Doubling of testicular cancer incidence rate over the last 20 years in southern France

Endocrine-disrupting chemicals affect sertoli TM4 cell functionality through dysregulation of gap junctional intercellular communication in vitro

The frequencies of adverse outcomes associated with male reproductive health, including infertility and testicular cancer, are increasing. These adverse trends are partially attributed to increased exposure to environmental agents such as endocrine-disrupting chemicals (EDCs). This study addresses effects on EDCs on adjacent prepubertal Sertoli TM4 cells, specifically on 1) testicular gap junctional intercellular communication (GJIC), one of the hallmarks of non-genotoxic carcinogenicity, 2) GJIC building blocks connexins (Cx), and 3) mitogen-activated protein kinases MAPKs. We selected eight representatives of EDCs: bisphenol A and organochlorine chemicals such as pesticides dichlorodiphenyltrichloroethane, lindane, methoxychlor, and vinclozolin, industrial chemical 2,2',4,4',5,5'-hexachlorobiphenyl, and components of personal care products, triclocarban and triclosan. EDCs rapidly dysregulated GJIC in Sertoli TM4 cells mainly via MAPK p38 and/or Erk1/2/pathways by the intermediate hyper- or de-phosphorylation of Cx43 (Ser368, Ser282) and translocalization of Cx43 from the plasma membrane, suggesting disturbed intracellular trafficking of Cx43 protein. Surprisingly, EDCs did not rapidly activate MAPK Erk1/2 or p38; on the contrary, TCC and TCS decreased their activity (phosphorylation). Our results indicate that EDCs might disrupt testicular homeostasis and development via testicular GJIC, junctional and non-junctional functions of Cx43 and MAPK-signalling pathways in Sertoli cells.

Contribution of Apaf-1 to the pathogenesis of cancer and neurodegenerative diseases

Deregulation of apoptosis is associated with various pathologies, such as neurodegenerative disorders at one end of the spectrum and cancer at the other end. Generally speaking, differentiated cells like cardiomyocytes, skeletal myocytes and neurons exhibit low levels of Apaf-1 (Apoptotic protease activating factor 1) protein suggesting that down-regulation of Apaf-1 is an important event contributing to the resistance of these cells to apoptosis. Nonetheless, upregulation of Apaf-1 has not emerged as a common phenomenon in pathologies associated with enhanced neuronal cell death, i.e., neurodegenerative diseases. In cancer, on the other hand, Apaf-1 downregulation is a common phenomenon, which occurs through various mechanisms including mRNA hyper-methylation, gene methylation, Apaf-1 localization in lipid rafts, inhibition by microRNAs, phosphorylation, and interaction with specific inhibitors. Due to the diversity of these mechanisms and involvement of other factors, defining the exact contribution of Apaf-1 to the development of cancer in general and neurodegenerative disorders, in particular, is complicated. The current review is an attempt to provide a comprehensive image of Apaf-1's contribution to the pathologies observed in cancer and neurodegenerative diseases with the emphasis on the therapeutic aspects of Apaf-1 as an important target in these pathologies.

Assessment of the Emerging Threat Posed by Perfluoroalkyl and Polyfluoroalkyl Substances to Male Reproduction in Humans

Per-fluoroalkyl and polyfluoroalkyl substances (PFAS) are a diverse group of synthetic fluorinated chemicals used widely in industry and consumer products. Due to their extensive use and chemical stability, PFAS are ubiquitous environmental contaminants and as such, form an emerging risk factor for male reproductive health. The long half-lives of PFAS is of particular concern as the propensity to accumulate in biological systems prolong the time taken for excretion, taking years in many cases. Accordingly, there is mounting evidence supporting a negative association between PFAS exposure and an array of human health conditions. However, inconsistencies among epidemiological and experimental findings have hindered the ability to definitively link negative reproductive outcomes to specific PFAS exposure. This situation highlights the requirement for further investigation and the identification of reliable biological models that can inform health risks, allowing sensitive assessment of the spectrum of effects of PFAS exposure on humans. Here, we review the literature on the biological effects of PFAS exposure, with a specific focus on male reproduction, owing to its utility as a sentinel marker of general health. Indeed, male infertility has increasingly been shown to serve as an early indicator of a range of co-morbidities such as coronary, inflammatory, and metabolic diseases. It follows that adverse associations have been established between PFAS exposure and the incidence of testicular dysfunction, including pathologies such as testicular cancer and a reduction in semen quality. We also give consideration to the mechanisms that render the male reproductive tract vulnerable to PFAS mediated damage, and discuss novel remediation strategies to mitigate the negative impact of PFAS contamination and/or to ameliorate the PFAS load of exposed individuals.

