Subfertility increases risk of testicular cancer: evidence from population-based semen samples

Infertile Men Have Higher Prostate-specific Antigen Values than Fertile Individuals of Comparable Age

BACKGROUND

Infertile men are at greater risk for oncological and nononcological chronic disease than fertile individuals.

OBJECTIVE

To investigate prostate-specific antigen (PSA) values in men presenting for primary couple's infertility compared with a cohort of fertile individuals, according to the recommendation of the European Association of Urology guidelines that a first PSA assessment should be done at 40-45 yr of age.

DESIGN, SETTING, AND PARTICIPANTS

This is a cross-sectional study. Data from 956 (90%) infertile men and 102 (9.6%) fertile participants were analysed. Circulating hormones, total PSA, and semen parameters were investigated in every man.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Descriptive statistics, local polynomial smoothing, and linear regression models were used to test potential associations with PSA levels.

RESULTS AND LIMITATIONS

Overall, PSA >1 ng/ml was found in 318 (30%) men. Serum PSA was higher (p = 0.02), while serum testosterone (p < 0.01) was lower in infertile than in fertile men. In participants younger than 40 yr, 176 (27%) men had PSA >1 ng/ml; of them, a greater proportion were infertile (28% infertile vs 17% fertile, p = 0.03). At multivariable linear regression analysis, infertile status (coefficient 0.21; 95% confidence interval 0.02-0.39) was associated with higher PSA values, after adjusting for age and serum testosterone level. This was a single-centre study, raising the possibility of selection biases.

CONCLUSIONS

Infertile men have higher PSA values than fertile individuals. Of all, almost one out of three primary infertile men younger than 40 yr has a first total PSA value of >1 ng/ml.

PATIENT SUMMARY

In this study, we observed that (1) infertile men have higher prostate-specific antigen (PSA) values than fertile individuals and (2) a greater proportion of infertile men younger than 40 yr had total PSA >1 ng/ml at the first assessment. These data might be relevant to study the potential clinical impact of more rigorous screening in primary infertile men.

Association between male infertility and male-specific malignancies: systematic review and meta-analysis of population-based retrospective cohort studies

OBJECTIVE

To investigate the current evidence that correlates impaired male fertility with the risk of developing male-related malignancies.

DESIGN

Systematic review and meta-analysis of population-based retrospective cohort studies.

SETTING

Not applicable.

PATIENT(S)

Men diagnosed with impaired fertility status and subsequently observed to determine incidence risk in developing testicular cancer (TCa) or prostate cancer (PCa).

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Pooled risk ratio (RR) differences among male factor infertility subjects compared with a fertile control population, and meta-regression analysis according to age at baseline, mean follow-up, range of study time, and year of publication.

RESULT(S)

Six studies met the inclusion criteria and were critically examined. Four studies examined male infertility and TCa (n = 161,634; 174 TCa cases), and four examined infertility in relation to PCa (n = 183,950 men; 377 PCa cases) from 1963 to 2014. The pooled RR was 2.033 (95% confidence interval [CI], 1.66-2.48); heterogeneity: Q = 3.04 (degree of freedom [df] = 3); I² = 1.55% for TCa and 1.68 (95% CI, 1.17-2.4); Q = 23.3(df = 3); I² = 87.1% for PCa.

CONCLUSION(S)

Male infertility was associated with a subsequent risk of both TCa and PCa. Although the clinical significance of these findings remains uncertain, future studies should evaluate the underlying mechanisms to determine whether testis and prostate screening practices should be altered in men with male infertility.

CLINICAL TRIAL REGISTRATION NUMBER

PROSPERO 167277.

Clinical correlation among male infertility and overall male health: A systematic review of the literature

Purpose

Ongoing evidence has suggested the role of male factor infertility as a potential predictor of mortality and general health status. The aim of the present review is to update the current knowledge base regarding the association between male factor infertility and general health through a critical review of the literature.

Materials and Methods

A systematic review of the literature was carried out from inception to November 2019 in order to evaluate significant associations between male infertility and adverse health outcomes such as cardiovascular, oncologic, metabolic and autoimmune diseases as well as overall mortality.

Results

In all, 27 studies met inclusion criteria and were critically examined. Five studies examined male infertility and cardiovascular disease risk, 11 examined oncologic risk (e.g., overall cancer risk, testis and prostate cancer), 8 examined aggregate chronic medical diseases and 5 infertility related to incidence of mortality, for a total of 599,807 men diagnosed with any male factor infertility covering a period from 1916 to 2016.

