95% CI: 1.6–81.9) for a job duration more than 2 years. Conclusions: In light of the similar finding in other studies, the association deserves further attention.

The occurrence and number of melanocytic nevi are among the most important known risk factors for the development of malignant melanoma. Studying the causes of nevi should lead to successful strategies in the prevention of melanoma. Among 11,478 white German children of preschool age the association between benign melanocytic nevi and a number of risk factors for skin cancer was examined. We found that subjects with a reported history of increased sun exposure, for example, painful sunburns, and an increased number of holidays in foreign countries with a sunny climate had significantly higher nevus counts than individuals without these characteristics. Our results provide further evidence that nevus counts may not only be part of a genetic predisposition but also a result of increased exposure to ultraviolet radiation. Together with the fact that a high nevus count is the most relevant risk factor for malignant melanoma, the results strongly indicate a connection between UV-radiation and the development of melanocytic skin cancer. In conclusion, strategies to reduce the incidence of melanoma should begin with young children.

Objectives: In a population-based case–control study, we examined the association of testicular cancer and electromagnetic fields (EMF) in the workplace. Methods: Incident cases (n = 269) were recruited between 1995 and 1997. A total of 797 controls matched on age and region were randomly selected from mandatory registries of residents. EMF exposure was assessed for five categories in standardized face-to-face interviews using closed questions. For each exposure category, odds ratios (OR) were calculated, stratified by age and region, and in a more complex model weighted by duration and distance using conditional logistic regression. Subgroup analyses were conducted for seminoma and non-seminoma and for blue- and white-collar workers. Additionally, potential radar exposure was individually assessed by experts based on all available information including free text. Results: There was no excess risk for cases who reported to have ever worked near the following: radar units (OR = 1.0; 95% CI = 0.60–1.75); radiofrequency emitters (OR = 0.9; 95% CI = 0.60–1.24); electrical machines (OR = 1.0; 95% CI = 0.72–1.33); high-voltage lines or high-voltage electrical transmission installations (OR & equals; 0.7; 95% CI = 0.38–1.18); or visual display units or complex electrical environments (OR = 0.9; 95% CI = 0.67–1.21). The results for the weighted exposure and subgroup analyses did not differ substantially. For radar exposure as assessed by the experts, the OR was 0.4 (95% CI = 0.13–1.16). Conclusions: EMF exposure in the workplace does not seem to be a relevant risk factor for testicular cancer in our study.

BACKGROUND:The strength of the association between undescended testis and testicular cancer varies considerably across studies. Here we report the effect of various classifications of self-reported history of undescended testis and different data sources on the estimates of the risk of testicular cancer from a case-control study.METHODS:We performed a population-based case-control study including 269 testicular cancer cases and 797 controls matched on age and region. Medical history was assessed by interviews (index persons) and mailed questionnaires (mothers). We used conditional logistic regression to calculate odds ratios (OR) and kappa coefficients to assess agreement between different sources of information.RESULTS:Odds ratios for testicular cancer ranged between 2.4 and 5.4 based on the sons' self-reports and between 1.1 and 1.9 based on the mothers' reports. The agreement between the sons and mothers on undescended, gliding or retractile testis was fair (kappa 0.53) and was good when these conditions were treated by surgery (kappa 0.89). The rating of a history of undescended testis by two urologists was fair (kappa 0.54).CONCLUSIONS:The questionnaire design, the classifications of undescended testis and data sources have an important impact on the OR for the association of undescended testis and testicular cancer. These factors may partially explain the heterogeneity of the OR for this association in case-control studies relying on self-reports.