Developing the "Control Identity" Typology to Create More Effective Testicular Health Promotional Messaging

Testicular self-examination (TSE) promotional interventions historically operate without a theoretical framework, which negatively influences their effectiveness. As TSE is critical to the early detection of testicular cancer, this behavior is an essential component to improving overall male well-being. To address this need, the Control Identity personality typology was developed to assist in creating more effective TSE promotional interventions. Four outcome control dispositions were defined a priori based on the dimensions of illusions of control and locus of control. An original 41-item survey, the Control Identity Assessment Scale, was used to assess perceived vulnerability, value of health promotion, and health outcome control among a convenience sample of 300 university males aged 18 to 35 years via a cross-sectional research design. Factor and cluster analyses were employed to extract salient factors in the data and to identify subgroups within the sample. A consistent five-factor structure matrix (~70% explained variance) served as the foundation from which a k-means cluster analysis was employed to classify four types of individuals. Significant differences were detected between clusters on primary variables, including behavioral intentions to conduct TSE. The Control Identity typology aims to provide the needed mechanism for health practitioners to create more effective preventive health messaging to promote TSE. Future implications on employing this typology to segment audiences in order to increase overall effectiveness are offered. Application of this typology could ultimately lead to increasing TSE knowledge retention, behavioral intentions, actual performance, and adherence.

Cancer Mortality in Italy, 1970–2002

Aims and background

To update previous work on Italian cancer mortality.

Methods

WHO data were used to calculate death rates for 30 cancer sites for 2002. Trends were analyzed with joinpoint regression over the 1970–2002 period.

Results

Total cancer deaths for 2002 in Italy were 163,070 (93,398 men, 69,672 women). Male cancer mortality rose until 1988 and since then has had a 1.4% yearly fall. The first cause of cancer death in males was lung cancer, accounting for 28% of deaths. The decrease in mortality from male lung cancer came about the end of the 1980's (estimated annual percentage change, EAPC, −1.26 from 1989 to 1993 and −2.32 thereafter) and was the main reason for the favorable trends in total male cancer mortality, reflecting the change in smoking prevalence in Italian males. Female total cancer mortality trends have also been favorable, with an overall yearly drop of 1.1% since 1992. The most frequent causes of cancer deaths in females were breast and colorectal cancers, accounting for 16% and 14% of cancer deaths, and both showed declining trends (EAPC, −1.80 since 1992 and −1.51 from 1993 for breast and colorectal cancers, respectively). Female lung cancer has been on the rise (EAPC, 0.82 since 1987) for the last decades due to the rise in cigarette smoking since the 1970's in Italian females.

Discussion

Mortality from the most common cancers in Italy showed a favorable trend over recent years, the maintenance and potential improvement of which would require a strategy focusing on the control of tobacco and alcohol consumption, nutrition and diet. Early diagnosis for selected neoplasms can also have a relevant impact, together with advancements in treatments.

Histopathological Trends of Testicular Neoplasm: An Experience over a Decade in a Tertiary Care Centre in the Malwa Belt of Central India

INTRODUCTION

Testicular and para-testicular neoplasm are rare type of tumours affecting adolescents and young adults, reflected by the paucity of published data in India.

AIM

This study was undertaken to estimate the epidemiological characteristics and histological types and subtypes of testicular neoplasm according to the WHO classification in our patient group. Identification of histopathological pattern of testicular tumour is immensely important for improved management protocols.

