Fatherhood status and prostate cancer risk

Health-Related and Psychosocial Factors Associated with Prostate Cancer Stage at Diagnosis among Males Participating in Alberta's Tomorrow Project

Prostate cancer (PCa) stage at diagnosis is an important predictor of cancer prognosis. In Canada, over one-quarter of males are diagnosed with advanced-stage PCa. Studies have identified several factors associated with PCa stage at diagnosis; however, evidence from Canada is limited. This study aimed to examine associations between sociodemographic characteristics, health history, health practices, and psychosocial factors and PCa stage at diagnosis among males participating in Alberta's Tomorrow Project (ATP), a prospective cohort in Alberta, Canada. The study included males aged 35-69 years who developed PCa until January 2018. Factors associated with PCa stage at diagnosis were examined using partial proportional odds (PPO) ordinal regression models. A total of 410 males were diagnosed with PCa over the study period. A higher number of lifetime prostate-specific antigen tests were associated with earlier-stage PCa (OR 0.91, p = 0.02, 95% CI 0.83-0.99), while higher abdominal circumference (OR 1.02, p = 0.05, 95% CI 1.00-1.03), lower social support (OR 2.34, p < 0.01, 95% CI 1.31-4.17), and having children (OR 2.67, p < 0.01, 95% CI 1.38-5.16) were associated with later-stage disease. This study identified factors previously found in the literature as well as novel factors associated with PCa stage at diagnosis, which can help inform targets for cancer prevention programs to improve PCa prognosis.

Unlocking the mystery associated with infertility and prostate cancer: an update

Male-specific reproductive disorders and cancers have increased intensely in recent years, making them a significant public health problem. Prostate cancer (PC) is the most often diagnosed cancer in men and is one of the leading causes of cancer-related mortality. Both genetic and epigenetic modifications contribute to the development and progression of PC, even though the exact underlying processes causing this disease have yet to be identified. Male infertility is also a complex and poorly understood phenomenon believed to afflict a significant portion of the male population. Chromosomal abnormalities, compromised DNA repair systems, and Y chromosome alterations are just a few of the proposed explanations. It is becoming widely accepted that infertility shares a link with PC. Much of the link between infertility and PC is probably attributable to common genetic defects. This article provides an overview of PC and spermatogenic abnormalities. This study also investigates the link between male infertility and PC and uncovers the underlying reasons, risk factors, and biological mechanisms contributing to this association.

Association between male infertility and prostate cancer: a systematic review and meta-analysis

PURPOSE OF REVIEW

Male infertility has been shown to be associated with different maladies. The present systematic review and meta-analysis aimed to summarize the available evidence on the association between male infertility or childlessness and prostate cancer.

RECENT FINDINGS

The PubMed, Web of Science, and Scopus databases were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Studies were deemed eligible if they compared males with known infertility or childlessness to the control group including fertile males with regards to the diagnosis of prostate cancer. Overall, ten studies met our eligibility criteria. Three studies found that infertility was associated with higher risk of prostate cancer, four studies - with a reduced risk of prostate cancer, and three studies found no association. The forest plot revealed that infertility was not associated with prostate cancer (odds ratio [OR]: 1.26, 95% confidence interval [CI] 0.63-2.54; P = 0.5). Infertility was not associated with high (OR: 1.44, 95% CI 0.54-3.83; P = 0.5) or low (OR: 0.99, 95% CI 0.43-2.27; P = 0.9) grade prostate cancer.

SUMMARY

Infertility or childlessness were not associated with the risk of prostate cancer. The significant heterogeneity between the included studies supports the need for more granular research to guide/fine tune early detection guidelines based on fertility.

Vasectomy and Prostate Cancer Risk: A 38-Year Nationwide Cohort Study

BACKGROUND

A man's risk of prostate cancer has been linked to his prior reproductive history, with low sperm quality, low ejaculation frequency, and a low number of offspring being associated with increased prostate cancer risk. It is, however, highly controversial whether vasectomy, a common sterilization procedure for men, influences prostate cancer risk.

