Trends in testicular germ cell tumours by ethnic group in the United States

Cytological spectrum of testicular malignancies with histopathological correlation: A retrospective analysis

BACKGROUND

Testicular malignancy is the most common solid organ cancer occurring in young men. The most common testicular malignancy is germ cell tumor. Extragonadal malignancies such as lymphomas are rare. Testicular fine-needle aspiration cytology (FNAC) in cancer is a bit controversial amidst fear of tumor seeding along the needle tract. Nevertheless, its largely safe, cost-effective technique providing a quick and fairly reliable diagnosis.

METHODS

A retrospective analysis of testicular malignancies on FNAC over a period of 9 years with cyto-histological correlation wherever possible was carried out. FNAC slides and cell blocks with immunocytochemistry wherever done were retrieved.

RESULTS

A total of 74 cases were obtained. The age ranged from 1 year to 65 years. Infiltration by leukemia was the most common malignancy detected in pediatric population, while germ cell tumors were common amongst young adults and middle-aged men. In elderly, metastatic carcinoma, infiltration by lymphoma were identified. On FNAC, 38 cases were of leukemic infiltration, 27 of germ cell tumors (subtyped as mixed germ cell tumors-15 cases, seminoma-11 cases, and yolk sac tumor-1 case) with two cases each of non-Hodgkin lymphoma, Leydig cell tumor, metastatic adenocarcinoma, and one case each of metastatic small cell carcinoma, rhabdomyosarcoma, and malignant neoplasm. Histological correlation was available in 15/74 cases. Only 3 cases were discordant. Seeding of tumor along the needle tract was not seen.

CONCLUSION

The current study deciphers the cytological spectrum of testicular malignancies on FNAC and highlights its importance as a reliable modality for a prompt diagnosis of testicular tumors guiding patient management.

Increase and Plateauing of Testicular Cancer Incidence in Austria-A Time Trend Analysis of the Past Four Decades

Background

Testicular germ cell tumors (TGCTs) are the most common malignant tumors in young men. Despite considerable geographic, ethnic, and temporal variations in the incidence of TGCTs, without convincing explanation, incidence rates of TGCTs have been increasing in many countries since, at least, the mid-20th century.

Objective

To investigate the incidence rates of TGCTs in Austria by analyzing data from the Austrian Cancer Registry.

Design setting and participants

Available data between 1983 and 2018 were provided by the Austrian National Cancer Registry and analyzed retrospectively.

Outcome measurements and statistical analysis

Germ cell tumors derived from germ cell neoplasia in situ were classified into seminomas and nonseminomas. Age-specific incidence rates and age-standardized rates were calculated. Annual percent changes (APCs) and average annual percent changes in incidence rates were determined to describe trends from 1983 to 2018. All statistical analyses were performed using SAS version 9.4 and joinpoint.

Results and limitations

The study population consists of 11 705 patients diagnosed with TGCTs. The median age at diagnosis was 37.7 yr. The standardized incidence rate of TGCTs increased significantly (p < 0.0001) from 4.1 (3.4, 4.8) per 100 000 in 1983 to 8.7 (7.9, 9.6) per 100 000 in 2018 by an average APC of 1.74 (1.20, 2.29). The joinpoint regression revealed a change point in time trend in 1995 with an APC of 4.24 (2.77, 5.72) before 1995 and an APC of 0.47 (0.06, 0.89) thereafter. Incidence rates were about twice as high for seminomas as for nonseminomas. A trend analysis by age group showed that the highest TGCT incidence rate was observed among men aged 30-40 yr, with a steep increase before 1995.

Conclusions

The incidence rate of TGCTs increased in Austria over the past decades and appears to have reached a plateau at a high level. A time trend analysis by age group for the overall incidence was highest in men aged 30-40 yr, with a steep increase before 1995. These data should lead to awareness campaigns and research to further investigate the causes of this development.

Patient summary

We reviewed the data between 1983 and 2018 provided by the Austrian National Cancer Registry to analyze the incidence and incidence trend in testicular cancer. Testicular cancer shows an increasing incidence in Austria. The overall incidence was highest in men aged 30-40 yr, with a steep increase before 1995. The incidence appears to have reached a plateau at a high level in recent years.

Maternal Serum α-Fetoprotein Levels during Pregnancy and Testicular Cancer in Male Offspring: A Cohort Study within a Danish Pregnancy Screening Registry

Testicular cancer is believed to originate from disruptions of normal androgen-estrogen balance in-utero. α-fetoprotein (AFP) may modify fetal response to estrogens via estrogen interaction. In a cohort study, we investigated the association between circulating maternal pregnancy AFP and testicular cancer risk in offspring. Of the 56,709 live-born males from a pregnancy screening registry in 1980-1995, our study included 50,519 singleton males with available second trimester blood samples from their mothers and complete covariate ascertainment. Testicular cancer diagnoses and covariate data were obtained from nationwide Danish health registries. Cox regression and Kaplan-Meier analyses estimated the prospective risk of testicular cancer (all, seminoma, nonseminoma) by AFP multiples of the median. During follow-up, 163 (0.3%) of the included males developed testicular cancer, of which 89 (54.6%) were nonseminomas. Maternal serum AFP levels greater than/equal to the median were associated with a relative risk of testicular cancer close to unity (RR 1.04, 95% CI 0.76; 1.41) compared to AFP below the median. Associations differed by type of testicular cancer (RR_seminoma 0.81, 95% CI 0.51; 1.29, RR_nonseminoma 1.31, 95% CI 0.85; 2.02). On balance, our findings do not support that serum AFP in pregnancy can be used as a predictor of testicular cancer in offspring.

On the origin of germ cell neoplasia in situ: Dedifferentiation of human adult Sertoli cells in cross talk with seminoma cells in vitro

Germ cell neoplasia in situ (GCNIS) is the noninvasive precursor of testicular germ cell tumors type II, the most common cancer in young men, which originates from embryonic germ cells blocked in their maturation. GCNIS is associated with impaired Sertoli cells (SCs) that express fetal keratin 18 (KRT18) and the pluripotency factor SRY-Box transcription factor 2 (SOX2). According to the current theory concerning the origin of GCNIS, these SCs are prepubertal cells arrested in their maturation due to (epi)genetic anomalies and/or environmental antiandrogens. Thus, they are unable to support the development of germ cells, which leads to their maturational block and further progresses into GCNIS. Alternatively, these SCs are hypothesized to be adult cells dedifferentiating secondarily under the influence of GCNIS. To examine whether tumor cells can dedifferentiate SCs, we established a coculture model of adult human SCs (FS1) and a seminoma cell line similar to GCNIS (TCam-2). After 2 wk of coculture, FS1 cells showed progressive expression of KRT18 and SOX2, mimicking the in vivo changes. TCam-2 cells showed SOX2 expression and upregulation of further pluripotency- and reprogramming-associated genes, suggesting a seminoma to embryonal carcinoma transition. Thus, our FS1/TCam-2 coculture model is a valuable tool for investigating interactions between SCs and seminoma cells. Our immunohistochemical and ultrastructural studies of human testicular biopsies with varying degrees of GCNIS compared to biopsies from fetuses, patients with androgen insensitivity syndrome, and patients showing normal spermatogenesis further suggest that GCNIS-associated SCs represent adult cells undergoing progressive dedifferentiation.

Trend analysis and regional tumor incidence in Germany for testicular cancer between 2003 and 2014

BACKGROUND

Testicular germ cell tumor (TGCT) is one the most common solid tumors in men between the age of 15 and 35 with an overall incidence rate of 1-1.5 %. Epidemiologic studies have demonstrated different incidence patterns in western civilized countries with overall rising incidence trends.