MATERIALS AND METHODS

This was a retrospective study done over a period of ten years from 2004 to 2014 in a tertiary care centre. All relevant clinical data including patient's age, laterality, history of risk factors and serum tumour markers were collected from records. Histopathological slides were retrieved and reviewed for tumour and its subtype and classified according to WHO classification (2004).

RESULTS

A total of 37 cases of testicular and paratesticular neoplasm were encountered in our study with a mean age of 38.1 years. Right testis was affected in 70.3% of cases. The most common clinical presentation was scrotal swelling with heaviness. Germ cell tumour was the most common type accounting for 77.1% followed by lymphomas (17.1%). Germ cell tumours were categorized into seminomatous (48.2%) and non-seminomatous tumours (51.8%). The most common subtype of non-seminomatous tumours was mixed germ cell tumour accounting for 85.8%.

CONCLUSION

The incidence of testicular neoplasm among general population in Asian countries is low, as reflected in the very few studies that have been performed and published in literature. Epidemiological and histomorphological spectrum of our study was comparable to most of the countries except for some African and Western countries.

Recommendations for Treating Males: An Ethical Rationale for the Inclusion of Testicular Self-Examination (TSE) in a Standard of Care

The phrase "standard of care" is primarily a legal term representing what procedure a reasonable person (i.e., health practitioner) would administer to patients across similar circumstances. One major concern for health practitioners is delivering and advocating for treatments not defined as a standard of care. While providing such treatments may meet certain ethical imperatives, doing so may unwittingly trigger medical malpractice litigation fears from practitioners. Apprehension to deviate, even slightly, from the standard of care may (seem to) put the practitioner at significant risk for litigation, which, in turn, may limit options for treatment and preventive measures recommended by the practitioner. Specific to testicular treatment, certain guidelines exist for cancer, torsion, vasectomy, and scrotal masses, among others. As it relates to screening, practitioner examination is expected for patients presenting with testicular abnormalities. Testicular self-examination (TSE) advocacy, however, is discouraged by the U.S. Preventive Services Task Force, which may prompt a general unwillingness among health practitioners to promote the behavior. Considering the benefits TSE has beyond cancer detection, and the historical support it has received among health practitioners, it is paramount to consider the ethical implications of its official "exclusion" from preventive health and clinical care recommendations (i.e., standard of care). Since good ethics should lead practitioner patient care guidelines, not fear of increased malpractice risks, we recommend the development of a standard of care for counseling males to perform TSE.

Distribution of testicular tumors in Lebanon: a single institution overview

BACKGROUND

Testicular tumors constitute a rare type of cancer affecting adolescents and young adults with recent reports confirming an increase in incidence worldwide. The purpose of this study was to estimate the epidemiological characteristics and histological subtypes of testicular tumors in the Lebanese population according to the WHO classification of testicular and paratesticular tumors.

MATERIALS AND METHODS

In this single institutional retrospective study, all patients diagnosed with a testicular tumor in Hotel-Dieu de France Hospital University in Beirut between 1992 and 2014 were enrolled. The age, subtype based on the 2004 WHO classification and body side of tumor were analyzed.

RESULTS

A total of two hundred and forty-four (244) patients diagnosed with a testicular tumor in our institution were included in the study. Two hundred and one patients (82.4% of all testicular tumors) had germ cell tumors (TGCT). Among TGCT, 50% were seminomatous tumors, 48% non-seminomatous tumors (NST) and 2% were spermatocytic seminomas. The NST were further divided into mixed germ cell tumors (63.9%), embryonic carcinomas (18.6%), teratomas (15.4%) and yolk sac tumors (2.1%). The mean age for testicular tumors was 32 years. The mean age for germ cell tumors was 31 years and further subtypes such as seminomatous tumors had a mean age of 34 years, 28 years in non-seminomatous tumors and 56 years in spermatocytic seminoma. Patients with right testicular tumor were the predominant group with 55% of patients. Three patients (1.2%) presented with bilateral tumors.

CONCLUSIONS

The distribution of different subgroups and the mean age for testicular tumors proved comparable to most countries of the world except for some Asian countries. Germ cell tumors are the most common subtype of testicular tumors with seminomatous tumors being slightly more prevalent than non-seminomatous tumors in Lebanese 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.