METHODS

We established a cohort of all Danish men (born between 1937 and 1996) and linked information on vasectomy, doctor visits, socioeconomic factors, and cancer from nationwide registries using unique personal identification numbers. Incidence risk ratios for prostate cancer by time since vasectomy and age at vasectomy during the follow-up were estimated using log-linear Poisson regression.

RESULTS

Overall, 26 238 cases of prostate cancer occurred among 2 150 162 Danish men during 53.4 million person-years of follow-up. Overall, vasectomized men had an increased risk of prostate cancer compared with nonvasectomized men (relative risk = 1.15, 95% confidence interval = 1.10 to 1.20). The increased risk of prostate cancer following vasectomy persisted for at least 30 years after the procedure and was observed regardless of age at vasectomy and cancer stage at diagnosis. Adjustment for the number of visits to the doctor and socioeconomic factors did not explain the association.

CONCLUSIONS

Vasectomy is associated with a statistically significantly increased long-term risk of prostate cancer. The absolute increased risk following vasectomy is nevertheless small, but our finding supports a relationship between reproductive factors and prostate cancer risk.

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.

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.

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.

Reduced risk of prostate cancer in childless men as compared to fathers: a systematic review and meta-analysis

The previously reported association between fatherhood status and prostate cancer risk was controversial. We carried out the present meta-analysis of all relevant studies to summarize evidence on this association. A comprehensive literature search of studies was performed in PubMed, Web of Science, and the Chinese National Knowledge Infrastructure (CNKI) databases, covering all the papers published from their inception to September 2015. The combined risk estimates with 95% confidence intervals (CIs) were calculated using a random effects model. Heterogeneity and publication bias were also evaluated. A total of 11 studies were finally included in this meta-analysis. We found a significantly reduced risk of prostate cancer associated with being childless (OR 0.91, 95% CI 0.87–0.96). There was statistically significant heterogeneity across the studies (P < 0.001, I² = 88.2%). In summary, this meta-analysis supports that being fatherless is associated with a lower risk of prostate cancer. Because of the substantial heterogeneity and residual confounding, using other study designs to further explore this association and the underling mechanism is warranted.

Male reproductive cancers and infertility: a mutual relationship

Reproductive dysfunction and malignancies related to the male gender represent a serious health concern, whose incidence has significantly risen over the past years. Prior to treatment, testicular or prostate cancer patients often display poor semen characteristics similar to subfertile or infertile patients. This fact is underscored by cases where the malignancy is often diagnosed in males who undergo a general fertility screening. This review aims to examine the associations between male infertility and reproductive cancers focusing on common etiologies and biological mechanisms underlining these pathologies. Furthermore, we discuss compelling epidemiological data hypothesizing that male reproductive failure may act as a precursor of future andrological malignancies, including testicular or prostate cancer, thus providing a stimulus for a more specific research in male reproductive health and emphasizing the importance of this relation for physicians taking care of male patients with a reproductive disease.

Fathering of dizygotic twins and risk of prostate cancer: nationwide, population-based case-control study

BACKGROUND

An association between male fertility and risk of prostate cancer has been suggested, possibly through lower androgen levels in subfertile men. We evaluated male fertility in relation to risk of prostate cancer by assessing the frequency of fathering of dizygotic twins, a marker of high fertility, among cases of prostate cancer and controls.

METHODS

We performed a case-control study in Prostate Cancer data Base Sweden (PCBaSe), a nationwide, population-based cohort. PCBaSe was linked to the Swedish twin register for information on zygosity for same-sex twins and to other nationwide health care registers and demographic databases for information on socioeconomic factors, comorbidity, and tumor characteristics for 96 301 prostate cancer cases and 378 583 matched controls. To account for the influence of in vitro fertilization on dizygotic twinning, analyses were restricted to men who had fathered children before 1991, when in vitro fertilization was still uncommon in Sweden.