OBJECTIVE

To analyze differences in regional tumor incidence rates for TGCT and perform a trend analysis for TGCT between 2003 and 2014 in Germany.

MATERIAL AND METHODS

TGCT cases in Germany which were diagnosed between 2003 and 2014 were provided by the Robert-Koch-Institute, Berlin. For statistical analysis, cluster and spatial scan tests according to Kulldorff were used for cases with seminoma and non-seminoma. Results are presented in administrative districts and graphically illustrated. We performed a trend-analysis in order to evaluate age-adjusted incidence trends in Germany. Tests were two-sided with a level of significance of α=0.05.

RESULTS

In total we included 35,066 patients. Overall, 22,634 cases had newly diagnosed seminoma and 12,432 were diagnosed as non-seminoma. Maximum incidence of seminoma and non-seminoma was observed for age-group 38-40 years and 26-28 years, respectively. No second peak for the incidences of seminoma and non-seminoma with respect to age were observed. Cluster analysis revealed areas with high and low incidence rates as well as slightly different spatial distribution in Germany between seminoma and nonseminoma. Furthermore, there was no significant increase in age-adjusted incidence rates over the reviewed time period in both cohorts.

DISCUSSION

In this study differences in reginal tumor incidence rates for seminoma and non-seminoma are reported with both tumor entities revealing distinct clusters. Furthermore, tumor incidence trends for seminoma and nonseminoma between 2003 and 2014 were stable which might indicate the beginning of a plateau phase for TGCT incidence rates in Germany.

CONCLUSION

In this analysis we were able to identify regions with significantly higher tumor incidence rates for both seminoma and non-seminoma which were specific for these two subtypes. Furthermore, trend analysis revealed a steady incidence rate for testicular cancer in Germany.

International Trends in the Incidence of Testicular Cancer: Lessons from 35 Years and 41 Countries

BACKGROUND

Incidence rates of testicular cancer (TC) have been increasing in many countries since, at least, the mid-20th century without clear explanation. Examining the varying trends across countries and time provides clues to understanding the causes of TC.

OBJECTIVE

We have presented incidence data from 41 countries and evaluated incidence trends for the 35-yr period from 1978 to 2012.

DESIGN, SETTING, AND PARTICIPANTS

Cancer registry data from Cancer Incidence in Five Continents (CI5) volumes V-XI, CI5plus, and the NORDCAN database were analysed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Age-standardised rates of TC overall and by histological type were calculated. A joinpoint regression model of the natural log-transformed rates was used to calculate the average annual percent change (AAPC) in incidence. Age-period-cohort modelling was used to examine the effect of birth cohort on rates.

RESULTS AND LIMITATIONS

While the highest incidence of TC remains in Northern Europe, the gap is closing between higher- and lower-incidence regions. Age-period-cohort modelling found flattening of risk among recent cohorts in Denmark and the UK, a steady increase in risk in the USA (particularly for seminomas), and an increase in risk among more recent cohorts in Costa Rica, Croatia, and Slovakia.

CONCLUSIONS

The gap between low- and high-incidence countries is closing due to increases in the former and stabilisation in the latter. Understanding the causes of these and other differences in incidence rates between, and within, countries may help further our understanding of the aetiology of this cancer.

PATIENT SUMMARY

We examined the rates of testicular cancer in different countries over time. These rates have been increasing, although the rates in high-incidence countries seem to be slowing down, while rates in low-incidence countries are catching up. These trends might help us understand what is causing testicular cancer in general.

Ectopic activation of WNT signaling in human embryonal carcinoma cells and its effects in short- and long-term in vitro culture

Human embryonal carcinoma (EC) cells comprise the pluripotent stem cells of malignant non-seminomatous germ cell tumors (GCTs) and represent the malignant counterpart of embryonic stem cells (ESCs). WNT/β-catenin signaling has been implicated in regulating adult and embryonic stem cells although its role in EC cells is less investigated. Here, we studied WNT signaling in a panel of representative pluripotent and nullipotent human EC cell lines. We found that EC cell lines show distinct levels of intrinsic WNT signaling and respond differently to ectopic WNT activation. Short-term activation of WNT signaling induced a differentiation-response in the pluripotent EC cells (NT2 and NCCIT) whereas the nullipotent EC cells (TERA1 and 2102Ep) were refractory and maintained high levels of OCT4 and SSEA4 expression. Long-term activation of WNT signaling in NCCIT and, to a lesser extent, TERA1 cells led to (re)gain of OCT4 expression and a switch from SSEA4 to SSEA1 surface antigens ultimately resulting in OCT4⁺/SSEA4⁻/SSEA1⁺ profile. Cisplatin treatment indicated that the OCT4⁺/SSEA4⁻/SSEA1⁺ NCCIT cells became more resistant to chemotherapy treatment. Our findings are of particular interest for the GCT and ES cell biology and shed light on the role of WNT signaling in human EC cells.

m6A RNA modification and its writer/reader VIRMA/YTHDF3 in testicular germ cell tumors: a role in seminoma phenotype maintenance

BACKGROUND

Covalent RNA modifications, such as N-6-methyladenosine (m⁶A), have been associated with various biological processes, but their role in cancer remains largely unexplored. m⁶A dynamics depends on specific enzymes whose deregulation may also impact in tumorigenesis. Herein, we assessed the differential abundance of m⁶A, its writer VIRMA and its reader YTHDF3, in testicular germ cell tumors (TGCTs), looking for clinicopathological correlates.

METHODS

In silico analysis of TCGA data disclosed altered expression of VIRMA (52%) and YTHDF3 (48%), prompting subsequent validation. Formalin-fixed paraffin-embedded tissues from 122 TGCTs (2005-2016) were selected. RNA extraction, cDNA synthesis and real-time qPCR (Taqman assays) for VIRMA and YTHDF3 were performed, as well as immunohistochemistry for VIRMA, YTHDF3 and m⁶A, for staining intensity assessment. Associations between categorical variables were assessed using Chi square and Fisher's exact test. Distribution of continuous variables between groups was compared using the nonparametric Mann-Whitney and Kruskal-Wallis tests. Biomarker performance was assessed through receiver operating characteristics (ROC) curve construction and a cut-off was established by Youden's index method. Statistical significance was set at p < 0.05.

RESULTS

In our cohort, VIRMA and YTHDF3 mRNA expression levels differed among TGCT subtypes, with Seminomas (SEs) depicting higher levels than Non-Seminomatous tumors (NSTs) (p < 0.01 for both). A positive correlation was found between VIRMA and YTHDF3 expression levels. VIRMA discriminated SEs from NSTs with AUC = 0.85 (Sensitivity 77.3%, Specificity 81.1%, PPV 71.6%, NPV 85.3%, Accuracy 79.7%). Immunohistochemistry paralleled transcript findings, as patients with strong m⁶A immunostaining intensity depicted significantly higher VIRMA mRNA expression levels and stronger VIRMA immunoexpression intensity (p < 0.001 and p < 0.01, respectively).

CONCLUSION

Abundance of m⁶A and expression of VIRMA/YTHDF3 were different among TGCT subtypes, with higher levels in SEs, suggesting a contribution to SE phenotype maintenance. VIRMA and YTHDF3 might cooperate in m⁶A establishment in TGCTs, and their transcript levels accurately discriminate between SEs and NSTs, constituting novel candidate biomarkers for patient management.