Conclusions

A man's fertility and overall health appear to be interconnected. Therefore, a diagnosis of male infertility may allow a window into future comorbidity and/or mortality which may help guide clinical decisions and counseling. Several possible etiologies such as genetic, epigenetic, developmental, and lifestyle-based factors need to be further evaluated in order to establish the underlying mechanisms between male infertility and health.

Deficiency of the onco-miRNA cluster, miR-106b∼25, causes oligozoospermia and the cooperative action of miR-106b∼25 and miR-17∼92 is required to maintain male fertility

The identification of new genes involved in sexual development and gonadal function as potential candidates causing male infertility is important for both diagnostic and therapeutic purposes. Deficiency of the onco-miRNA cluster miR-17∼92 has been shown to disrupt spermatogenesis, whereas mutations in its paralog cluster, miR-106b∼25, that is expressed in the same cells, were reported to have no effect on testis development and function. The aim of this work is to determine the role of these two miRNA clusters in spermatogenesis and male fertility. For this, we analyzed miR-106b∼25 and miR-17∼92 single and double mouse mutants and compared them to control mice. We found that miR-106b∼25 knock out testes show reduced size, oligozoospermia and altered spermatogenesis. Transcriptomic analysis showed that multiple molecular pathways are deregulated in these mutant testes. Nevertheless, mutant males conserved normal fertility even when early spermatogenesis and other functions were disrupted. In contrast, miR-17∼92+/-; miR-106b∼25-/- double mutants showed severely disrupted testicular histology and significantly reduced fertility. Our results indicate that miR-106b∼25 and miR-17∼92 ensure accurate gene expression levels in the adult testis, keeping them within the required thresholds. They play a crucial role in testis homeostasis and are required to maintain male fertility. Hence, we have identified new candidate genetic factors to be screened in the molecular diagnosis of human males with reproductive disorders. Finally, considering the well-known oncogenic nature of these two clusters and the fact that patients with reduced fertility are more prone to testicular cancer, our results might also help to elucidate the molecular mechanisms linking both pathologies.

The Role of the Urologist in a Reproductive Endocrinology and Infertility Practice

With male factor infertility accounting for up to 50% of infertility cases, demand for male fertility services has increased. Integrating a reproductive urologist within a fertility center allows for treatment of both partners simultaneously with easier, more convenient access to a comprehensive male evaluation and any indicated interventions. A joint practice allows urologists to collaborate more closely with reproductive endocrinologists, which can, in turn, improve clinical care and research endeavors. This full-service, streamlined approach translates to optimized care for the infertile couple and allows for emphasis of male partner health.

Role of genetics and epigenetics in male infertility

Male infertility is a complex condition with a strong genetic and epigenetic background. This review discusses the importance of genetic and epigenetic factors in the pathophysiology of male infertility. The interplay between thousands of genes, the epigenetic control of gene expression, and environmental and lifestyle factors, which influence genetic and epigenetic variants, determines the resulting male infertility phenotype. Currently, karyotyping, Y-chromosome microdeletion screening and CFTR gene mutation tests are routinely performed to investigate a possible genetic aetiology in patients with azoospermia and severe oligozoospermia. However, current testing is limited in its ability to identify a variety of genetic and epigenetic conditions that might be implicated in both idiopathic and unexplained infertility. Several epimutations of imprinting genes and developmental genes have been postulated to be candidate markers for male infertility. As such, development of novel diagnostic panels is essential to change the current landscape with regard to prevention, diagnosis and management. Understanding the underlying genetic mechanisms related to the pathophysiology of male infertility, and the impact of environmental exposures and lifestyle factors on gene expression might aid clinicians in developing individualised treatment strategies.

Male Infertility and Somatic Health

Somatic health is associated with male infertility; potential links between infertility and health may arise from genetic, developmental, and lifestyle factors. Studies have explored possible connections between male infertility and oncologic, cardiovascular, metabolic, chronic, and autoimmune diseases. Male infertility also may be a predictor of hospitalization and mortality. Additional research is required to elucidate the mechanisms by which male infertility affects overall health.

New insights to guide patient care: the bidirectional relationship between male infertility and male health

Male reproduction is a complex process, and numerous medical conditions have the potential to alter spermatogenesis. In addition, male factor infertility may be a biomarker for future health. In the present review, we discuss the current literature regarding the association between systemic diseases and fertility, which may impact clinical outcomes or semen parameters. A number of conditions that have systemic consequences were identified, including genetic (e.g., cystic fibrosis, DNA mismatch repair alterations), obesity, psychological stress, exogenous testosterone, and a variety of common medications. As such, the infertility evaluation may offer an opportunity for health counseling beyond the discussion of reproductive goals. Moreover, male infertility has been suggested as a marker of future health, given that poor semen parameters and a diagnosis of male infertility are associated with an increased risk of hypogonadism, cardiometabolic disease, cancer, and even mortality. Therefore, male fertility requires multidisciplinary expertise for evaluation, treatment, and counseling.