STUDY OBJECTIVE:The prevalence of gallstone disease, time trends in the frequency of cholecystectomies and risk factors for the occurrence of cholelithiasis were examined in a cross-sectional population study.METHODS:The survey was based on a random sample from the populations of 4 regions in Germany, stratified by region, age and sex. Information on the frequency of gallstone disease and on potential risk factors were collected by standardized interviews. For the statistical analysis, multiple logistic regression was used.RESULTS:Overall, 1,085 persons were interviewed. The age-standardized prevalence of known gallstones was 4.2% for men and 14.5% for women. The frequency of cholecystectomy almost tripled in women from 1985 to 1994 as compared to 1975 to 1984 despite a decreasing trend in gallstone diagnoses in the same time period. No such trend was apparent in men. In men, age, body weight, changes in body weight, diabetes and use of corticosteroids were identified as risk factors for gallstone disease. In women, gallstone disease was also associated with body weight, changes in body weight and age, and, in addition, the number of births. An inverse association with gallstone disease was found for use of oral contraceptives and level of education in women.

BACKGROUND:A federal law effective in 1995 makes it mandatory for all German States to build up population-based cancer registries. Although the law provides a model of cancer registration, each State may modify this by State-specific regulations, as long as they ensure data exchange between the registries and between registries and scientific institutions. The 'Network of German Population-Based Cancer Registries' constitutes the basis for cooperation among the German cancer registries. In order to improve the cooperation between physicians and epidemiologists, and to demonstrate the benefits of cancer registration, the network published a booklet containing facts on time-trends in cancer incidence during the last two decades.METHODS:Information on cancer incidence and mortality was derived from the population-based cancer registries of Saarland, the former German Democratic Republic (until 1989), the City of Hamburg and the region of Münster. Altogether these registries cover a population of about 23 million. Sixteen types of cancer were selected for the analyses.RESULTS:Major increases in cancer incidence were observed for female lung cancer, testicular cancer, cancer of the oral cavity, malignant melanoma of the skin and non-Hodgkin's lymphoma. Incidence rates also increased for cancer of the female breast, prostate cancer and colorectal cancer. A decrease was observed for stomach and cervical cancer.DISCUSSION:In 1998, only a small fraction of all German adults were monitored by a population-based cancer registry, making it impossible to work out accurate incidence rates for the whole of Germany. Several new cancer registries have been built up recently. Data summaries of existing German population-based cancer registries assist in enhancing the completeness of new cancer registries.

PURPOSE:The rate of testicular cancer is increasing. Trauma severe enough to cause testicular atrophy is a putative risk factor for testicular cancer but the epidemiological evidence is not conclusive. A population based, multicenter case-control study was performed from 1995 to 1997 to investigate potential risk factors for gonadal and extragonadal germ cell cancer.MATERIALS AND METHODS:The study was done in 5 German regions. Interviews were performed with 269 eligible male patients with a histologically verified diagnosis and 797 controls. Detailed information on medical and family history was collected at personal interviews.RESULTS:We identified a significantly elevated risk for testicular cancer in relation to testis and/or groin trauma (odds ratio 2.5, 95% confidence interval [CI] 1.51 to 4.20). After introducing a lag time by excluding reports of trauma within the last 12 months before diagnosis or interview the corresponding odds ratio was 2.1 (95% CI 1.24 to 3.61). Analysis of the circumstances and the reported types of injury allowed us to restrict the study to testis trauma specifically, which had an odds ratio of 3.49 (95% CI 1.78 to 6.81). To account for a potential reporting bias analysis was restricted to traumatic episodes for which medical attention was sought. This restriction resulted in an odds ratio of 0.70 (95% CI 0.19 to 2.63) after excluding from study trauma reports within the last 12 months.CONCLUSIONS:The results of our study do not support the hypothesis that testicular trauma is an important risk factor for testicular cancer. The possibility of recall bias should be considered.

Study Objective: The prevalence of gallstone disease, time trends in the frequency of cholecystectomies and risk factors for the occurrence of cholelithiasis were examined in a cross-sectional population study. Methods: The survey was based on a random sample from the populations of 4 regions in Germany, stratified by region, age and sex, information on the frequency of gallstone disease and on potential risk factors were collected by standardized interviews. For the statistical analysis, multiple logistic regression was used. Results: Overall, 1,085 persons were interviewed. The age-standardized prevalence of known gallstones was 4.2% for men and 14.5% for women. The frequency of cholecystectomy almost tripled in women from 1985 to 1994 as compared to 1975 to 198ri despite a decreasing trend in gallstone diagnoses in the same time period. No such trend was apparent in men. In men, age, body weight, changes in body weight, diabetes and use of corticosteroids were identified as risk factors for gallstone disease. ln women, gallstone disease was also associated with body weight, changes in body weight and age, and in addition, the number of births. An inverse association with gallstone disease was found for use of oral contraceptives and level ofeducationln women.