Human Germ Cell Tumors are Developmental Cancers: Impact of Epigenetics on Pathobiology and Clinic

Current (high throughput omics-based) data support the model that human (malignant) germ cell tumors are not initiated by somatic mutations, but, instead through a defined locked epigenetic status, representative of their cell of origin. This elegantly explains the role of both genetic susceptibility as well as environmental factors in the pathogenesis, referred to as 'genvironment'. Moreover, it could also explain various epidemiological findings, including the rising incidence of this type of cancer in Western societies. In addition, it allows for identification of clinically relevant and informative biomarkers both for diagnosis and follow-up of individual patients. The current status of these findings will be discussed, including the use of high throughput DNA methylation profiling for determination of differentially methylated regions (DMRs) as well as chromosomal copy number variation (CNV). Finally, the potential value of methylation-specific tumor DNA fragments (i.e., XIST promotor) as well as embryonic microRNAs as molecular biomarkers for cancer detection in liquid biopsies will be presented.

International testicular cancer incidence rates in children, adolescents and young adults

BACKGROUND

Testicular cancer is the most common cancer in young men in developed countries. In adults, international variation in testicular cancer incidence rates has been well-described, while previous research on pediatric and adolescent testicular cancer has been more geographically limited.

METHODS

In this analysis, we used data from the three most recent volumes of Cancer Incidence in Five Continents (CI5) and the National Cancer Institute's SEER 18 registries to compare incidence rates for testicular cancer in children (ages 0-14) and adolescents and young adults (AYA; ages 15-39).

RESULTS

We find that geographic incidence patterns in AYA are different from patterns in children under 15. In AYA, incidence is highest in Europe (137.4 per million), followed by Oceania (116.9 per million), North America (94.9 per million), South and Central America (66.5 per million), and lowest in Asia (27.1 per million). In contrast, childhood incidence is highest in Asia (4.2 per million) and South America (5.0 per million) and lowest in Europe (2.1 per million) and North America (2.5 per million). In the United States, patterns in incidence rates in racial and ethnic groups mirror international rates.

CONCLUSION

These differences in incidence rate variations in pediatric and AYA testicular cancer are intriguing and may aid in understanding the different etiologies of testicular cancer by age group.

Testicular Cancer in New Zealand (TCNZ) study: protocol for a national case-control study

Testicular cancer (TC) is by far the most common cancer to affect young men; however, the exposures that cause this disease are still poorly understood. Our own research has shown that Māori men have the highest rates of this disease in New Zealand-a puzzling observation, since internationally TC is most commonly a disease of men of European ancestry. These trends provide us with a unique opportunity: to learn more about the currently unknown exposures that cause TC, and to explain why Māori have the highest rates of this disease in New Zealand. Using epidemiology and genetics, our experienced research team will conduct a nationwide study which aims to answer these internationally important questions.

AIM OF STUDY

The overall aim of the current national case-control study is to identify the key exposures in the development of TC in New Zealand, and explore which factors might explain the difference in the incidence of TC between Māori and non-Māori.

METHODS AND ANALYSIS

Outside of our own investigations into cryptorchidism, we still do not know which exposures are driving the significant incidence disparity between ethnic groups in NZ. The aim of the proposed research is to use a population-based case-control study to identify the key exposures in the development of TC in New Zealand. We will recruit 410 TC cases and 410 controls, and collect (1) environmental exposure data, via interview and (2) genetic information, via genome-wide genotyping.

ETHICS AND DISSEMINATION

Ethical approval for this study was sought and received from the New Zealand Ministry of Health's Health and Disability Ethics Committee (reference # 17/NTA/248). Following a careful data interpretation process, we will disseminate the findings of this study to a wide and varied audience ranging from general academia, community groups and clinical settings, as well as to the participants themselves.

Neonatal Hormone Concentrations and Risk of Testicular Germ Cell Tumors (TGCT)

Background: Testicular germ cell tumor (TGCT) incidence has increased over the last 40 years in the United States. In contrast to TGCT among infants, it is hypothesized that TGCT in adolescents and young men is the result of sex steroid hormone imbalance during early fetal development. However, little is known about the neonatal period when abrupt hormonal changes occur, and direct supporting evidence is scarce due to the difficulties in obtaining prediagnostic specimens.Methods: We conducted a population-based case-control study examining hormone levels at birth among 91 infants (0-4 years) and 276 adolescents (15-19 years) diagnosed with TGCT, and 344 matched controls. Estrogen and androgen levels were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS) from archived newborn dried blood spots. Logistic regression models were used to estimate the association between each hormone level and TGCT risk.Results: Higher levels of androstenedione were associated with increased TGCT risk among adolescents [odds ratio (OR): 2.33, 95% confidence interval (CI): 1.37-3.97 for highest vs. lowest quartile; P trend = 0.003] but not among infants (OR: 0.70, 95% CI: 0.28-1.77). A similar pattern was observed for testosterone (OR: 1.73, 95% CI: 1.00-3.00,) although the trend was not significant (P trend = 0.12). Associations were stronger among non-Hispanic white subjects, relative to Hispanics. There was no difference by tumor histologic subtype. Estriol (the only detectable estrogen) was not associated with TGCT risk in either age group.Conclusions: Higher levels of neonatal androgens were associated with increased risk of TGCT among adolescents, suggesting that early life hormone levels are related to the later development of TGCT.Impact: This is the first study with direct measures of sex steroid hormones to examine the relationship between estrogens and androgens at birth and risk of adolescent TGCT. Cancer Epidemiol Biomarkers Prev; 27(4); 488-95. ©2018 AACR.

Hereditary association between testicular cancer and familial ovarian cancer: A Familial Ovarian Cancer Registry study

BACKGROUND

Although family history of testicular cancer is well-established as a risk factor for testicular cancer, it is unknown whether family history of ovarian cancer is associated with risk of testicular cancer.

MATERIALS AND METHODS

Using data from the Familial Ovarian Cancer Registry on 2636 families with multiple cases of ovarian cancer, we systematically compared relative frequencies of ovarian cancer among relatives of men with testicular and non-testicular cancers.

RESULTS

Thirty-one families with cases of both ovarian and testicular cancer were identified. We observed that, among men with cancer, those with testicular cancer were more likely to have a mother with ovarian cancer than those with non-testicular cancers (OR = 3.32, p = 0.004). Zero paternal grandmothers of men with testicular cancer had ovarian cancer.

CONCLUSION

These observations provide compelling preliminary evidence for a familial association between ovarian and testicular cancers Future studies should be designed to further investigate this association and evaluate X-linkage.

Assessing the impact of in-utero exposures: potential effects of paracetamol on male reproductive development

Human male reproductive disorders (cryptorchidism, hypospadias, testicular cancer and low sperm counts) are common and some may be increasing in incidence worldwide. These associated disorders can arise from subnormal testosterone production during fetal life. This has resulted in a focus on in-utero environmental influences that may result in reproductive effects on the offspring in later life. Over recent years, there has been a dramatic increase in the scientific literature describing associations between in-utero environmental exposures (eg, industrial chemicals and pharmaceuticals) and subsequent reproductive outcomes in male offspring. This includes studies investigating a potential role for in-utero analgesic exposure(s) on the fetal testis; however, providing definitive evidence of such effects presents numerous challenges. In this review, we describe an approach to assessing the potential clinical relevance of in-utero (and postnatal) environmental exposures on subsequent male reproductive function using exposure to the analgesic paracetamol as an example.

Adherence to National Comprehensive Cancer Network® Guidelines for Testicular Cancer

PURPOSE

Testicular cancer is the most common malignancy among young men and well established treatment guidelines exist to optimize outcomes. We characterized errors in the management of testicular cancer observed among patients seen at 3 referral centers in the United States.