Male Sexual and Reproductive Health-Does the Urologist Have a Role in Addressing Gender Inequality in Life Expectancy?

Despite considerable public health initiatives in the past century, there remains a significant gender inequality in life expectancy. The Global Burden of Diseases study has highlighted that the life expectancy for men is 70.5years, compared with 75.6years for women. This discrepancy in mortality appears to be related to a disproportionately higher number of preventable and premature male deaths. Whilst there has been an increased focus on men's health, as evidenced by the establishment of men's health charities and governmental legislation promoting equality, a recent World Health Organization report has highlighted that there is still a prevailing misconception that the higher rate of premature mortality amongst men is a natural phenomenon. We explore the association of male sexual and reproductive health-related diseases and the potential role of a urologist in addressing gender inequality in life expectancy. PATIENT SUMMARY: In this report, we discuss the causes for the gender gap in life expectancy and highlight that men continue to have a higher rate of premature death than women, which is associated with diseases of the male reproductive system. Furthermore, this not only appears to be related to a number of metabolic and lifestyle factors, but may also be the result of the increased risk of cancer in men with sexual and reproductive health-related diseases.

Risk of prostate cancer for men fathering through assisted reproduction: nationwide population based register study

OBJECTIVE

To compare the risk and severity of prostate cancer between men achieving fatherhood by assisted reproduction and men conceiving naturally.

DESIGN

National register based cohort study.

SETTING

Sweden from January 1994 to December 2014.

PARTICIPANTS

1 181 490 children born alive in Sweden during 1994-2014 to the same number of fathers. Fathers were grouped according to fertility status by mode of conception: 20 618 by in vitro fertilisation (IVF), 14 882 by intra-cytoplasmic sperm injection (ICSI), and 1 145 990 by natural conception.

MAIN OUTCOME MEASURES

Prostate cancer diagnosis, age of onset, and androgen deprivation therapy (serving as proxy for advanced or metastatic malignancy).

RESULTS

Among men achieving fatherhood by IVF, by ICSI, and by non-assisted means, 77 (0.37%), 63 (0.42%), and 3244 (0.28%), respectively, were diagnosed as having prostate cancer. Mean age at onset was 55.9, 55.1, and 57.1 years, respectively. Men who became fathers through assisted reproduction had a statistically significantly increased risk of prostate cancer compared with men who conceived naturally (hazard ratio 1.64, 95% confidence interval 1.25 to 2.15, for ICSI; 1.33, 1.06 to 1.66, for IVF). They also had an increased risk of early onset disease (that is, diagnosis before age 55 years) (hazard ratio 1.86, 1.25 to 2.77, for ICSI; 1.51, 1.09 to 2.08, for IVF). Fathers who conceived through ICSI and developed prostate cancer received androgen deprivation therapy to at least the same extent as the reference group (odds ratio 1.91; P=0.07).

CONCLUSIONS

Men who achieved fatherhood through assisted reproduction techniques, particularly through ICSI, are at increased risk for early onset prostate cancer and thus constitute a risk group in which testing and careful long term follow-up for prostate cancer may be beneficial.

Mechanisms of cisplatin sensitivity and resistance in testicular germ cell tumors

Testicular germ cell tumors (TGCTs) are a cancer pharmacology success story with a majority of patients cured even in the highly advanced and metastatic setting. Successful treatment of TGCTs is primarily due to the exquisite responsiveness of this solid tumor to cisplatin-based therapy. However, a significant percentage of patients are, or become, refractory to cisplatin and die from progressive disease. Mechanisms for both clinical hypersensitivity and resistance have largely remained a mystery despite the promise of applying lessons to the majority of solid tumors that are not curable in the metastatic setting. Recently, this promise has been heightened by the realization that distinct (and perhaps pharmacologically replicable) epigenetic states, rather than fixed genetic alterations, may play dominant roles in not only TGCT etiology and progression but also their curability with conventional chemotherapies. In this review, it discusses potential mechanisms of TGCT cisplatin sensitivity and resistance to conventional chemotherapeutics.

