Risk of testicular cancer in subfertile men: case-control study

ObjectiveTo evaluate the association between subfertility in men and the subsequent risk of testicular cancer.DesignPopulation based case-control study.SettingThe Danish population.ParticipantsCases were identified in the Danish Cancer Registry; controls were randomly selected from the Danish population with the computerised Danish Central Population Register. Men were interviewed by telephone; 514 men with cancer and 720 controls participated.ResultsA reduced risk of testicular cancer was associated with paternity (relative risk 0.63; 95% confidence interval 0.47 to 0.85). In men who before the diagnosis of testicular cancer had a lower number of children than expected on the basis of their age, the relative risk was 1.98 (1.43 to 2.75). There was no corresponding protective effect associated with a higher number of children than expected. The associations were similar for seminoma and non-seminoma and were not influenced by adjustment for potential confounding factors.ConclusionThese data are consistent with the hypothesis that male subfertility and testicular cancer share important aetiological factors.

Key messages

• The incidence of testicular cancer has increased in the past 50 years, and there is some evidence to suggest that sperm quality has decreased in the same period
• It has been hypothesised that common aetiological factors may exist for testicular cancer and for male subfertility
• The association between male subfertility and subsequent risk of testicular cancer is strong and consistent with the hypothesis of a common aetiology
• The association is similar for seminoma and non-seminoma, and it persists when several potentially confounding factors are taken into account

     

Risk of testicular cancer after vasectomy: cohort study of over 73,000 men.

OBJECTIVE--To confirm or refute reports that vasectomy may increase the risk of cancers of the testis and prostate. DESIGN--Computerised record linkage study of cohort of men with vasectomy and comparison of cancer rates with those in the whole Danish population; manual check of all records of patients with testicular and prostate cancer diagnosed within the first year of follow up. SETTING--Denmark 1977-89. SUBJECTS--Cohort of 73,917 men identified in hospital discharge and pathology registers as having had a vasectomy for any reason during 1977-89. MAIN OUTCOME MEASURES--Observed incidences of testicular, prostate, and other cancers up to the end of 1989. RESULTS--The overall pattern of cancer incidence in the study cohort was similar to that expected nationally. No increased incidence in testicular cancer was observed (70 cases; standardised morbidity ratio 1.01 (95% confidence interval 0.79 to 1.28)). The incidence during the first year of follow up was also close to that expected (nine cases; standardised morbidity ratio 0.80 (0.36 to 1.51)). The incidence of prostate cancer was not increased (165 cases; standardised morbidity ratio 0.98 (0.84 to 1.14)). CONCLUSIONS--The incidence of testicular cancer in men with vasectomy is no higher than in other men. Vasectomy does not cause testicular cancer and does not accelerate the growth or diagnosis of pre-existing testicular neoplasms. Data concerning a causal relation between vasectomy and prostate cancer were inconclusive.     

Prevalence of carcinoma in situ of the testis in 207 oligozoospermic men from infertile couples: prospective study of testicular biopsies.

OBJECTIVE: To investigate the prevalence of carcinoma in situ of the testis in a group of oligozoospermic men from infertile couples. DESIGN: A consecutive group of oligozoospermic men from infertile couples were offered bilateral testicular biopsy. The observed prevalence of carcinoma in situ was compared with the expected prevalence of testicular cancer in a corresponding age matched population of Danish men, assuming all untreated cases of carcinoma in situ progress to tumour stage. This calculation was based on data from the Danish Cancer Registry. SUBJECTS: 207 men aged 18-50 years who had sperm density below 10 million/ml in two samples within the previous 2 years or sperm density below 20 million/ml in two samples within the previous 2 years and a history of cryptorchidism or one or two atrophic testicles (orchidometer volume less than 15 cm3), or both. INTERVENTIONS: Bilateral testicular biopsies. MAIN OUTCOME MEASURES: Carcinoma in situ in the biopsy specimen. RESULTS: No case of carcinoma in situ was found among the 207 men. The expected number in a normal age matched population of corresponding size was 0.8. CONCLUSIONS: There is no increase in risk of carcinoma in situ of the testis in moderately oligozoospermic men of couples referred because of infertility.     