MATERIALS AND METHODS

We retrospectively reviewed data from 593 patients presenting with testicular cancer to 3 academic medical centers from 2007 to 2016. Nonguideline directed care was defined as management differing from National Comprehensive Care Network guideline recommendations. Cases of nonguideline directed care were systematically described. Patient and tumor characteristics were compared between guideline directed care and nonguideline directed care. Multivariable logistic regression was used to identify predictors of nonguideline directed care, and Cox regression modeling was used to assess the association between nonguideline directed care and relapse-free survival.

RESULTS

Nonguideline directed care was identified in 177 of 593 (30%) patients. Inappropriate imaging (44%) and overtreatment (40%) were the most common classifications. Misdiagnosis (24%) and under treatment (16%) occurred relatively frequently, while inappropriate treatment (6%) was rare. Multivariable Cox regression modeling controlling for race, tumor stage and tumor histology identified nonguideline directed care as a significant predictor of relapse (HR 2.49, 95% CI 1.61-3.85, p <0.01).

CONCLUSIONS

Nonguideline directed care of patients with testicular cancer is common, most frequently in the form of inappropriate imaging and overtreatment. Nonguideline directed care leads to delayed definitive therapy, unnecessary morbidity and higher rates of relapse.

Advances in the treatment of testicular cancer

Germ cell tumors (GCT) are relatively uncommon, accounting for only 1% of male malignancies in the United States. It has become an important oncological disease for several reasons. It is the most common malignancy in young men 15-35 years old. GCTs are among a unique numbers of neoplasms where biochemical markers play a critical role. Finally, it is a model of curable cancer. In this review we discuss cancer epidemiology, genetics, and therapeutic principles. Recent advances in the management of stage I GCT and controversies in the management of post chemotherapy residual mass are presented.

Obscure etiology, unusual disparity: the epidemiology of testicular cancer in New Zealand

PURPOSE

Testicular cancer (TC) remains perplexing, both in terms of what causes the disease and why certain populations are at greater risk of developing it. In New Zealand, an unusual ethnic disparity exists, whereby the indigenous Māori population suffer the highest rates of disease. In this study, we further describe the epidemiology of TC in the New Zealand context.

METHODS

Eligible patients diagnosed with TC between 2000 and 2011 (n = 1,800) were determined from the NZ Cancer Registry and linked to mortality data. Census data were used to estimate population incidence of TC and tumor sub-type by ethnic group. Kaplan-Meier and Cox regression analyses were used to compare survival between ethnic groups.

RESULTS

Māori males aged 15-44 were 80% more likely to be diagnosed with TC compared to European/Other males [age-standardized relative risk (RR) 1.80, 95% CI 1.58-2.05]. By contrast, disease burden was comparatively low among Pacific and Asian populations. Māori had a greater incidence of both seminoma (RR 1.88, 95% CI 1.52-2.22) and non-seminoma (RR 1.67, 95% CI 1.35-2.07) germ cell tumors than the European/Other population, reducing the likelihood that our observed disparity is driven by differential propensity to one given sub-type among Māori. Māori had poorer survival outcomes [cancer-specific adjusted hazard ratio (HR) 2.29, 95% CI 1.14-4.59] than the European/Other population.

CONCLUSIONS

Understanding the drivers of New Zealand's unusual incidence disparities--particularly between Māori and Pacific--could further our understanding of the key exposures involved in TC etiology.

[Testicular cancer - a matter of geography? Epidemiology and etiopathogenesis of germ cell tumors]

More than 90 % of testicular tumors are germ cell tumors. There is no doubt that ethnicity is one of the single overriding etiological factors in the development of these tumors. White males living in western industrialized countries, particularly in northern Europe show the highest incidence rates, whereas black males in Africa show the lowest. These differences are the result of interaction of genetic factors and exogenous noxious agents. Some of these agents are chemical substances with an estrogen-like effect. Many exogenous substances have been blamed for causing testicular cancer, but clear epidemiological evidence is lacking for most cases. Some well-established risk factors prevail, such as cryptorchidism, familial association, gonadal dysgenesis (intersex) and germ cell tumor in the contralateral testis. In terms of importance, overalimentation appears to outweigh occupation. The development of germ cell tumors is assumed to have an intrauterine origin through defect gonocytes which evolve into atypical germ cells of unclassified intratubular germ cell neoplasms. The trigger event is, however, the appearance of isochromosome 12p, which makes these cells aggressive and results in overt invasive testicular cancer.

International patterns and trends in testicular cancer incidence, overall and by histologic subtype, 1973-2007

Incidence rates of testicular cancer in Northern European and North American countries have been widely reported, whereas rates in other populations, such as Eastern Europe, Central/South America, Asia, and Africa, have been less frequently evaluated. We examined testicular cancer incidence rates overall and by histologic type by calendar time and birth cohort for selected global populations 1973-2007. Age-standardized incidence rates over succeeding 5-year periods were calculated from volumes 4-9 of Cancer Incidence in Five Continents electronic database (CI5plus) and the newly released CI5X (volume 10) database. Annual percent change over the 35-year period was calculated using weighted least squares regression. Age-period-cohort analyses were performed and observed rates and fitted rate ratios presented by birth cohort. Incidence rates of testicular cancer increased between 1973-1977 and 2003-2007 in most populations evaluated worldwide. Of note, incidence rates in Eastern European countries rose rapidly and approached rates in Northern European countries. Rates in Central and South America also increased and are now intermediate to the high rates among men of European ancestry and low rates among men of Asian or African descent. Some heterogeneity in the trends in seminoma and nonseminoma were observed in Denmark, the United Kingdom, and among US whites, particularly in recent generations, with rapid and uniform increases in the incidence of both histologic types in Slovakia. Reasons for the rising incidence rates among European and American populations remain unexplained; however, changing distributions in the prevalence of risk factors for testicular cancer cannot be ruled out.

Recent trends in the incidence of testicular germ cell tumors in the United States

Testicular germ cell tumors (TGCT), which comprise 98% of all testicular malignancies, are the most commonly occurring cancers among men between the ages of 15 and 44 years in the United States (US). A prior report from our group found that while TGCT incidence among all US men increased between 1973 and 2003, the rate of increase among black men was more pronounced starting in 1989-1993 than was the rate of increase among other men. In addition, TGCT incidence increased among Hispanic white men between 1992 and 2003. To determine whether these patterns have continued, in the current study, we examined temporal trends in incidence through 2011. Between 1992 and 2011, 21 271 TGCTs (12 419 seminomas; 8715 non-seminomas; 137 spermatocytic seminomas) were diagnosed among residents of the Surveillance, Epidemiology, and End Results 13 registry areas. The incidence of TGCT was highest among non-Hispanic white men (6.97 per 100 000 man-years) followed by American Indian/Alaska Native (AI/AN; 4.66), Hispanic white (4.11), Asian/Pacific Islander (A/PI; 1.95), and black (1.20) men. Non-Hispanic white men were more likely to present with smaller tumors (3.5 cm) and localized disease (72.6%) than were men of other races/ethnicities. Between 1992 and 2011, TGCT incidence increased significantly among Hispanic white [annual percent change (APC) = 2.94, p < 0.0001], black (APC = 1.67, p = 0.03), non-Hispanic white (APC = 1.23, p < 0.0001), and A/PI (APC = 1.04, p = 0.05) men. Incidence rates also increased, although not significantly, among AI/AN men (APC = 2.96, p = 0.06). The increases were greater for non-seminoma than seminoma. In summary, while non-Hispanic white men in the US continue to have the highest incidence of TGCT, they present at more favorable stages of disease and with smaller tumors than do other men. The increasing rates among non-white men, in conjunction with the larger proportion of non-localized stage disease, suggest an area where future research is warranted.