Recent advances in understanding and managing male infertility

Infertility is a prevalent condition affecting an estimated 70 million people globally. The World Health Organization estimates that 9% of couples worldwide struggle with fertility issues and that male factor contributes to 50% of the issues. Male infertility has a variety of causes, ranging from genetic mutations to lifestyle choices to medical illnesses or medications. Recent studies examining DNA fragmentation, capacitation, and advanced paternal age have shed light on previously unknown topics. The role of conventional male reproductive surgeries aimed at improving or addressing male factor infertility, such as varicocelectomy and testicular sperm extraction, have recently been studied in an attempt to expand their narrow indications. Despite advances in the understanding of male infertility, idiopathic sperm abnormalities still account for about 30% of male infertility. With current and future efforts examining the molecular and genetic factors responsible for spermatogenesis and fertilization, we may be better able to understand etiologies of male factor infertility and thus improve outcomes for our patients.

Altered Molecular Pathways in the Proteome of Cryopreserved Sperm in Testicular Cancer Patients before Treatment

Testicular cancer (TC) represents the most common cancer affecting men within the reproductive age and is often accompanied by major disturbances in semen parameters. Cryopreservation is recommended in these patients before initiating cancer treatment. Currently, there are no studies reporting the molecular mechanisms associated with altered semen quality in these men. The main objective of this study was to compare the sperm proteome of normozoospermic (motility >40%) and asthenozoospermic (motility <40%) TC patients with normozoospermic infertile men without cancer (control group). Pooled sperm samples from normozoospermic (n = 20), asthenozoospermic (n = 11) TC, and a control group (n = 9) were used for quantitative global proteomic profiling using liquid chromatography-tandem mass spectrometry. A total of 1085, 846, and 982 proteins were identified in normozoospermic TC, asthenozoospermic TC, and control groups, respectively. Functional analysis revealed mitochondrial dysfunction and altered cellular pathways in both normozoospermic and asthenozoospermic TC patients. Comparison of pathway analysis showed no significant difference in fertility-associated proteins/mechanism between the normozoospermic TC patients and infertile men. Western blot analysis revealed under-expression of NDUFS1 associated with mitochondrial dysfunction and overexpression of CD63 involved in sperm maturation in both normozoospermic and asthenozoospermic TC patients. Our proteomic results confirm that defective cellular pathways are associated with reproductive functions in both normozoospermic and asthenozoospermic TC patients before the start of cancer treatment.

Urologic conditions associated with malignancy

INTRODUCTION

Recent advances in cancer research have highlighted the role of genetics in malignancy. Genetic dysregulation of core cellular functions similarly influences benign conditions. These common genetic factors have led researchers to identify an association between certain urologic conditions and malignancy. The objective of this review is to evaluate the literature linking benign urologic conditions including male infertility, Peyronie's disease, cryptorchidism, and hypospadias, to malignancy.

METHODS

A search of PubMed was performed using the following search terms and their combinations: male infertility, female infertility, cancer, malignancy, mortality, male urologic conditions, azoospermia, Peyronie's disease, cryptorchidism, hypospadias, and genetics. Studies were assessed for quality and included or excluded based on study design and relevance to the topic of urologic conditions and malignancy.

RESULTS

A total of 52 studies were evaluated, of which 38 were included. Associations between male infertility and testicular cancer, prostate cancer, and other cancers including melanoma, bladder cancer, and thyroid cancer were examined. Several genetic alterations were found to be common in the pathogenesis of both male infertility and carcinogenesis. Associations between female infertility and breast, ovarian, and endometrial cancer are also assessed, as are the relationships between Peyronie's disease, cryptorchidism, and hypospadias and malignancy.

CONCLUSIONS

Recent work has identified associations between a number of malignancies and benign urologic conditions including male infertility, Peyronie's disease, cryptorchidism, and hypospadias. Molecular and genetic mechanisms have been proposed, but no definitive causal relationships have been identified to date. Future work will continue to better define the links between malignancy and benign urologic conditions and ultimately facilitate risk stratification, screening, and treatment of affected men.

A 10-year prospective study of personality and reproductive success: Testing the mediating role of healthy living

OBJECTIVE

There is some evidence that personality relates to childbearing in adulthood but the importance of personality for reproductive capacity is unknown. This study explored cross-time associations between the major dimensions of trait personality and self-reported fertility and fecundity.

METHODS

A representative sample of young Australian adults [n = 4501; age range ≈ 18-44 (women), 18-54 (men)] provided information on personality, fertility, fertility intentions, fecundity and lifestyle factors (cigarette smoking, alcohol consumption, physical activity) in 2006 and again in 2016. Older Australian adults [n = 4359; age ≥ 45 (women), ≥ 55 (men)] provided information on personality, lifestyle factors and completed fertility.

RESULTS

After controlling for sociodemographic factors, completed fertility was associated with higher agreeableness in both sexes, and lower conscientiousness and openness in women. In younger adults, higher levels of openness were associated with fewer children 10 years later in both sexes, and higher extraversion was associated with more children 10 years later in men. The association between fertility intentions and subsequent fertility was stronger among women scoring higher on conscientiousness, and women scoring higher on neuroticism were more likely to acquire medical or health difficulties in having children - an effect that was mediated by higher levels of cigarette smoking.