The rise of testicular germ cell tumours: the search for causes, risk factors and novel therapeutic targets

Since the beginning of the 20th century there has been a decline in the reproductive vitality of men within the Western world. The declining sperm quantity and quality has been associated with increased overt disorders of sexual development including hypospadias, undescended testes and type II testicular germ cell tumours (TGCTs). The increase in TGCTs cannot be accounted for by genetic changes in the population. Therefore exposure to environmental toxicants appears to be a major contributor to the aetiology of TGCTs and men with a genetic predisposition are particularly vulnerable. In particular, Type II TGCTs have been identified to arise from a precursor lesion Carcinoma in situ (CIS), identified as a dysfunctional gonocyte; however, the exact triggers for CIS development are currently unknown. Therefore the transition from gonocytes into spermatogonia is key to those studying TGCTs. Recently we have identified seven miRNA molecules (including members of the miR-290 family and miR-136, 463* and 743a) to be significantly changed over this transition period. These miRNA molecules are predicted to have targets within the CXCR4, PTEN, DHH, RAC and PDGF pathways, all of which have important roles in germ cell migration, proliferation and homing to the spermatogonial stem cell niche. Given the plethora of potential targets affected by each miRNA molecule, subtle changes in miRNA expression could have significant consequences e.g. tumourigenesis. The role of non-traditional oncogenes and tumour suppressors such as miRNA in TGCT is highlighted by the fact that the majority of these tumours express wild type p53, a pivotal tumour suppressor usually inactivated in cancer. While treatment of TGCTs is highly successful, the impact of these treatments on fertility means that identification of exact triggers, earlier diagnosis and alternate treatments are essential. This review examines the genetic factors and possible triggers of type II TGCT to highlight target areas for potential new treatments.

Le cancer du testicule : facteurs de risque génétiques et environnementaux

L'incidence du cancer du testicule (CT), qui est inégale d'une région à l'autre, progresse dans la plupart des pays y compris la France. L'origine la plus probable du CT est la non différenciation de cellules germinales souches pendant la vie fœtale. Ces cellules, maintenues dans un état immature, pourraient proliférer pour former une tumeur après la puberté. La fréquence de son association avec une cryptorchidie ou une infertilité a conduit à formuler l'hypothèse que le CT pouvait être un des constituants du syndrome de dysgénésie testiculaire. Le rôle des facteurs génétiques est suggéré par la fréquence de cas familiaux de CT mais aucun gène clairement responsable du cancer n'a été identifié jusqu'à présent. Parmi les nombreux gènes étudiés, ce sont ceux contrôlant la voie KITLG/KIT, qui participe à la régulation de la prolifération et de la fonction des cellules germinales primordiales, qui semblent jouer le rôle principal. Les études faites sur des populations migrantes et les jumeaux suggèrent par ailleurs que des facteurs environnementaux pourraient jouer un rôle essentiel dans la genèse du CT. Des dérégulations hormonales pendant la vie fœtale ou la puberté pourraient notamment favoriser le développement de CT. Cependant, l'exposition à des substances exogènes agissant comme des perturbateurs endocriniens est encore à démontrer.

APAF-1 is related to an undifferentiated state in the testicular germ cell tumor pathway

Apoptotic protease activating factor-1 (APAF-1) is a key regulator gene of apoptosis, located downstream from p53. Loss of APAF-1 expression is associated with chemorefractory malignant melanoma and neuronal cell differentiation. In order to make clear the function of APAF-1 in the carcinogenesis of germ cell tumors, we evaluated the expression levels of APAF-1 and several apoptosis and differentiation markers by immunohistochemistry in formalin-fixed paraffin-embedded samples from 43 cases of testicular germ cell tumor (TGCT) and six specimens of normal testis tissue. Expression of cleaved caspase-3, Oct-3/4, and Ki-67 were also examined by immunohistochemistry to evaluate apoptotic reactivity, tumor differentiation, and proliferation activity, respectively. APAF-1 was downregulated in two TGCT cell lines by siRNA transfection, and subsequent expression of the Ki-67 and Oct-3/4 genes and differentiation markers of three embryonic germ layers including keratin16 (KRT16) for ectoderm, vimentin (VIM) for mesoderm and GATA4 for endoderm were then tested. No significant relationship was found between APAF-1 expression and apoptotic activity in TGCTs. Expression of APAF-1, Oct-3/4, and Ki-67 was significantly higher in seminomas than in non-seminomas. In TGCTs, higher APAF-1 expression was correlated with higher proliferation (high Ki-67) and a lower degree of differentiation (high Oct-3/4). Interestingly, the expression of APAF-1 gradually decreased in accordance with tumor differentiation (seminoma and embryonal carcinoma > teratoma). Downregulation of APAF-1 in TGCT cell lines resulted in a decrease of Ki-67 and Oct-3/4 and an increase of VIM and KRT16 gene expression. These data show that higher expression of APAF-1 is related to an undifferentiated state in the TGCT pathway.