Similarities in the Age-Specific Incidence of Colon and Testicular Cancers

Colon cancers are thought to be an inevitable result of aging, while testicular cancers are thought to develop in only a small fraction of men, beginning in utero. These models of carcinogenesis are, in part, based upon age-specific incidence data. The specific incidence for colon cancer appears to monotonically increase with age, while that of testicular cancer increases to a maximum value at about 35 years of age, then declines to nearly zero by the age of 80. We hypothesized that the age-specific incidence for these two cancers is similar; the apparent difference is caused by a longer development time for colon cancer and the lack of age-specific incidence data for people over 84 years of age. Here we show that a single distribution can describe the age-specific incidence of both colon carcinoma and testicular cancer. Furthermore, this distribution predicts that the specific incidence of colon cancer should reach a maximum at about age 90 and then decrease. Data on the incidence of colon carcinoma for women aged 85–99, acquired from SEER and the US Census, is consistent with this prediction. We conclude that the age specific data for testicular cancers and colon cancers is similar, suggesting that the underlying process leading to the development of these two forms of cancer may be similar.     

Trends in the incidence of testicular germ cell cancer in Ontario by histologic subgroup, 1964-1996

BACKGROUND: Testicular cancer is rare but is notable because it affects mainly young men. The incidence of this disease has been increasing in developed countries throughout the world for several decades. The authors examined trends in the incidence of testicular germ cell cancer in Ontario for the period 1964-1996 according to the 2 main histologic groups, seminoma and non-seminoma. METHODS: Data on incident cases of testicular germ cell cancer diagnosed in Ontario residents aged 15-59 years between 1964 and 1996 were extracted from the population-based Ontario Cancer Registry. Annual rates of testicular cancer for the 2 histologic groups were analysed by means of log-linear regression to estimate average annual percent change. RESULTS: Between 1964 and 1996 the incidence of testicular germ cell cancer increased by 59.4%, from 4.01 to 6.39 per 100,000. This corresponded to an average annual increase of about 2% for both nonseminoma and seminoma. The relative increase in incidence was greatest in the lowest age group (15-29 years) for both histologic groups, although the data suggest that the incidence of nonseminoma cancer in this age group began to decline in the early 1990s. The increase in incidence appears to be due to a birth cohort effect, with more recent cohorts of men at increased risk. INTERPRETATION: The rise in the incidence of testicular germ cell cancer, not only in Ontario but also in many developed countries, requires investigation. The search for explanatory factors should focus on exposures whose prevalence may have increased over the past few decades and that are common enough to affect population incidence. The similarity of trends for seminoma and nonseminoma cancer suggests that the underlying risk factors are likely the same.     

Time trends in testicular cancer in Croatia 1983-2007: rapid increases in incidence, no declines in mortality

Testicular cancer, although a rare malignancy, represents the most common cancer in young male populations of Western origin. While increasing incidence trends of testicular cancer have been reported, mortality is declining in many high-resource settings. Using national data from the Croatian National Cancer Registry for the period 1983-2007, time trends were analysed by joinpoint regression and Age-Period-Cohort models. The present study is the first to analyse the testicular cancer trends in the Croatian population. Over the 25-year period, a mean number of 89 incident cases and 13 deaths were reported annually. The observed mean annual increases in age-standardised rates were 7.0% for incidence and 1.6% for mortality, with no abrupt linear changes (joinpoints) identified. The incidence rates of testicular cancer incidence have been steeply increasing in successive cohorts born since the mid-1930s. The rapid rise in testicular cancer incidence in the Croatian population appears to be one of the highest rates of increase recorded in Europe and worldwide. The lack of decline in the mortality rates over time, while based on relatively few deaths, highlights a need for improvements in diagnostics and management of therapy in Croatia in order to improve the survival and quality-of-life of testicular cancer patients.     

Cancer incidence among Danish Seventh-day Adventists and Baptists

IntroductionAmerican Seventh-day Adventists have been reported to have lower cancer mortality and incidence than the general population. Adventists do not consume tobacco, alcohol or pork, and many adhere to a lacto-ovo-vegetarian lifestyle. Baptists discourage excessive use of alcohol and tobacco. In this study, we investigated whether the incidence of cancer in a large cohort of Danish Adventists and Baptists was different compared to the general Danish population.Material and methodsWe followed 11,580 Danish Adventists and Baptists in the nationwide Danish Cancer Registry, which contains information on cases of cancer for 1943–2008. Cancer incidence in the cohort was compared with that in the general Danish population as standardized incidence ratios (SIRs) with 95% confidence intervals (CIs), and within-cohort comparisons were made with a Cox model.ResultsLower cancer incidences were observed for both Seventh-day Adventist men (SIR, 66; 95% CI, 60–72) and women (85; 80–91). The same result was observed for Baptists although not as low. The differences were most pronounced for smoking-related cancers such as those of the buccal cavity and lung (SIR, 20; 13–30 for Seventh-day Adventist men and 33; 22–49 for Seventh-day Adventist women). The incidences of other lifestyle-related cancers, such as of stomach, rectum, liver and cervix, were also decreased. In general, the SIRs were lower for men than for women, and Adventists had lower hazard rates than Baptists.DiscussionOur findings point to the benefits of compliance with public health recommendations and indicate that lifestyle changes in the population might change the cancer risks of individuals.     