CONCLUSIONS

The study provides initial evidence for an association between personality and the acquisition of difficulties in having children.

Testicular Cancer in Infertile Men With and Without Testicular Microlithiasis: A Systematic Review and Meta-Analysis of Case-Control Studies

Background: An association between testicular microlithiasis (TM) and both carcinoma in situ (CIS) of the testis and testicular germ cell tumors (TGCTs) has been reported. Furthermore, TM seems to be significantly more prevalent in men with male-factor infertility, representing itself a risk factor for TGCT. Nevertheless, the evidence of the association of TM with a higher prevalence of testicular cancer in infertile men remains inconclusive. The aim of this study was to systematically evaluate whether, and to what extent, TM is associated to a significantly higher prevalence of testicular cancer in infertile males. Methods: A thorough search of MEDLINE, SCOPUS, CINAHL, WEB OF SCIENCE, and Cochrane Library databases was carried out to identify case-control studies comparing the prevalence of testicular cancer in infertile men with and without TM. Methodological quality of the studies was assessed using the Newcastle-Ottawa Scale. In the absence of heterogeneity, odds ratios (ORs) with 95% confidence intervals (CIs) for testicular cancer were combined using a fixed effect model. Funnel plots and trim-and-fill analysis were used to assess publication bias. Results: Eight studies met the inclusion criteria and provided information on 180 infertile men with TM and 5,088 infertile men without TM. The pooled OR indicated that the presence of TM is associated with a ~18-fold higher odd for testicular cancer (pooled OR:18.11, 95%CI: 8.09, 40.55; P < 0.0001). No heterogeneity among the studies was observed (P _{for heterogeneity} = 0.99, I ² = 0%). At the sensitivity analysis, similar pooled ORs and 95%CIs were generated with the exclusion of each study, indicating the high degree of stability of the results. The funnel plot revealed a possible publication bias and the trim-and-fill test detected two putative missing studies. Nevertheless, even when the pooled estimate was adjusted for publication bias, there was a still significantly higher odd for testicular cancer in the TM group (adjusted pooled OR: 16.42, 95%CI: 7.62, 35.37; P < 0.0001). Conclusions: In infertile men the presence of TM is associated to an ~18-fold higher prevalence of testicular cancer. Longitudinal studies are warranted to elucidate whether this cross-sectional association actually reflects a higher susceptibility of infertile men with TM to develop testicular cancer over time.

Genetic intersection of male infertility and cancer

Recent epidemiological studies have identified an association between male factor infertility and increased cancer risk, however, the underlying etiology for the shared risk has not been investigated. It is likely that much of the association between the two disease states can be attributed to underlying genetic lesions. In this article we review the reported associations between cancer and spermatogenic defects, and through database searches we identify candidate genes and gene classes that could explain some of the observed shared genetic risk. We discuss the importance of fully characterizing the genetic basis for the relationship between cancer and male factor infertility and propose future studies to that end.

Epigenetics, infertility, and cancer: future directions

Although direct correlates between cancer and infertile epigenetic profiles are rare, the general similarities between the two disease processes offer insights into the study of both abnormalities. Foremost among them is the nature of these pathologies, where one disease (cancer) is categorized by an inability to control or inhibit cellular proliferation, and the other (male infertility) is caused by an inability to maintain the normally efficient extreme proliferation of the male germ cell. Based on this similarity alone, the study of epigenetics in both male fertility and cancer has the potential to offer intriguing insights in both fields. The creative application of harmonious studies of both infertility and cancer is likely to yield useful and informative data that may aid in both the understanding and treatment of both pathologies.

Limitations and opportunities in male fertility databases

Over the last several years, the male component of reproduction has begun to gain clinical momentum. The medical literature has traditionally focused on infertility from the female perspective, but recent publications have demonstrated that male infertility is an important marker of overall health for infertile men as well as their family members. In order to perform large-scale, quality research related to male infertility, comprehensive databases are necessary. Currently, research in male infertility is limited by the fact that there is not a centralized, comprehensive database specifically designed to collect patient information related to male fertility. A database of this nature exists for female infertility research in the form of the Society for Assisted Reproductive Technology (SART) clinical summary report and the National ART Surveillance System (NASS) published by the Centers for Disease Control (CDC). This review outlines the strengths and weaknesses of several male fertility data sources, including the National Survey of Family Growth, the Reproductive Medicine Network, the Andrology Research Consortium (ARC), the Truven Health MarketScan^® databases, the Utah Population Database, and data available from the Ober Lab related to the Hutterites. While each of these sources has been instrumental in the creation of meaningful research within the field of male fertility, a need remains for the creation of a centralized database for use in future male fertility research. The ideal database would consist of vast amounts of patient data which link individuals and couples to biologic specimens as well as data from family members, designed with parameters specifically purposed for male fertility research. The use of electronic medical records (EMR) systems such as Epic may play a role in the development of such a database going forward. At present, although some information is available through current databases, researchers must utilize suboptimal data sources to perform studies.