Zusammenfassung Studienziel: Prävalenz des Gallensteinleidens, zeitliche Trends in der Häufigkeit von Cholezystektomien und Risikofaktoren für die Entwicklung von Gallensteinen wurden in einer bevölkerungsbezogenen Studie in vier deutschen Regionen erfasst. Methoden: Als Studienpopulation diente eine nach Region, Alter und Geschlecht stratifizierte Zufallsstichprobe aus den Bevölkerungen von Hamburg, Bremen, Essen und dem Saarland, die als Kontrollgruppe für eine multizentrische Fallkontrollstudie zwischen 1995 und 1997 durch standardisierte Interviews befragt wurde. Die statistische Analyse erfolgte mittels multipler logistischer Regression. Ergebnisse: Ingesamt wurden 1 085 Personen befragt. Die altersstandardisierte Gallensteinprävalenz für die 35– bis 69-Jährigen betrug 4,2% bei den Männern und 14,5% bei den Frauen. Die Häufigkeit der Cholezystektomien hat sich bei den Frauen im Zeitraum von 1985 bis 1994 verdreifacht im Vergleich zu 1975 bis 1984, trotz einer abnehmenden Tendenz bei den Gallensteindiagnosen im gleichen Zeitraum. Bei den Männern war dieser Trend nicht zu beobachten. Als Risikofaktoren für das Auftreten von Gallensteinen wurden für Männer höheres Alter, Körpergewicht und Gewichtsschwankungen, Diabetes mellitus und Corticoideinnahme identifiziert. Bei den Frauen zeigten sich eine ansteigende Häufigkeit mit der Anzahl der Geburten und mit Gewicht, Gewichtsschwankungen und Alter sowie eine negative Assoziation mit dem Ausbildungsstand und der Einnahme oraler Kontrazeptiva.

BACKGROUND:A German Federal law enacted in 1995 aims at nation-wide cancer registration, the details of realization based on local regulations being left to the individual Federal states. The impact of different approaches and regulations on the results of registration was investigated at three well-established records in the Saarland, Hamburg and North-Rhine Westphalia, taking the group of lymphoma and leukaemia (ICD 200-208) taken as an example.MATERIAL AND METHODS:Incidence and mortality rates calculated by the record files for the period from 1987 to 1994 were compared. The resulting mortality/incidence ratios were compared as well as the percentage of cases in each register with death certificates (DCO) as the only information source.RESULTS:There was a distinct increase of incidence rates visible in Hamburg and Münster. As far as the male patients was concerned, both records attained the level of Saarland at the end of the period. However, the leukaemia and lymphoma mortality figures for males and females was about 10% lower for Saarland than in the comparative regions. The male mortality incidence ratio was 0.55 for Saarland versus 0.60 average in Hamburg and Münster at the end of the period. In Saarland and Hamburg there was a decrease of DCO-cases from 14% to less than 6% in 1994. More constant values around 11% could be observed in the Münster registry. The distribution of diagnosis within the group as well as age-specific incidence rates for the selected diagnosis "lymphatic leukaemia" (ICD 204) and "Hodgkin's disease" (ICD 201) yielded only slight differences.CONCLUSION:The increase of incidence rates in Münster and Hamburg indicates more complete reporting. Assuming that the survival rates are the same in the three regions, the lower mortality in Saarland points to lower morbidity. Hence in spite of a definite approximation the cancer registries in Hamburg and Münster do not reach the level of completeness of the Saarland cancer registry. This may be due to the informed patient consent required by regional law for reports to the registry. To achieve completeness a special reporting procedure for pathological and haematological Institutes is mandatory. Simple indicators should be available in each registry for continuous estimation of completeness. Standardised case definitions and rules for the coding of diagnosis in cancer registries will improve national and international comparability and feasibility of data exchange.