RESULTS

1 112 cases and 4 538 controls had fathered dizygotic twins. Men with dizygotic twins had no increased risk of prostate cancer compared to fathers of singletons; neither for total prostate cancer odds ratio (OR) 0.95(95% CI 0.89-1.02), nor for any risk category, OR 0.97 (95% CI 0.84-1.12) for low-risk disease, and OR 1.04 (95% CI 0.90-1.22) for metastatic disease.

CONCLUSION

The lack of association between fathering of dizygotic twins and prostate cancer risk give no support for an association between male fertility and prostate cancer risk.

Fatherhood status and risk of prostate cancer: nationwide, population-based case-control study

Previous studies have shown a decreased risk of prostate cancer for childless men; however, the cause of the association remains to be elucidated. The aim of our study was to assess the risk of prostate cancer by fatherhood status, also considering potential confounding factors. In a case-control study in Prostate Cancer data Base Sweden 2.0, a nationwide, population-based cohort, data on number of children, marital status, education, comorbidity and tumor characteristics obtained through nationwide healthcare registers and demographic databases for 117,328 prostate cancer cases and 562,644 controls, matched on birth year and county of residence, were analyzed. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for prostate cancer overall and by risk category, adjusting for marital status and education. Childless men had a decreased risk of prostate cancer compared to fathers, OR = 0.83 (95% CI = 0.82-0.84), and risk was lower for low-risk prostate cancer, OR = 0.74 (95% CI = 0.72-0.77), than for metastatic prostate cancer, OR = 0.93 (95% CI = 0.90-0.97). Adjustment for marital status and education attenuated the association in the low-risk category, adjusted OR = 0.87 (95% CI = 0.84-0.91), whereas OR for metastatic cancer remained virtually unchanged, adjusted OR = 0.92 (95% CI = 0.88-0.96). Our data indicate that the association between fatherhood status and prostate cancer to a large part is due to socioeconomic factors influencing healthcare-seeking behavior including testing of prostate-specific antigen levels.

Emerging evidence for the role of genomic instability in male factor infertility

Male infertility is a common and complex pathology affecting about 7% of men of reproductive age. Given its complexity, the underlying etiology for male infertility is often unknown. A growing amount of evidence suggests genomic instability may be an important factor in some cases of male factor infertility. While some specific manifestations of genomic instability, such as increased sperm aneuploidy rates and increased somatic translocations and inversions in infertile men, are well established, other facets of genomic instability associated with male infertility have not been thoroughly investigated. A limited body of recent work has identified a potential association between microsatellite instability and spermatogenic failure. In addition, mutations in mismatch repair and tumor suppressor genes, which could potentially lead to genomic instability, have been identified in some infertile men and animal models. In addition, results of two epidemiologic studies suggest spermatogenic defects might be just one aspect of a more systemic problem, possibly due to increased genomic instability. In this review we discuss well-established links between genomic instability and male infertility, as well as some of the emerging but less established data to support this relationship. We also propose some important areas of future research toward a more complete understanding of the underlying mechanisms for male infertility.

Male reproductive health and prostate cancer risk

PURPOSE OF REVIEW

Male infertility impacts a substantial proportion of men and has serious implication for a man's quality of life. Advances in reproductive technology may allow men to bypass urologic care in order to achieve their family planning goals. Recent data suggests that male reproductive failure may be a harbinger of future urologic diseases, including prostate cancer (CaP), thus emphasizing the importance of dedicated urologic evaluation and care for all male infertility patients.

RECENT FINDINGS

We will review the epidemiologic data that explores an association between male reproductive health and CaP. We will review the potential biologic mechanisms that may underlie this association, and explore possible reasons for inconsistencies in study findings.

SUMMARY

Studies of the association between male infertility and CaP are inconsistent. Despite this, the association between reproductive health in a man's fourth decade (30s) and his development of aggressive CaP in his sixth decade (50s) should not be ignored. These findings, combined with the robustness of the potential common underlying mechanisms, provide a foundation for future studies of male reproductive health that are more specific in their approach to answering questions about the association between male reproductive failure and future systemic disease.