Space-Time Analysis of Testicular Cancer Clusters Using Residential Histories: A Case-Control Study in Denmark

Though the etiology is largely unknown, testicular cancer incidence has seen recent significant increases in northern Europe and throughout many Western regions. The most common cancer in males under age 40, age period cohort models have posited exposures in the in utero environment or in early childhood as possible causes of increased risk of testicular cancer. Some of these factors may be tied to geography through being associated with behavioral, cultural, sociodemographic or built environment characteristics. If so, this could result in detectable geographic clusters of cases that could lead to hypotheses regarding environmental targets for intervention. Given a latency period between exposure to an environmental carcinogen and testicular cancer diagnosis, mobility histories are beneficial for spatial cluster analyses. Nearest-neighbor based Q-statistics allow for the incorporation of changes in residency in spatial disease cluster detection. Using these methods, a space-time cluster analysis was conducted on a population-wide case-control population selected from the Danish Cancer Registry with mobility histories since 1971 extracted from the Danish Civil Registration System. Cases (N=3297) were diagnosed between 1991 and 2003, and two sets of controls (N=3297 for each set) matched on sex and date of birth were included in the study. We also examined spatial patterns in maternal residential history for those cases and controls born in 1971 or later (N= 589 case-control pairs). Several small clusters were detected when aligning individuals by year prior to diagnosis, age at diagnosis and calendar year of diagnosis. However, the largest of these clusters contained only 2 statistically significant individuals at their center, and were not replicated in SaTScan spatial-only analyses which are less susceptible to multiple testing bias. We found little evidence of local clusters in residential histories of testicular cancer cases in this Danish population.     

Cancer risk and all-cause mortality among Norwegian military United Nations peacekeepers deployed to Kosovo between 1999 and 2011

ObjectiveMedia reports of leukaemia and other cancers among European United Nations (UN) peacekeepers who served in the Balkans, and a scientific finding of excess Hodgkin lymphoma among Italian UN peacekeepers who served in Bosnia, suggested a link between cancer incidence and depleted uranium (DU) exposure. This spurred several studies on cancer risk among UN peacekeepers who served in the Balkans. Although these studies turned out to be negative, the debate about possible cancers and other health risks caused by DU exposure continues. The aim of the present study was to investigate cancer incidence and all-cause mortality in a cohort of 6076 (4.4% women) Norwegian military UN peacekeepers deployed to Kosovo between 1999 and 2011.MethodsThe cohort was followed for cancer incidence and mortality from 1999 to 2011. Standardised incidence ratios for cancer (SIR) and mortality ratios (SMR) were calculated from national rates.ResultsSixty-nine cancer cases and 38 deaths were observed during follow-up. Cancer incidence in the cohort was similar to that in the general Norwegian population. No cancers in the overall cohort significantly exceeded incidence rates in the general Norwegian population, but there was an elevated SIR for melanoma of skin in men of 1.90 (95% confidence interval [CI] 0.95–3.40). A fivefold increased incidence of bladder cancer was observed among men who served in Kosovo for ≥1 year, based on 2 excess cases (SIR = 5.27; 95% CI 1.09–15.4). All-cause mortality was half the expected rate (SMR = 0.49; 95% CI 0.35–0.67).ConclusionOur study did not support the suggestion that UN peacekeeping service in Kosovo is associated with increased cancer risk.     