Gene-environment interactions in male reproductive health: special reference to the aryl hydrocarbon receptor signaling pathway

Over the last few decades, there have been numerous reports of adverse effects on the reproductive health of wildlife and laboratory animals caused by exposure to endocrine disrupting chemicals (EDCs). The increasing trends in human male reproductive disorders and the mounting evidence for causative environmental factors have therefore sparked growing interest in the health threat posed to humans by EDCs, which are substances in our food, environment and consumer items that interfere with hormone action, biosynthesis or metabolism, resulting in disrupted tissue homeostasis or reproductive function. The mechanisms of EDCs involve a wide array of actions and pathways. Examples include the estrogenic, androgenic, thyroid and retinoid pathways, in which the EDCs may act directly as agonists or antagonists, or indirectly via other nuclear receptors. Dioxins and dioxin-like EDCs exert their biological and toxicological actions through activation of the aryl hydrocarbon-receptor, which besides inducing transcription of detoxifying enzymes also regulates transcriptional activity of other nuclear receptors. There is increasing evidence that genetic predispositions may modify the susceptibility to adverse effects of toxic chemicals. In this review, potential consequences of hereditary predisposition and EDCs are discussed, with a special focus on the currently available publications on interactions between dioxin and androgen signaling.

Increasing incidence of testicular cancer in the United States and Europe between 1992 and 2009

PURPOSE

Increasing in incidence, testicular cancer is the most commonly diagnosed cancer in young men in the USA and in Europe. We sought to determine contemporary trends in testicular cancer incidence in the USA and Europe.

METHODS

Testicular cancer incidence data covering the USA and Europe were extracted from the SEER-13 (SEER*Stat 8.0.1) and the EUREG databases, respectively. Trends were determined using JoinPoint 3.5.3.

RESULTS

Testicular germ cell tumor (TGCT) incidence among US males >15 years increased from 1992 (5.7/100,000) to 2009 (6.8/100,000) with a significant annual percentage change (APC: 1.1%, p < 0.001). Seminomas were 29% of all TGCTs in 15-26 year-olds, increasing to 78% in those 40+ years of age. TGCT rates were highest in White men (1992: 7.5/100,000; 2009: 8.6/100,000) followed by Hispanic men (1992: 4.0/100,000; 2009: 6.3/100,000) and lowest among Asian (1992: 2.0/100,000; 2009: 2.8/100,000) and Black men (1992: 0.7/100,000; 2009: 1.7/100,000). Significantly increasing incidence rates were observed in White men (APC: 1.2%, p < 0.001) and most prominently in Hispanic men, especially from 2002 to 2009 (APC: 5.6%, p < 0.01). Incidence of testicular cancer increased in 15 of 19 (79%) European countries analyzed (p < 0.05). Denmark (13.4/100,000 man-years), Switzerland (12.7/100,000 man-years), and Norway (12.7/100,000 man-years) exhibited the highest age-standardized rates, while Spain had the greatest APC (APC = 5.5, 95% CI 3.9-7.0%, p < 0.001).

CONCLUSIONS

Between 1992 and 2009, testicular cancer incidence in the USA and Europe continued to increase, most notably in US Hispanic, Northern European, Spanish, and younger and older populations.

Increase in testicular germ cell tumor incidence among Hispanic adolescents and young adults in the United States

BACKGROUND

Although rising incidence rates of testicular germ cell tumors have been well documented in white men, relatively little is known about rates in men of Hispanic origin. In the current study, the authors compared germ cell tumor trends between men of Hispanic and non-Hispanic origin as a function of age at diagnosis.

METHODS

Trends in testicular germ cell tumor incidence among white men were analyzed according to Hispanic ethnicity in 2 data sets of the National Cancer Institute's Surveillance, Epidemiology, and End Results Program, spanning from 1992 to 2010 and from 2000 to 2010 and sampling 15% and 28% of the United States population, respectively. Rates were age-adjusted to the year 2000 US standard population.

RESULTS

Between 1992 and 2010, the annual incidence of testicular germ cell tumors among Hispanic whites ages 15 to 39 years increased 58%, from 7.18 cases per 100,000 in 1992 to 11.34 cases per 100,000 by 2010 (P<1 × 10(-9) ). Their incidence rates increased in metropolitan areas for both seminoma and nonseminoma subtypes and for all stages at diagnosis. During the same 19-year interval, incidence among non-Hispanic white young adults increased 7%, from 12.41 to 13.22 per 100,000. During the 2000 to 2010 interval, no significant trends were observed in incidence among non-Hispanic whites.

CONCLUSIONS

There has been a recent substantial increase in testicular germ cell tumor incidence among Hispanic adolescents and young adults in the United States. Similar trends were not observed in non-Hispanic whites.

Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice

Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼70% of control and induced atrophic seminiferous tubules in ∼30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.

Markedly increased incidence and improved survival of testicular cancer in the Netherlands

BACKGROUND

Worldwide marked changes have been observed in the incidence and survival of testicular cancer (TC) during the last decades. We conducted a study on trends in TC incidence, treatment, survival, and mortality in the Netherlands during the period 1970-2009 with specific focus on trends according to age, histology and stage of disease.

METHODS

Data from the Eindhoven cancer registry, the Netherlands cancer registry and Statistics Netherlands was used. Age-standardized incidence and mortality rates and five-year relative survival were calculated. Treatment was categorized into five major groups.

RESULTS

TC incidence showed a substantial annual increase of 3.9% in the period 1989-2009. The incidence increased for all stages of both seminoma and non-seminoma TC. Stage distribution for the non-seminoma patients shifted towards more localized disease. Most patients received primary treatment according to the guidelines. Five-year relative survival improved (non-significantly) for most groups of stage and histology. TC mortality dropped sharply in the 1970s and 1980s and remained relatively stable thereafter.

CONCLUSION

This study shows that incidence of TC has increased sharply in the Netherlands. Relative survival is high and improved in most disease stages. There is a growing demand for medical care of newly diagnosed TC patients and for the rapidly increasing number of prevalent TC patients.

Clinical profile, treatment and survival outcome of testicular tumors: a pakistani perspective

BACKGROUND

Testicular cancer management is considered a marvel of modern science with excellent treatment results. Pakistan has a distinct ethnic variation and geographic distribution but data regarding clinical presentation of testicular tumors and their management is under reported. The objective of this study was to determine clinical profile, treatment modalities and survival outcome of testicular tumors in the Pakistani population.

MATERIALS AND METHODS

A retrospective review of patients who received treatment for testicular cancer at Shaukat Khanum Cancer Hospital from January 2009 to December 2012 was performed. Patient demographics, clinical features at presentation and treatment modalities were assessed. For categorical variables chi square test was used. Survival was calculated using Kaplan Meier survival curves and Log rank test was employed to determine significance.

RESULTS

The most common tumor was mixed germ cell tumor in 49% patients. For all tumor variants except seminoma, stage III was the most common clinical stage at presentation. Majority of patients with non seminomatous germ cell tumors presented in the15-30 year age group as compared to seminoma which was most prevalent in the 30-40 year age group. Orchiectomy followed by chemotherapy was the most common treatment modality in 80% patients. Expected 5 year survival for seminomas and non- seminomatous germ cell tumors was 96% and 90% respectively which was not significantly different (p=0.2).

CONCLUSIONS

Despite a distinct clinical profile of testicular tumors in Pakistani population, survival is comparable with published reports.