Testicular cancer risk associated with occupational radiation exposure: a systematic literature review

Testicular cancer is a rare disease, affecting mainly young men aged 15-49. There have been some recent reports that it might be associated with radiation exposure. We have systematically reviewed this topic. English-language articles published between 1990 and 2008 studying the relationship between occupational radiation exposure and testicular cancer were included. Risk of bias was assessed using a modified version of the EPHPP checklist. For ionising radiation we subdivided study populations into occupational groups. No pooled analysis was performed due to the heterogeneity of studies. Seven case-control and 30 cohort studies were included in the review. For radiation workers, one incidence study showed a significant increase and four showed no effect. Eight mortality studies did not indicate an effect while four showed a non-significant increase. Incidence among persons with military exposure was not increased in two studies and non-significantly increased in another two. Among aircrew studies, one showed no effect against five with slight increases. Medical exposure studies showed no increases. For EMF exposure, three studies showed no effect, two reported a significant and four a non-significant increase in incidence. Overall, there was very limited evidence for associations between occupational ionising radiation and testicular cancer, while there were some positive associations for EMF. Testicular cancer mortality is generally low and was not associated with radiation. New incidence studies are recommended to investigate the association between radiation exposure and testicular cancer where exposure is better specified and individually estimated.

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.

GOLPH2 expression may serve as diagnostic marker in seminomas

BACKGROUND

GOLPH2 (Golgi phosphoprotein 2) is a novel Golgi membrane protein. Despite its unknown physiologic function, however, it has been proposed as a biomarker for hepatocellular and prostate carcinoma due to its upregulation in those cancer entities. Whether the overexpression of GOLPH2 is tumour specific or a generic parameter of malignancy and whether this finding is true for additional carcinomas has not been determined. In this study, we aimed to evaluate the expression pattern of GOLPH2 in testicular seminomas, the most common histologic subtype of testicular neoplasm.

METHODS

GOLPH2 protein expression was assessed by immunohistochemistry in 69 testicular seminomas and compared to the expression rates in matching normal testicular tissue and intratubular germ cell neoplasia of unclassified type (IGCNU). In addition, a subset of Leydig cell tumours was analyzed accordingly.

RESULTS

GOLPH2 was consistently overexpressed (89.9%) in seminomas. Matching non-neoplastic tissue showed weak or negative staining. The observed differences between non-neoplastic and neoplastic tissue were statistically highly significant (p < 0.001). There were no significant associations with tumour status. Interestingly, GOLPH2 was also highly expressed in the intertubular Leydig cells as well as in Leydig cell tumours.

CONCLUSIONS

GOLPH2 protein is highly expressed in seminomas and in Leydig cell tumours. This study fosters the association of GOLPH2 with malignant neoplastic processes. The staining pattern is easily assessable and consistent which is a favourable property especially in clinical settings. GOLPH2 could be a novel immunohistochemical marker for the assessment of testicular neoplasms, especially against the background that in analogy to hepatocellular carcinomas complementary GOLPH2 serum levels might be helpful in detecting metastases or recurrent tumour. Therefore serum studies and analyses of GOLPH2 expression in non-seminomatous germ cell tumours are strongly warranted.