A reanalysis of liver cancer incidence in Danish patients administered thorotrast using a two-mutation carcinogenesis model

In recent years, a two-mutation carcinogenesis (TMC) model has been used to analyze epidemiological data and estimate the radiation risks at low doses for the organs affected. Here the TMC model was used to reanalyze the liver cancer incidence in the Danish population in general and in patients administered Thorotrast, and to estimate the radiation risks for the liver. The data for 807 patients for whom sufficient data on the injected volumes of Thorotrast were available were used in this reanalysis. These data were combined with data on liver cancer incidence in the Danish population as the baseline or background incidence. Because males and females show different baseline liver cancer incidences, separate fits were made for males and females. The fits showed that the radiation effect could be ascribed entirely to the radiation dependence of the first mutation rate of the TMC model, which was higher for females than for males. The second mutation rate was not significantly dependent on dose. The radiation risks for the liver were calculated on the basis of the model parameters. These risks for lifetime exposures are about the same for males and females and are between a factor of 2 and 10 higher than current estimates. The discrepancy between the model results and previous risk estimates probably arises because the model calculations give more complete lifetime radiation risk estimates. For short-term exposures of the liver to ionizing radiation, the maximum radiation-induced excess liver cancer risk per unit dose applies to exposures at the age of about 10; exposures at ages above 35 have a radiation effect of less than approximately 15% of this maximum.     

Trends in incidence and survival from anal cancer and incidence of high-grade anal intraepithelial neoplasia in Denmark

ObjectiveThe aim of the current study was to assess temporal trends in incidence of anal squamous cell carcinomas (SCC) and high-grade anal intraepithelial lesions (AIN2/3), and estimate survival from anal cancer and factors related to 5-year mortality in Denmark.MethodsWe analyzed anal SCC and AIN2/3 cases in the period of 1998–2018 from the Danish Cancer Register and the Danish Registry of Pathology, respectively. Overall, period, gender, and histology specific age-standardized incidence rates, average annual percentage change (AAPC), and 5-year relative survival were estimated. Cox proportional hazards models were applied to evaluate the effect on 5-year mortality of period, age, gender, and stage of disease.ResultsAltogether 2580 anal cancers and 871 AIN2/3 were identified. The AIN2/3 incidence increased for women 1998–2007 (AAPC: 3.5% (95% CI −0.7, 8.0)) and then tended to decrease during 2008–2018(AAPC: −5.2% (95% CI −9.6, −0.6)). A similar pattern was observed for men, although at a lower incidence with the decrease starting later (2008–2012) and the trend not reaching statistical significance. The anal SCC incidence increased over the whole study period for both women and men (women AAPC: 4.0% (95% CI 3.2%, 4.9%) and men AAPC: 3.6% (95% CI 2.3%, 4.9%)). The relative survival improved over time (from 61% to 72%). Being older and male was associated with a higher risk of dying within 5 years.ConclusionsThere is a need to focus attention on anal cancer and its precursor lesions, as the cancer incidence continues to increase. Actions could include screening and gender-neutral HPV vaccination.     

Occupational exposure to solar ultraviolet B radiation and risk of prostate cancer in Danish men

ObjectivesFormer epidemiological studies have indicated that solar ultraviolet B radiation (UV) may reduce the risk of prostate cancer, however, the evidence is inconclusive. To contribute with evidence, the present study aimed to evaluate the association between occupational UV exposure and prostate cancer in Danish men.MethodsA total of 12,268 men diagnosed with primary prostate cancer before age 70 were identified via the Danish Cancer Registry. The Danish Civil Registration System was used to randomly select five male controls matched on year of birth, alive and free of prostate cancer at the time of diagnosis of the index case. Full individual-level employment history was retrieved from the Danish Supplementary Pension Fund Register and linked to a job exposure matrix to assess occupational UV exposure. Conditional logistic regression was used to estimate odds ratios (ORs) with corresponding 95 % confidence intervals.ResultsWe observed an inverse association between ever exposure to occupational UV and prostate cancer (OR=0.93, 95 % CI: 0.89–0.97). Longer duration of exposure (≥20 years: OR=0.90, 95 % CI: 0.84–0.96) and highest cumulative exposure (OR=0.90, 95 % CI: 0.84–0.96) were both inversely associated with disease risk.ConclusionsThe present study indicates a modest protective effect from occupational UV exposure on the risk of prostate cancer. This finding needs further attention in future large-scale studies.     

Incorporation of inter-individual heterogeneity into the multistage carcinogenesis model: approach to the analysis of cancer incidence data

We investigate a multistage carcinogenesis frailty model to incorporate inter-individual heterogeneity into carcinogenic response. Attention is focused on inference concerning the effects of different sources of population heterogeneity on cancer rates. The authors consider unobserved variability arising from either carcinogen exposure or background characteristics. Gamma and Inverse-Gaussian distributions are selected for frailty models, and the baseline hazard function is the generalized Armitage-Doll model (i.e. non-frailty model) in which exposure effects shift the age scale instead of acting multiplicatively on cancer rates. For illustration, we apply the method to solid cancer data from a cohort of atomic bomb survivors to examine some features of proposed models. The results show that the Gamma frailty model for the heterogeneity of baseline rates provides the best goodness-of-fit of the model and a non-zero frailty variance. Parameter estimates are, for the most part, comparable between the Gamma and Inverse-Gaussian frailty models. In a heterogeneous population the exposure effects on young adulthood cancer rates might be underestimated for the non-frailty model. Meaningful information regarding each source of heterogeneity has been provided by the proposed method. Therefore, the multistage carcinogenesis frailty model approach is useful for analyses of epidemiological cancer data to assess population heterogeneity and heterogeneity-influenced exposure effects.     