Do paternal semen parameters influence the birth weight or BMI of the offspring? A study from the Utah Population Database

PURPOSE

To study the role of individual semen parameters on the offspring birth weight and body mass index (BMI) from a population of men evaluated in an assisted reproduction technology (ART) clinic compared to fertile controls.

METHODS

We performed a retrospective study using a cohort with fertile, age-matched controls of men evaluated with semen analysis at the University of Utah Andrology Clinic from 1996 to 2011 and Intermountain Healthcare from 2002 to 2011. We use the offspring from both our sub-fertile cohort and controls using the Utah Population Database. The two main outcomes of interest were offspring birth weight and adolescent BMI.

RESULTS

The offspring of men with impaired sperm parameters had significantly lower birth weight compared to fertile control offspring. Low-concentration offspring weighed 158 g less (95% CI - 278~- 38; p = 0.01), low total count weighed 172 g less (95% CI - 294~- 51; p = 0.005), and low total motility weighed 155 g less (95% CI - 241~- 69; p < 0.001) compared to those of the controls. When we controlled for the use of ART within the sub-fertile group, we found that there was a significant trend of increasing birth weight across levels of total motile count and total sperm count compared to the azoospermic group. We did not find any consistent significant differences between the subject and control adolescence BMI based on semen parameters.

CONCLUSIONS

Despite limitations within our population-based dataset, we found that poor quality semen analysis parameters pointed towards an association with low birth weight in the offspring of sub-fertile men compared to the offspring of normal fertile controls. However, in contrast to studies of ART effects on offspring, we did not find evidence of long-term associations between semen quality and offspring BMI.

Is human fecundity changing? A discussion of research and data gaps precluding us from having an answer

Fecundity, the biologic capacity to reproduce, is essential for the health of individuals and is, therefore, fundamental for understanding human health at the population level. Given the absence of a population (bio)marker, fecundity is assessed indirectly by various individual-based (e.g. semen quality, ovulation) or couple-based (e.g. time-to-pregnancy) endpoints. Population monitoring of fecundity is challenging, and often defaults to relying on rates of births (fertility) or adverse outcomes such as genitourinary malformations and reproductive site cancers. In light of reported declines in semen quality and fertility rates in some global regions among other changes, the question as to whether human fecundity is changing needs investigation. We review existing data and novel methodological approaches aimed at answering this question from a transdisciplinary perspective. The existing literature is insufficient for answering this question; we provide an overview of currently available resources and novel methods suitable for delineating temporal patterns in human fecundity in future research.

Parental health status and infant outcomes: Upstate KIDS Study

OBJECTIVE

To assess parental health status inclusive of infertility and infant outcomes.

DESIGN

Birth cohort with cross-sectional analysis of parental health status and infant outcomes.

SETTING

Not applicable.

PATIENT(S)

Parents (n = 4,886) and infants (n = 5,845) participating in the Upstate KIDS birth cohort.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Infertility was defined as [1] sexually active without contraception for 1+ years without pregnancy, [2] ever requiring ≥12 months to become pregnant, and [3] requiring ≥12 months for index pregnancy. Multivariable linear regression with generalized estimating equations estimated the change (β coefficient and 95% confidence interval [CI]) in infant outcomes (gestation, birthweight, length, head circumference, ponderal index) and relative to each disease, including infertility after adjusting for age, body mass index, and infertility treatment.

RESULT(S)

Prevalence of parental chronic diseases ranged from <1% to 19%, and 21% to 54% for infertility. Maternal hypertension was negatively associated with gestation (β, -0.64; 95% CI, -1.03, -0.25) and birthweight (-151.98; -262.30, -41.67) as was asthma and birthweight (-75.01; -130.40, -19.62). Maternal kidney disease was associated with smaller head circumference (-1.09; -2.17, -0.01), whereas paternal autoimmune disease was associated with larger head circumference (0.87; 0.15, 1.60). Infertility was negatively associated with birthweight (-62.18; -103.78, -20.58), length (-0.33; -0.60, -0.06), and head circumference (-0.35; -0.67, -0.03).