Occupational and environmental exposures associated with testicular germ cell tumours: systematic review of prenatal and life-long exposures

Background

Testicular germ cell tumours (TGCT) are the most common cancers in men aged between 15 and 44 years and the incidence has increased steeply over the past 30 years. The rapid increase in the incidence, the spatial variation and the evolution of incidence in migrants suggest that environmental risk factors play a role in TGCT aetiology. The purpose of our review is to summarise the current state of knowledge on occupational and environmental factors thought to be associated with TGCT.

Methods

A systematic literature search of PubMed. All selected articles were quality appraised by two independent researchers using the ‘Newcastle-Ottawa Quality Assessment Scale’.

Results

After exclusion of duplicate reports, 72 relevant articles were selected; 65 assessed exposure in adulthood, 7 assessed parental exposures and 2 assessed both. Associations with occupation was reported for agricultural workers, construction workers, firemen, policemen, military personnel, as well as workers in paper, plastic or metal industries. Electromagnetic fields, PCBs and pesticides were also suggested. However, results were inconsistent and studies showing positive associations tended to had lower quality ranking using the assessment scale (p=0.02).

Discussion

Current evidence does not allow concluding on existence of any clear association between TGCT and adulthood occupational or environmental exposure. The limitations of the studies may partly explain the inconsistencies observed. The lack of association with adulthood exposure is in line with current hypotheses supporting the prenatal origin of TGCT. Future research should focus on prenatal or early life exposure, as well as combined effect of prenatal and later life exposure. National and international collaborative studies should allow for more adequately powered epidemiological studies. More sophisticated methods for assessing exposure as well as evaluating gene–environment interactions will be necessary to establish clear conclusion.

Do ethnic patterns in cryptorchidism reflect those found in testicular cancer?

PURPOSE

There are established variations in testicular cancer incidence between ethnic groups within countries. It is currently unclear whether the occurrence of cryptorchidism-a known risk factor for testicular cancer-follows similar patterns. In New Zealand Māori have unusually high rates of testicular cancer compared to individuals of European ancestry. We hypothesized that ethnic trends in the incidence of cryptorchidism would reflect those for testicular cancer in this setting.

MATERIALS AND METHODS

We followed 318,441 eligible male neonates born in New Zealand between 2000 and 2010 for the incidence of orchiopexy confirmed cryptorchidism and the incidence of known risk factors for cryptorchidism (low birth weight, short gestation, small size for gestational age) using routine maternity, hospitalization and mortality records. Logistic regression was used to calculate odds ratios for the presence of known risk factors for cryptorchidism by ethnic group. Poisson regression was used to calculate relative risk of cryptorchidism by ethnicity, adjusted for risk factors.

RESULTS

Ethnic patterns of cryptorchidism incidence in New Zealand closely mirrored those previously observed for testicular cancer. Māori had higher rates of cryptorchidism than all other ethnic groups (adjusted RR 1.2 [95% CI 1.11-1.3]), with Pacific (0.89 [0.8-0.99]) and Asian groups (0.68 [0.59-0.79]) having the lowest rates (European/other, referent).

CONCLUSIONS

Since the principal risk factors for cryptorchidism are present in utero, the results of the current study strengthen the likelihood that the ethnic patterning of testicular cancer is at least partly due to prenatal risk factors.

Testicular germ cell tumor susceptibility associated with the UCK2 locus on chromosome 1q23

Genome-wide association studies (GWASs) have identified multiple common genetic variants associated with an increased risk of testicular germ cell tumors (TGCTs). A previous GWAS reported a possible TGCT susceptibility locus on chromosome 1q23 in the UCK2 gene, but failed to reach genome-wide significance following replication. We interrogated this region by conducting a meta-analysis of two independent GWASs including a total of 940 TGCT cases and 1559 controls for 122 single-nucleotide polymorphisms (SNPs) on chromosome 1q23 and followed up the most significant SNPs in an additional 2202 TGCT cases and 2386 controls from four case-control studies. We observed genome-wide significant associations for several UCK2 markers, the most significant of which was for rs3790665 (PCombined = 6.0 × 10(-9)). Additional support is provided from an independent familial study of TGCT where a significant over-transmission for rs3790665 with TGCT risk was observed (PFBAT = 2.3 × 10(-3)). Here, we provide substantial evidence for the association between UCK2 genetic variation and TGCT risk.

Risk of germ cell testicular cancer according to origin: a migrant cohort study in 1,100,000 Israeli men

Testicular cancer incidence is highest among men of northern European ancestry and lowest among men of Asian/African descent. We conducted a large-scale migrant cohort study to assess origin and migrant generation as predictors of testicular germ cell tumors (TGCTs), controlling for possible confounders. Data on 1,092,373 Jewish Israeli males, who underwent a general health examination prior to compulsory military service at ages 16-19 between the years 1967-2005, were linked to Israel National Cancer Registry to obtain incident TGCTs up to 2006. Cox proportional hazards was used to model time to event. Overall, 1,001 incident cases (534 seminoma and 467 nonseminoma) were detected during 19.2 million person-years of follow-up. Origin was a strong independent predictor of TGCTs with remarkably low incidence for North African-born (HR = 0.10, 95% CI: 0.04-0.21) and Asian-born (HR = 0.35, 0.20-0.62), while intermediate for Israeli-born of North African origin (HR = 0.48, 0.40-0.58) and Asian origin (HR = 0.56, 0.47-0.66), compared to European origin. A comparison of Israeli born of North African and Asian origin with North African and Asian-born yielded a HR of 2.31 (1.36-3.93). Significant risk factors controlled for were year of birth, years of education and height. Findings persisted when analyses were stratified by histologic subtypes of TGCTs. The findings of lower rates of TGCTs among men born in North Africa and Asia compared to European ancestry, but a steep increase in next generation migrants, particularly among the Israeli-born migrants from North Africa, provide clues to direct further research on the role of modern lifestyle and environment in the etiology of TGCTs.

Male reprotoxicity and endocrine disruption

Mammalian reproductive tract development is a tightly regulated process that can be disrupted following exposure to drugs, toxicants, endocrine-disrupting chemicals (EDCs), or other compounds via alterations to gene and protein expression or epigenetic regulation. Indeed, the impacts of developmental exposure to certain toxicants may not be fully realized until puberty or adulthood when the reproductive tract becomes sexually mature and altered functionality is manifested. Exposures that occur later in life, once development is complete, can also disrupt the intricate hormonal and paracrine interactions responsible for adult functions, such as spermatogenesis. In this chapter, the biology and toxicology of the male reproductive tract is explored, proceeding through the various life stages including in utero development, puberty, adulthood, and senescence. Special attention is given to the discussion of EDCs, chemical mixtures, low-dose effects, transgenerational effects, and potential exposure-related causes of male reproductive tract cancers.

Trends in testicular germ cell tumors among U.S. military servicemen, 1990-2003

OBJECTIVE

To determine the incidence of testicular germ cell tumors among active duty males and compare it with the incidence in the general U.S. population.

METHODS

The Automated Cancer Tumor Registry and the Surveillance, Epidemiology, and End Results Program data from 1990 to 2003 were analyzed for men aged between 20 and 59 years by histology and stage at diagnosis. Rates were age adjusted using the male active duty military population as the standard.

RESULTS

Nonseminoma incidence was significantly lower in the military than in the general population (incidence rate ratio = 0.90, 95% confidence interval = 0.82-0.98). Trends in incidence tended to be similar in both the populations. Increases were observed for both histologic types but were only significant for seminoma (Automated Cancer Tumor Registry: 21% and Surveillance, Epidemiology, and End Results program: 16%; p < 0.05). Increases in incidence were only observed for localized tumors of both histologic types.