Fatherhood and the risk of cardiovascular mortality in the NIH-AARP Diet and Health Study

BACKGROUND

Fertility potential and reproductive fitness may reflect a man's future health, given that over one-third of the male human genome is involved in reproduction. We sought to determine if offspring number predicts cardiovascular death in the US men.

METHODS

Using data from the NIH-AARP Diet and Health Study, 137,903 men (aged 50-71) without prior cardiovascular disease were followed-up for an average of 10.2 years. International Classification of Diseases, ninth edition, codes were used to establish the cause of death, and multivariable Cox proportional hazards modeling was used to estimate the association between offspring number and cardiovascular death while accounting for sociodemographic and lifestyle characteristics.

RESULTS

Almost all (92%) participants had fathered at least one child and 50% had three or more offspring. A total of 3082 men died of cardiovascular causes during follow-up for an age-adjusted incidence rate of 2.70 per 1000 person-years. Compared with fathers, after adjusting for sociodemographic and lifestyle factors, childless men had a 17% [hazard ratio (HR): 1.17; 95% confidence interval (CI): 1.03-1.32] increased risk of death from cardiovascular disease contracted in the study period, and this elevated risk appeared to extend also to men with only one child. In comparison with fathers of five or more children, adjusted relative hazards for cardiovascular mortality of this sort were 1.06 (95% CI: 0.92-1.22) for four children, 1.02 (0.90-1.16) for three children, 1.02 (0.90-1.16) for two children, 1.11 (0.95-1.30) for one child and 1.21 (1.03-1.41) for no children.

CONCLUSIONS

Married men who have no children have a higher risk of dying from cardiovascular disease contracted after the age of 50 than men with two or more children.

[Informations for the infertile couple]

The aim of the first consultation related to infertility is supposed to be the optimization of all factors that can increase the chances of pregnancy: more frequent sexual intercourse during the fertility windows; lifestyle modifications (better diet, decreased exposure to tobacco or other toxics); older couples can enjoy the same advice but should be proposed a quicker medical support. Maternal preconceptional advice must be transmitted. A testicular cancer must always be excluded in infertile men, while the risk of hormone-dependent cancers in infertile women remains undetermined. With the results of this first consultation, couples will generally be proposed the best solution to achieve their parental project: ovarian stimulation assisted reproductive technology (IUI, IVF or ICSI) or adoption.

Fatherhood and incident prostate cancer in a prospective US cohort

BACKGROUND

Fatherhood status has been hypothesized to affect prostate cancer risk but the current evidence is limited and contradictory.

METHODS

We prospectively evaluated the relationship between offspring number and the risk of prostate cancer in 161,823 men enrolled in the National Institues of Health - American Association of Retired Persons Diet and Health Study. Participants were aged 50-71 years without a cancer diagnosis at baseline in 1995. Analysing 8134 cases of prostate cancer, Cox regression was used to estimate the association between offspring number and prostate cancer incidence while accounting for socio-demographic and lifestyle characteristics.

RESULTS

When examining the entire cohort, there was no relationship between fatherhood and incident prostate cancer [hazard ratio (HR) 0.94, 95% confidence interval (CI) 0.86-1.02]. However, after stratifying for prostate cancer screening, prostate-specific antigen (PSA) unscreened childless men had a lower risk of prostate cancer (HR 0.73, 95% CI 0.58-0.91) compared with fathers due to the interaction between PSA screening and fatherhood (P for interaction < 0.01). A trend for the lower risk of prostate cancer among unscreened fathers compared with childless men was seen for low-grade prostate cancer (HR 0.78, 95% CI 0.61-1.01), high-grade prostate cancer (HR 0.62, 95% CI 0.37-1.04) and even fatal prostate cancer (HR 0.28, 95% CI 0.07-1.12). The number of children fathered was not related to prostate cancer (P(trend) = 0.17). In addition, men's inability to sire female offspring showed a weak positive association with prostate cancer in the PSA unscreened study subjects.