CONCLUSION(S)

Infertility was significantly associated with reduced infant size even after accounting for infertility treatment, although the magnitude of reduction varied by definition of infertility. Absence of pregnancy within a year of being at risk may be informative about health.

Childhood Cancer Risk in the Siblings and Cousins of Men with Poor Semen Quality

PURPOSE

Poor semen quality is associated with reduced somatic health and increased cancer risk. Infertility and cancer are increasingly being linked by epidemiologists and basic scientists. We sought to identify semen parameters associated with an increased childhood cancer risk in the family members of subfertile men.

MATERIALS AND METHODS

We performed a retrospective cohort study in men from the SHARE (Subfertility Heath and Assisted Reproduction) study who underwent semen analysis between 1994 and 2011. We used fertile population controls from the Utah Population Data Base. Our primary outcome was the risk of any childhood (18 years or younger) cancer in the siblings and cousins of men who underwent semen analysis compared to fertile, age matched controls. Cox proportional hazard regression models were used to test the association between semen quality and childhood cancer incidence.

RESULTS

We selected 10,511 men with complete semen analysis and an equal number of fertile controls. These men had a total of 63,891 siblings and 327,753 cousins. A total of 170 and 958 childhood cancers were identified in siblings and cousins, respectively. The 3 most common cancers diagnosed in siblings were acute lymphoblastic leukemia in 37, brain cancer in 35 and Hodgkin lymphoma in 15. Oligozoospermia was associated with a twofold increased risk of any childhood cancer and a threefold increased risk of acute lymphoblastic leukemia in the siblings of subfertile men compared to fertile controls (HR 2.09, 95% CI 1.18-3.69 vs HR 3.07, 95% CI 1.11-8.46).

CONCLUSIONS

Siblings of men with oligozoospermia are at increased risk for any-site cancer and acute lymphoblastic leukemia. This suggests a shared genetic/epigenetic insult or an environmental exposure that merits further investigation.

Subfertility and Risk of Testicular Cancer in the EPSAM Case-Control Study

Background/objectives

It has been suggested that subfertility and testicular cancer share genetic and environmental risk factors. We studied both subfertility and the strongest known testicular cancer susceptibility gene, the c-KIT ligand (KITLG), whose pathway is involved in spermatogenesis.

Methods

The EPSAM case-control study is comprised of testicular cancer patients from the Province of Turin, Italy, diagnosed between 1997 and 2008. The present analysis included 245 cases and 436 controls from EPSAM, who were aged 20 years or older at diagnosis/recruitment. The EPSAM questionnaire collected information on factors such as number of children, age at first attempt to conceive, duration of attempt to conceive, use of assisted reproduction techniques, physician-assigned diagnosis of infertility, number of siblings, and self-reported cryptorchidism. Genotyping of the KITLG single nucleotide polymorphism (SNP) rs995030 was performed on the saliva samples of 202 cases and 329 controls.

Results

Testicular cancer was associated with the number of children fathered 5 years before diagnosis (odds ratio (OR) per additional child: 0.78, 95% confidence interval (CI): 0.58–1.04) and sibship size (OR per additional sibling: 0.76, 95% CI: 0.66–0.88). When considering the reproductive history until 1 year before diagnosis, attempting to conceive for at least 12 months or fathering a child using assisted reproduction techniques was not associated with the risk of testicular cancer, nor was age at first attempt to conceive or physician-assigned diagnosis of infertility. The SNP rs995030 was strongly associated with risk of testicular cancer (per allele OR: 1.83; 95%CI: 1.26–2.64), but it did not modify the association between number of children and the risk of testicular cancer.

Conclusion

This study supports the repeatedly reported inverse association between number of children and risk of testicular cancer, but it does not find evidence of an association for other indicators of subfertility.

Risk of childhood mortality in family members of men with poor semen quality

STUDY QUESTION

What is the familial childhood mortality in first-degree (FDR) and second-degree relatives (SDR) of patients undergoing semen analysis (SA)?

SUMMARY ANSWER

The relationship between infertility and congenital malformations (CM) in offspring is complex, with an increased risk of death due to CM in FDR, but not SDR, of men with lower semen parameters.

WHAT IS KNOWN ALREADY

Semen quality is an established predictor of men's somatic health. We can gain a better understanding of possible genetic or environmental determinants of the infertility phenotype by exploring familial aggregation of childhood mortality in relatives of men with poor semen quality.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study from the Subfertility, Health and Assisted Reproduction study (cohort compiled 1996-2011) linked with patient/familial information from the Utah Population Database (UPDB). Index cases included a clinic-referred sample of 12 889 men who underwent SA and had adequate familial and follow-up data in the UPDB. Parameters of semen quality included: semen concentration, sperm count, motility, total motile count, sperm head morphology, sperm tail morphology and vitality.