CONCLUSIONS

The lower incidence of nonseminoma in the military and the increased incidence of localized tumors in both populations remain unexplained.

Age-specific incidence data indicate four mutations are required for human testicular cancers

Normal human cells require a series of genetic alterations to undergo malignant transformation. Direct sequencing of human tumors has identified hundreds of mutations in tumors, but many of these are thought to be unnecessary and a result of, rather than a cause of, the tumor. The exact number of mutations to transform a normal human cell into a tumor cell is unknown. Here I show that male gonadal germ cell tumors, the most common form of testicular cancers, occur after four mutations. I infer this by constructing a mathematical model based upon the multi-hit hypothesis and comparing it to the age-specific incidence data. This result is consistent with the multi-hit hypothesis, and implies that these cancers are genetically or epigenetically predetermined at birth or an early age.

Bridging epidemiology and model organisms to increase understanding of endocrine disrupting chemicals and human health effects

Concerning temporal trends in human reproductive health has prompted concern about the role of environmentally mediated risk factors. The population is exposed to chemicals present in air, water, food and in a variety of consumer and personal care products, subsequently multiple chemicals are found human populations around the globe. Recent reviews find that endocrine disrupting chemicals (EDCs) can adversely affect reproductive and developmental health. However, there are still many knowledge gaps. This paper reviews some of the key scientific concepts relevant to integrating information from human epidemiologic and model organisms to understand the relationship between EDC exposure and adverse human health effects. Additionally, areas of new insights which influence the interpretation of the science are briefly reviewed, including: enhanced understanding of toxicity pathways; importance of timing of exposure; contribution of multiple chemical exposures; and low dose effects. Two cases are presented, thyroid disrupting chemicals and anti-androgens chemicals, which illustrate how our knowledge of the relationship between EDCs and adverse human health effects is strengthened and data gaps reduced when we integrate findings from animal and human studies.

Management of stage I testicular seminoma

Adjuvant treatment options for stage I seminoma include surveillance, radiation, and hemotherapy. Despite excellent results for both adjuvant chemotherapy and radiotherapy, many concerns have been raised in regards to the potential long-term toxicities of these treatments. To minimize the burden of treatment, there has been a shift away from adjuvant treatments for stage I testicular seminomas toward surveillance protocols for seminoma survivors. This article reviews the evidence for all adjuvant treatment options for stage I testicular seminomas with a particular focus on surveillance.

Intratubular germ cell neoplasms of the testis and bilateral testicular tumors: clinical significance and management options

Objectives:

Intratubular germ cell neoplasia (ITGCN) is the precursor lesion for invasive testicular germ cell tumors (TGCTs) of adolescents and young adults. The rising incidence of these tumors has prompted a rigorous investigation of the etiology, diagnosis and management of ITGCN. Bilateral testicular cancer is closely linked with ITGCN, as patients with unilateral testicular cancer are at the highest risk for a future malignancy in the contralateral testicle.

Methods:

A literature review directed at ITGCN and bilateral testis cancer was performed using the Medline/PubMed database. Our review focused on the pathogenesis, risk factors, diagnosis and treatment regimens utilized.

Results:

Major advances have been made in the understanding of ITGCN over the past 30 years. There is evidence that TGCTs arise from ITGCN, ITGCN is closely related to fetal gonocytes, and that events in pre- and perinatal period may result in abnormal persistence of fetal gonocytes leading to ITGCN and subsequent TGCT. Controversy exists regarding the need to biopsy men at increased risk of TGCT, as well as the best approach to managing patients with known ITGCN. Bilateral testicular cancer has excellent outcomes in the current era of platinum-based chemotherapy.

Conclusion:

The optimal management of patients at risk for ITGCN and future TGCT is still a matter of debate. Individualization of management, including biopsy and treatment, should be based on risk factors for TGCT, compliance with potential surveillance, and patient preferences particularly with regard to fertility.

Dissecting the molecular pathways of (testicular) germ cell tumour pathogenesis; from initiation to treatment-resistance

Human type II germ cell tumours (GCTs) originate from an embryonic germ cell, either as a primordial germ cell or gonocyte. This start determines the biological as well as clinical characteristics of this type of cancer, amongst others their totipotency as well as their overall (exceptional) sensitivity to DNA damaging agents. The histology of the precursor lesion, either carcinoma in situ or gonadoblastoma, depends on the level of testicularization (i.e. testis formation) of the gonad. The impact of either intrinsic (genetic) - and environmental factors involved in the pathogenesis is demonstrated by disorders of sex development as well as testicular dysgenesis syndrome as risk factors, including cryptorchidism, hypospadias and disturbed fertility as parameters. This knowledge allows identification of individuals at risk for development of this type of cancer, being a population of interest for screening. Factors known to regulate pluripotency during embryogenesis are proven to be of diagnostic value for type II GCTs, including OCT3/4, even applicable for non-invasive screening. In addition, presence of stem cell factor, also known as KITLG, allows distinction between delayed matured germ cells and the earliest stages of malignant transformation. This is of special interest because of the identified association between development of type II GCTs of the testis and a limited number of single nucleotide polymorphisms, including some likely related to KITL. Transition from the precursor lesion to an invasive cancer is associated with gain of the short arm of chromosome 12, in which multiple genes might be involved, including KRAS2 and possibly NANOG (pseudogenes). While most precursor lesions will progress to an invasive cancer, only a limited number of cancers will develop treatment resistance. Putative explanatory mechanisms are identified, including presence of microsatellite instability, BRAF mutations, apoptosis suppression and p21 sub-cellular localization. It remains to be investigated how these different pathways integrate to each other and how informative they are at the patient-individual level. Further understanding will allow development of more targeted treatment, which will benefit quality of life of these young cancer patients.

Reproductive environmental health

PURPOSE OF REVIEW

There is heightened recognition that the environment is an important driver of human reproductive health. This article provides an overview of the nature and extent of the science in the field of reproductive environmental health and its implications for OB/GYN clinical practice.

RECENT FINDINGS

Women of childbearing age incur ubiquitous contact to numerous toxic environmental contaminants. Even subtle perturbations caused by chemical exposures during critical and sensitive windows of development may lead to increased risks of disease and disability across the entire span of human life. The strength of the evidence is sufficiently high that leading scientists and clinicians have called for timely action to prevent harm.

SUMMARY

OB/GYNs are uniquely poised to intervene in critical stages of human development (i.e., preconception and during pregnancy) to prevent harm. Efforts are underway to provide clinicians with the evidence-based foundation to develop recommendations for prevention. If adopted, current directions in toxicity testing, risk assessment and policy are likely to create important changes in how environmental chemicals are evaluated and regulated in the future. Together, these changes have the potential to assist in clinical assessment of patient risk and reductions in patient exposure to environmental contaminants linked to adverse reproductive health outcomes.

A systematic review and meta-analysis of the relationship between body size and testicular cancer

Background:

Studies assessing the relationships of anthropometry and testicular germ-cell tumour (TGCT) have reported heterogeneous findings.

Methods:

We undertook a systematic review and meta-analysis of the associations between adult height, weight, body mass index (BMI), and testicular cancer. Search strategies were conducted in PubMed, EMBASE, Scopus, and Web of Science on 26 May 2009. Studies that met our inclusion criteria were included in meta-analytic models using STATA 11.