Augmentation de l’incidence du cancer du testicule: état de la question

Although germ cell cancer is rare (about 1% of cancers in male), it is the commonest cancer in young man. Many studies in Europe, Northern America and Australia show that incidence rates of testis cancer are climbing. In Northern Europe and America, where cancer registration exist since the fifties, it is showed that overall age-adjusted incidence rate of testis cancer has increased more than 3 fold during the past 50 years. This increase affect particularly teenagers and young men. The increase of incidence rates is less documented in under developed countries but recent studies seem to confirm an increase of incidence rates in many parts of the world, even if testis cancer remain rarer in non Caucasian populations. Etiologies of a such increase are still unknown, but arguments point in view a possible relation between environmental hormone disrupters and many hormonodependent cancers, such as testicular neoplasm, the cancer of the breast or even prostate cancer. Epidemiological studies with large sample size are needed to identify risk factors responsible for the increase of incidence rates of testis cancer.     

Socio-economic inequalities in testicular cancer survival within two clinical studies

Background: Testicular cancer is the most common cancer in men under 35 years of age, and has the highest survival for adult male malignancies. Despite the fact that survival is very high, there is evidence that survival differs between socio-economic groups. Methods: We analysed survival patterns for 1606 testicular cancer patients diagnosed during 1984–2001 and recruited to one of two clinical studies. The first was a surveillance study to determine relapse-free survival after orchidectomy in 865 patients with stage I nonseminomatous germ-cell testicular cancer diagnosed during 1984–1991 (TE04). The second study was a trial in which 1174 men with stage I seminomatous germ-cell tumours were randomised to receive radiotherapy or one injection of carboplatin between 1996 and 2001 (TE19). The number of men available for analysis from these two studies was 578 and 1028, respectively. We followed these patients up for their vital status, and assigned them an ecological measure of deprivation. Crude and relative survival were estimated at 5 and 10 years by socio-economic deprivation. Results: No significant socio-economic gradient was seen: 1.3% (95% CI ?0.3% to 3.1%) at 5 years and 2.1% (95% CI ?0.5% to 4.7%) at 10 years. Conclusion: We conclude that, given equal treatment at a given stage of disease, survival from testicular cancer does not depend on socio-economic status. This suggests that the socio-economic gradient in testicular cancer survival in the general population is more likely to be attributable to health care system factors than to personal or socio-economic factors in the men themselves.     

The incidence of male genital tumors: a cellular model for the age dependence.

Most human tumors, including most male genital tumors, exhibit an exponential increase in incidence with advancing age of the host. This exponential age-incidence pattern can be explained by the accumulation of mutations in the stem cells of the tissues of tumor origin. The age-incidence pattern for testicular tumors, however, is unique with a large linear increase in incidence from age 14 to 30 and a linear decline in incidence from age 30 to 60. After age 60, the incidence of testicular tumors remains low and constant. The probability of testicular tumorigenesis is determined by the susceptibility of male germ cells to neoplastic mutation and/or the neoplastic mutagenicity of the male germ cell environment. Since there is no evidence for an environmental mutagen which is specific for male germ cells, and since male germ cells are unusually susceptible to mutation, we interpret the variation in testicular tumor incidence with age as a reflection of the susceptibility of male germ cells to neoplastic mutation. Cell are most susceptible to mutation during genome replication and we propose a model for testicular tumorigenesis which is consistent with the available data on male germ cell proliferation and with the data on testicular tumor incidence.     