Signaling molecules and pathways regulating the fate of spermatogonial stem cells

Spermatogenesis is the process that involves the division and differentiation of spermatogonial stem cells (SSCs) into mature spermatozoa. SSCs are a subpopulation of type A spermatogonia resting on the basement membrane in the mammalian testis. Self-renewal and differentiation of SSCs are the foundation of normal spermatogenesis, and thus a better understanding of molecular mechanisms and signaling pathways in the SSCs is of paramount importance for the regulation of spermatogenesis and may eventually lead to novel targets for male contraception as well as for gene therapy of male infertility and testicular cancer. Uncovering the molecular mechanisms is also of great interest to a better understanding of SSC aging and for developing novel therapeutic strategies for degenerative diseases in view of the recent work demonstrating the pluripotent potential of the SSC. Progress has recently been made in elucidating the signaling molecules and pathways that determine cell fate decisions of SSCs. In this review, we first address the morphological features, phenotypic characteristics, and the potential of SSCs, and then we focus on the recent advances in defining the key signaling molecules and crucial signaling pathways regulating self-renewal and differentiation of SSCs. The association of aberrant expression of signaling molecules and cascades with abnormal spermatogenesis and testicular cancer are also discussed. Finally, we point out potential future directions to pursue in research on signaling pathways of SSCs.

The association risk of male subfertility and testicular cancer: a systematic review

Background

An association between male subfertility and an increased risk of testicular cancer has been proposed, but conflicting results of research on this topic have rendered this theory equivocal. To more precisely assess the association between subfertility and the risk of testicular cancer, we performed a systematic review of international epidemiologic evidence.

Principal Findings

We searched the Medline database for records from January 1966 to March 2008 complemented with manual searches of the literature and then identified studies that met our inclusion criteria. Study design, sample size, exposure to subfertility and risk estimates of testicular cancer incidence were abstracted. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the DerSimonian and Laird model. All statistical tests were two-sided. We identified seven case-control studies and two cohort studies published between 1987 and 2005. Analysis of the seven case-control studies that included 4,954 participants revealed an overall statistically significant association between subfertility and increased risk of testicular cancer (summary RR = 1.68, 95% CI: 1.22 to 2.31), without heterogeneity between studies (Q = 8.46, P heterogeneity = 0.21, I² statistics = 0.29). The association between subfertility and testicular cancer was somewhat stronger in the United States (summary RR = 1.75, 95% CI: 1.01 to 3.02) than it was in Europe (summary RR = 1.53, 95% CI: 1.22 to 1.92). The source of the control subjects had a statistically significant effect on the magnitude of the association (population-based summary—RR = 2.15, 95% CI: 1.11 to 4.17; hospital-based summary—RR = 1.56, 95% CI: 0.93 to 2.61). After excluding possible cryptorchidism, an important confounding factor, we also found a positive association between subfertility and increased risk of testicular cancer (summary RR = 1.59, 95% CI: 1.28 to 1.98). These results were consistent between studies conducted in the United States and in Europe (Q = 0.20, P heterogeneity = 0.66). Of the two cohort studies that reported standardized incidence ratios, both reported a statistically significant positive association between subfertility and increased risk of testicular cancer.

Conclusions

Our findings support a relationship between subfertility and increased risk of testicular cancer and apply to the management of men with subfertility, and prevention and diagnosis of testicular cancer.

Management of the contralateral testicle in patients with unilateral testicular cancer

Patients with a prior history of a germ cell tumor of the testicle are known to have an increased risk of development of a second germ cell tumor in the contralateral testicle. It is believed that all patients who develop a germ cell tumor of the testicle have a precursor lesion know as carcinoma in situ (CIS) or intratubular germ cell neoplasia. Approximately 50% of these patients will subsequently go on to develop a germ cell tumor in the testicle. A biopsy of the contralateral testicle in a patient with a previous history of a germ cell tumor of the testicle has been advocated by some, while others recommend a biopsy only in patients with other risk factors as well. The arguments for biopsy are that intervention may be used to prevent the development of a second germ cell tumor when CIS is detected. In this review we present the arguments for and against a biopsy of the contralateral testicle, review the techniques of biopsy as well as its complications, and discuss the interventions employed to prevent CIS from progressing.