Results:

A total of 3255 references were retrieved, of which 14 met the inclusion criteria. Random effects meta-analysis found adult height (odds ratio (OR) per 5-cm increase 1.13, 95% confidence interval (CI) 1.07–1.19, P<0.001) and weight (OR overweight vs normal 0.92, 95% CI 0.86–0.98, P=0.011) to be associated with TGCT. The meta-analysis of weight and TGCT produced a summary estimate, which indicated no association, although an analysis restricted studies to North American was suggestive of association (OR per 1-kg increase 1.01, 95% CI 1.00–1.01, P<0.001).

Conclusions:

This systematic review and meta-analysis has found evidence for a positive association of adult height and TGCT, and tentative evidence for an inverse association of BMI and TGCT.

Trends in incidence and survival of pediatric and adolescent patients with germ cell tumors in the United States, 1975 to 2006

BACKGROUND

Pediatric germ cell tumors (GCTs) are rare and heterogeneous tumors with uncertain etiology. In the current study, data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program were used to evaluate trends in incidence and survival of GCTs in boys and girls ages ≤19 years. To the authors' knowledge, few studies to date have evaluated trends in pediatric GCTs. Results from these analyses may provide clues to the etiology of GCTs.

METHODS

Frequencies, incidence rates, and 5-year relative survival rates stratified by sex were evaluated overall and by demographic subgroups based on age (birth to 9 years and 10-19 years), race (white, black, and other), and ethnicity (non-Hispanic and Hispanic) as sample size permitted.

RESULTS

In whites, the incidence of GCTs was lower for females than males in the 10-year to 19-year age group (rate ratio [RR], 0.47; 95% confidence interval [95% CI], 0.42-0.53), whereas the rates were similar in the age group for birth to 9 years. In contrast, incidence rates were higher in black females than in black males in both age groups (RR, 2.01 [95%CI, 1.08-3.84] in those ages birth to 9 years; RR, 3.30 [95% CI, 2.13-5.28] in those ages 10-19 years). The incidence of ovarian GCT was significantly higher in Hispanic compared with non-Hispanic girls in the groups aged 10 to 19 years. Incidence rates increased during the study period in boys ages 10 to 19 years (annual percentage change [APC], 1.2; 95% CI, 0.4-2.1) and girls ages birth to 9 years (APC, 1.9; 95% CI, 0.3-2.5).

CONCLUSIONS

The incidence of pediatric GCTs in the United States appears to be increasing only in certain subgroups, suggesting that the etiology is not completely overlapping in all age groups. Differences in incidence patterns by race and ethnicity merit further investigation.

International trends in the incidence of testicular cancer, 1973-2002

BACKGROUND

Whereas testicular cancer incidence rates have been widely reported in populations of Northern European ancestry, rates in other populations have been less frequently examined. In a prior report, global testicular cancer incidence rates and trends for the years 1973 to 1997 were summarized. The current report extends these analyses with an additional 5 years of data from Cancer Incidence in Five Continents.

METHODS

Age-standardized incidence rates over successive 5-year time periods were obtained for populations in the Americas, Asia, Europe, and Oceania.

RESULTS

In general, testicular cancer incidence remained highest in Northern European populations (8.0-9.0 per 100,000) and lowest in Asian and African populations (<1 per 100,000). One notable exception to this pattern, however, was the very high rate reported by the Valdivia, Chile registry (8.8 per 100,000). In many populations, rates rose between 1973 and 2002, although the increases were strongest and most consistent among populations of European ancestry. In certain European populations, such as those of Denmark and of Geneva, Switzerland, some recent plateauing of rates was evident. There was little evidence of increase and possible evidence of a modest decline in rates among east Asian populations. Trends by histology (seminoma and nonseminoma) were generally similar to one another.

CONCLUSIONS

Risk of testicular cancer remains relatively high in Northern European populations and low in Asian and African populations. Similar trends by histology suggest common risk factors. EFFECT: Reasons for increasing rates among Northern Europeans and stable or declining rates among East Asians are unexplained, supporting the need for future etiologic studies.

Ethnic and socioeconomic trends in testicular cancer incidence in New Zealand

Ethnic differences in testicular cancer incidence within countries are often sizeable, with white populations consistently having the highest ethnic-specific rates. Many studies have found that high socioeconomic status is a risk factor for testicular cancer. The objectives of this article are to test whether trends in testicular cancer incidence have varied by ethnicity and socioeconomic position in New Zealand between 1981 and 2004. Five cohorts of the entire New Zealand population for 1981-1986, 1986-1991, 1991-1996, 1996-2001 and 2001-2004 were created, and probabilistically linked to cancer registry records, allowing direct determination of ethnic and household income trends in testicular cancer incidence. There were more than 2,000 cases of testicular cancer over the study period. We found increasing rates of testicular cancer for all ethnic and income groups since 1990s. Maori had higher rates, and Pacific and Asian lower rates than European/other men with rate ratios pooled over time of 1.51 (95% CI 1.31-1.74), 0.40 (95% CI 0.26-0.61) and 0.54 (95% CI 0.31-0.94), respectively. Overall, men with low incomes had higher risk of testicular cancer than those with high incomes (pooled rate ratio for lowest to highest income groups = 1.23; 95% CI 1.05-1.44). There was no strong evidence that disparities in testicular cancer incidence have varied by ethnicity or household income over time. Given the lack of understanding of the etiology of testicular cancer, the unusual patterns identified in the New Zealand context may provide some etiological clues for future novel research.

Familial testicular germ cell tumours

This article defines familial testicular germ cell tumours (FTGCTs) as testicular germ cell tumours (TGCTs) diagnosed in at least two blood relatives, a situation which occurs in 1-2% of all cases of TGCT. Brothers and fathers of TGCT patients have an 8-10- and 4-6-fold increased risk of TGCT, respectively, and an even higher elevated risk of TGCT in twin brothers of men with TGCT has been observed, suggesting that genetic elements play an important role in these tumours. Nevertheless, previous linkage studies with multiple FTGCT families did not uncover any high-penetrance genes and it has been concluded that the combined effects of multiple common alleles, each conferring a modest risk, might underlie FTGCT. In agreement with this assumption, recent candidate gene-association analyses have identified the chromosome Y gr/gr deletion and mutations in the PDE11A gene as genetic modifiers of FTGCT risk. Moreover, two genome-wide association studies of predominantly sporadic but also familial cases of TGCT have identified three additional susceptibility loci, KITLG, SPRY4 and BAK1. Notably, all five loci are involved in the biology of primordial germ cells, representing the cell of origin of TGCT, suggesting that the tumours arise as a result of disturbed testicular development.

Incidence of testicular cancer in the United States, 1999-2004

Testicular cancer is rare but primarily affects young men. To characterize the current incidence of testicular cancer in the United States, U.S. Cancer Statistics data from 1999 through 2004 were examined. Age-adjusted (2000 U.S. standard) incidence rates were calculated for seminoma and nonseminoma testicular germ cell tumors (TGCTs). Hispanic men had the largest increase in incidence rates for nonseminomas, followed by non-Hispanic White men (annual percentage change of 3.2% and 1.9%, respectively, p < .05). Nonseminomas peaked at a younger age for Hispanic, American Indian/Alaska Native (AIAN), and Asian/Pacific Islander (API) men. Whereas 9.6% of TGCTs were diagnosed at a distant stage in non-Hispanic White men, more Hispanic (16.1%), Black (13.8%), AIAN (16.8%), and API (14.9%) men with TGCTs were diagnosed with distant stage. Monitoring incidence rates for rare cancers by race/ethnicity has improved with national population-based cancer registry coverage. Disparities in diagnosis stage have implications for effective treatment of TGCTs.