PARTICIPANTS/MATERIALS, SETTING, METHODS

SA data were collected from two tertiary medical center andrology laboratories that have captured ~90% of all SA performed in Utah since 2004. Age- and sex-matched fertile controls were selected to create the comparison group for determining risk of childhood death (to age 20 years) in family members. A total of 79 750 siblings and 160 016 aunts/uncles were used to investigate the familial aggregation of childhood mortality. The main outcome was childhood mortality in FDR and SDR of men with SA and their matched controls. All-cause and cause-specific Cox proportional hazard models were used to test the association between semen quality and childhood mortality in family members. Cause-specific models were considered for cancer and CM.

MAIN RESULTS AND THE ROLE OF CHANCE

In the cohort of men with SA, there were 406 (1.0%) deaths in FDR and 772 (1.1%) deaths in SDR due to any cause. There was no significant difference in the risk of all-cause childhood mortality between the relatives of men with SA and the fertile control group [hazard ratio (HR)_Female = 1.08, 95% CI = 0.88, 1.32; HR_Male = 0.88, 95% CI = 0.75, 1.04]. We found no association between semen quality and risk for childhood cancer mortality in FDR or SDR (HR_FDR = 0.98, 95% CI = 0.62, 1.54; HR_SDR = 1.12, 95% CI = 0.83, 1.50). The FDR of men with SA and fertile controls were followed on average for 19.71 and 19.73 years, respectively. During this period of follow-up, FDR of men with SA had an unadjusted 40% relative risk of increased CM-related death. After stratifying by semen parameters and adjusting for birth year, we found FDR of men with worse semen quality, and notably azoospermic men (HR = 2.69, 95% CI = 1.24,5.84), were at higher risk of CM-related death.

LIMITATIONS REASONS FOR CAUTION

A large proportion of men with SA in the study had normal semen parameters. It is important to note that these men themselves may not be subfertile, but they were subfertile at the couple level (i.e. the female partner may be infertile). In addition, care is needed when interpreting our results, as we do not have semen measures on our sample of fertile men. Second, we were unable to include potential confounders such as medical comorbidities, smoking status, or environmental exposures. Third, men with SA were seen at the University of Utah or Intermountain Health Care clinics for a fertility evaluation thereby suggesting a more select population. Fourth, we chose to categorize morphology into equally distributed quartiles as a response to the fact that the World Health Organization threshold for normal motility changed multiple times during our study period. Lastly, we do not know the proportion of female partners with diagnosed infertility. We chose not to subcategorize each infertile male by infertile diagnosis because our goal was to understand how semen parameters influenced familial childhood mortality.

WIDER IMPLICATIONS OF THE FINDINGS

We are not the first study to show a relationship between fertility and CMs. Children conceived through ART may be at higher risk of birth defects, however it is not known if the relationship is causal or if there is some underlying factor linking infertility and birth outcomes. This study provides further evidence that the increased risk of congenital birth defects may not be due to the ART, but rather genetic or environmental factors that link the two outcomes. We encourage further research in order to confirm a relationship between semen quality and increased risk for CM.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Institutes of Health - National Institute of Aging [Grant numbers 1R21AG036938-01, 2R01 AG022095 and 1K12HD085852-01]. Authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

Not applicable.

Leydig cell tumor found incidentally during microscopic testicular sperm extraction in patient with mosaic Klinefelter syndrome: case report

OBJECTIVE

To report the finding and management of a case of Leydig cell tumor discovered during the infertility evaluation of a patient with mosaic Klinefelter syndrome.

DESIGN

Single case report.

SETTING

Academic hospital.

PATIENT(S)

Patient seeking assistance with fertility after a diagnosis of mosaic Klinefelter syndrome.

INTERVENTION(S)

The patient underwent microscopic testicular sperm extraction (mTESE) for sperm identification after the diagnosis of mosaic Klinefelter syndrome. Abnormal testicular tissue was identified during mTESE and histologically confirmed to be a Leydig cell tumor. The patient was informed of this incidental discovery and later underwent orchiectomy for conservative oncologic control.

MAIN OUTCOME MEASURE(S)

Histologic testicular assessment.

RESULT(S)

Patient was found to have no viable sperm on mTESE, but achieved oncologic control with bilateral orchiectomy.

CONCLUSION(S)

The presented case emphasizes the importance of awareness and expedient appropriate management to achieve oncologic control of a rare tumor with low malignant potential discovered during otherwise routine mTESE. In particular, it highlights the role of the infertility specialist in aiding in diagnosis and treatment of incidental and rare findings.