Facteurs de risques environnementaux et/ou professionnels du cancer du testicule

Despite a low overall incidence (1% of all malignant neoplasms), testicular cancer is the most common malignancy among young men. Over the last 40 years, this incidence rate has substantially risen in most industrialised countries. However, the aetiology of testicular cancer remains largely unknown. Only cryptorchidism, and to a lesser extent a family history of testicular cancer, may be considered to be well established risk factors. Numerous attempts have been made to assess the potential role of occupational exposures in adult life as a risk factor for TC, but no clear hypotheses have yet emerged from previous studies in this field. A major limitation of all occupational studies is that no single toxic substance has been clearly identified, and consequently the significant association observed between some job titles and risk of testicular cancer must be interpreted very carefully. In this respect, comparative occupational studies of exposed and non-exposed workers including rigorous and valid job-matrix exposure assessment are needed to study potential relationships between certain occupational exposures and testicular cancer.     

Fetal radiation exposure induces testicular cancer in genetically susceptible mice

The prevalence of testicular germ cell tumors (TGCT), a common solid tissue malignancy in young men, has been annually increasing at an alarming rate of 3%. Since the majority of testicular cancers are derived from germ cells at the stage of transformation of primordial germ cell (PGC) into gonocytes, the increase has been attributed to maternal/fetal exposures to environmental factors. We examined the effects of an estrogen (diethylstilbestrol, DES), an antiandrogen (flutamide), or radiation on the incidence of testicular germ cell tumors in genetically predisposed 129.MOLF-L1 (L1) congenic mice by exposing them to these agents on days 10.5 and 11.5 of pregnancy. Neither flutamide nor DES produced noticeable increases in testis cancer incidence at 4 weeks of age. In contrast, two doses of 0.8-Gy radiation increased the incidence of TGCT from 45% to 100% in the offspring. The percentage of mice with bilateral tumors, weights of testes with TGCT, and the percentage of tumors that were clearly teratomas were higher in the irradiated mice than in controls, indicating that irradiation induced more aggressive tumors and/or more foci of initiation sites in each testis. This radiation dose did not disrupt spermatogenesis, which was qualitatively normal in tumor-free testes although they were reduced in size. This is the first proof of induction of testicular cancer by an environmental agent and suggests that the male fetus of women exposed to radiation at about 5-6 weeks of pregnancy might have an increased risk of developing testicular cancer. Furthermore, it provides a novel tool for studying the molecular and cellular events of testicular cancer pathogenesis.     

Selecting factors predictive of heterogeneity in multivariate event time data

In multivariate survival analysis, investigators are often interested in testing for heterogeneity among clusters, both overall and within specific classes. We represent different hypotheses about the heterogeneity structure using a sequence of gamma frailty models, ranging from a null model with no random effects to a full model having random effects for each class. Following a Bayesian approach, we define prior distributions for the frailty variances consisting of mixtures of point masses at zero and inverse-gamma densities. Since frailties with zero variance effectively drop out of the model, this prior allocates probability to each model in the sequence, including the overall null hypothesis of homogeneity. Using a counting process formulation, the conditional posterior distributions of the frailties and proportional hazards regression coefficients have simple forms. Posterior computation proceeds via a data augmentation Gibbs sampling algorithm, a single run of which can be used to obtain model-averaged estimates of the population parameters and posterior model probabilities for testing hypotheses about the heterogeneity structure. The methods are illustrated using data from a lung cancer trial.     

A novel approach to estimate the German-wide incidence of testicular cancer

Background: Currently, only 7 out of 16 Federal States of Germany provide testicular cancer incidence rates with an estimated completeness of at least 90% which complicates the regional comparison of incidence rates. The aim of this study was to provide a novel approach to estimate the testicular cancer incidence in Germany by using nationwide hospitalization data. Methods: We used the nationwide hospitalization data (DRG statistics) of the years 2005–2006 including 16,6 million hospitalizations among men. We identified incident testicular cancer cases by the combination of a diagnosis of testicular cancer and an orchiectomy during the same hospitalization and estimated the age-specific and age-standardized (World Standard Population) incidence of testicular cancer across Federal States. We also analyzed available cancer registry data from 2005 to 2006. Results: A total of 8544 hospitalizations indicated incident testicular cancer cases in 2005–2006. The nationwide crude incidence rate of testicular cancer was 10,6 per 100.000 person-years. The ratio of the number of registered cases (cancer registry) to the estimated number of cases based on the hospitalization statistics ranged between 79% and 100%. There was only little variation of the age-standardized DRG-based incidence estimates across Federal States (range: 8,2–10,6 per 100.000 person-years). Discussion: We provided testicular cancer incidence estimates for each of the 16 Federal States of Germany based on hospitalization data for the first time. The low within-population incidence variability in Germany and high between-population incidence variability in Europe may indicate that ecologic factors play a causal role in the European variation of testicular cancer.