CONCLUSIONS

Our findings suggest fatherhood status and offspring gender is associated with a man's prostate cancer risk.

Male infertility and prostate cancer risk: a nested case-control study

The pathogenesis of prostate cancer is unclear, although experimental evidence implicates androgens as playing an important role. Infertile men frequently suffer from some degree of hypogonadism and may hence be hypothesized to be at lower risk of developing prostate cancer than fertile men. To test this hypothesis, we conducted a case-control study nested within "the Malmö Diet and Cancer Study" cohort in Sweden, inviting 661 prostate cancer cases and 661 age-matched controls to participate. Of the 975 (74%) respondents, we excluded 84 childless men with unknown fertility status. Thus, 891 men were included, providing 445 prostate cancer cases and 446 controls. Of these, 841 (94%) men were biological fathers and 50 (6%) men were infertile. Logistic regression showed that the infertile men were at significantly lower risk of being diagnosed with prostate cancer than the fertile men (odds ratio, 0.45; 95% confidence interval, 0.25-0.83). Conditional and unconditional multivariate models, adjusting for socioeconomic, anthropometric, and health-status-related factors, provided similar estimates. We conclude that enduring male infertility is associated with a reduced prostate cancer risk, thus corroborating the theory that normal testicular function, and hence most probably sufficient steroidogenesis, is an important contributing factor to the later development of this malignancy.

Increased risk of high-grade prostate cancer among infertile men

BACKGROUND

It has been reported that fatherhood status may be a risk factor for prostate cancer. In the current study, the authors examined the subsequent occurrence of prostate cancer in a cohort of men evaluated for infertility to determine whether male infertility is a risk factor for prostate cancer.

METHODS

A total of 22,562 men who were evaluated for infertility from 1967 to 1998 were identified from 15 California infertility centers and linked to the California Cancer Registry. The incidence of prostate cancer was compared with the incidence in an age-matched and geography-matched sample of men from the general population. The risk of prostate cancer in men with and those without male factor infertility was modeled using a Cox proportional hazards regression model.

RESULTS

A total of 168 cases of prostate cancer that developed after infertility were identified. Men evaluated for infertility but not necessarily with male factors were not found to have an increased risk of cancer compared with the general population (standardized incidence ratio [SIR], 0.9; 95% confidence interval [95% CI], 0.8-1.1). This risk was found to be highest for men with male factor infertility who developed high-grade prostate cancer (SIR, 2.0; 95% CI, 1.2-3.0). On multivariate analyses, men with male factor infertility were found to be 2.6 times more likely to be diagnosed with high-grade prostate cancer (hazard ratio, 2.6; 95% CI, 1.4-4.8).

CONCLUSIONS

Men with male factor infertility were found to have an increased risk of subsequently developing high-grade prostate cancer. Male infertility may be an early and identifiable risk factor for the development of clinically significant prostate cancer.

Androgens and prostate cancer risk

Androgens have been implicated in prostate tumourigenesis. However, no association between circulating levels of androgens and prostate cancer risk was found in a recent large pooled analysis of prospective studies. A decreased risk of prostate cancer among men treated with finasteride, a 5 alpha-reductase inhibitor which reduces levels of dihydrotestosterone, was observed in the Prostate Cancer Prevention Trial (PCPT), a large clinical trial. In the PCPT, a higher number of high-grade tumours was found in the finasteride group than in the control group; the reason for this finding is still unclear. Treatment of symptoms of late-onset hypogonadism - such as decreased muscle and bone mass and decreased cognition and libido - has become more prevalent with the advent of new forms of administration of testosterone replacement therapy. One small placebo-controlled study showed no increase in incidence of prostate cancer after 6 months of testosterone therapy, but data on the safety of testosterone replacement therapy remain limited.