Epidemiology of testicular cancer: An overview

Testicular cancer: a narrative review of the role of socioeconomic position from risk to survivorship

BACKGROUND

Testicular cancer (TC) is one of the most curable cancers. Given survival rates of close to 100% with appropriate therapy, ensuring proper treatment is essential. We reviewed and summarized the literature on the association of socioeconomic position (SEP) along the cancer control spectrum from risk factors to survivorship.

METHODS

We searched PubMed from 1966 to 2011 using the following terms: testicular cancer, testicular neoplasm, poverty, and socioeconomic factors, retrieving 119 papers. After excluding papers for the non-English (10) language and non-relevance (46), we reviewed 63 papers. We abstracted information on socioeconomic position (SEP), including occupation, education, income, and combinations of the 3. Five areas were examined: risk factors, diagnosis, treatment, survival, and survivorship.

RESULTS

Most studies examined area-based measures, not individual measures of SEP. The majority of studies found an increased risk of developing TC with high SEP though recent papers have indicated increased risk in low-income populations. Regarding diagnosis, recent papers have indicated that lower levels of education and SEP are risk factors for later-stage TC diagnosis and hence higher TC mortality. For treatment, 1 study that examined the use of radiation therapy (RT) in stage I seminoma reported that living in a county with lower educational attainment led to lower use of RT. For survival (mortality), several studies found that men living in lower SEP geographic areas experience lower survival and higher mortality.

CONCLUSION

The strongest evidence for SEP impact on testicular germ cell tumor (TGCT) was found for the risk of developing cancer as well as survival. The association of SEP with TGCT risk appears to have changed over the last decade. Given the highly curable nature of TGCT, more research is needed to understand how SEP impacts diagnosis and treatment for TGCT and to design interventions to address disparities in TGCT outcomes and SEP.

Comparative mRNA and microRNA expression profiling of three genitourinary cancers reveals common hallmarks and cancer-specific molecular events

BACKGROUND

Genome-wide gene expression profile using deep sequencing technologies can drive the discovery of cancer biomarkers and therapeutic targets. Such efforts are often limited to profiling the expression signature of either mRNA or microRNA (miRNA) in a single type of cancer.

METHODOLOGY

Here we provided an integrated analysis of the genome-wide mRNA and miRNA expression profiles of three different genitourinary cancers: carcinomas of the bladder, kidney and testis.

PRINCIPAL FINDINGS

Our results highlight the general or cancer-specific roles of several genes and miRNAs that may serve as candidate oncogenes or suppressors of tumor development. Further comparative analyses at the systems level revealed that significant aberrations of the cell adhesion process, p53 signaling, calcium signaling, the ECM-receptor and cell cycle pathways, the DNA repair and replication processes and the immune and inflammatory response processes were the common hallmarks of human cancers. Gene sets showing testicular cancer-specific deregulation patterns were mainly implicated in processes related to male reproductive function, and general disruptions of multiple metabolic pathways and processes related to cell migration were the characteristic molecular events for renal and bladder cancer, respectively. Furthermore, we also demonstrated that tumors with the same histological origins and genes with similar functions tended to group together in a clustering analysis. By assessing the correlation between the expression of each miRNA and its targets, we determined that deregulation of 'key' miRNAs may result in the global aberration of one or more pathways or processes as a whole.

CONCLUSIONS

This systematic analysis deciphered the molecular phenotypes of three genitourinary cancers and investigated their variations at the miRNA level simultaneously. Our results provided a valuable source for future studies and highlighted some promising genes, miRNAs, pathways and processes that may be useful for diagnostic or therapeutic applications.

Shedding light on testicular cancer

Testicular cancer, though generally uncommon, is the most common cancer NPs will see in young men. Advances in surgery, radiation, and cisplatin-based chemotherapy, have made testicular cancer a "model" for a curable cancer. Survivors will likely live many years, but will require lifelong follow-up for possible recurrence and long-term treatment sequelae.

Prognostic features and markers for testicular cancer management

Testicular neoplasm accounts for about 1% of all cancers in men. Over the last 40 years, the incidence of testicular cancer has increased in northern European male populations for unknown reasons. When diagnosed at early stage, testicular cancer is usually curable with a high survival rate. In the past three decades, successful multidisciplinary approaches for the management of testicular cancer have significantly increased patient survival rates. Utilization of tumor markers and accurate prognostic classification has also contributed to successful therapy. In this article, we highlight the most commonly used tumor markers and several potential "novel" markers for testicular cancer as part of the ongoing effort in biomarker research and discovery. In addition, this article also identifies several key prognostic features that have been demonstrated to play a role in predicting relapse. These features include tumor size, rete testis invasion, lymphovascular invasion, and tumor histology. Together with tumor markers, these prognostic factors should be taken into account for risk-adapted management of testicular cancer.

Screening for testicular cancer

BACKGROUND

Testicular cancer commonly affects men aged between 20 and 35 years. Screening for testicular cancer may reduce both morbidity and mortality, yet the effectiveness of any method is unknown. Equally, screening may also promote treatment procedures that are unwarranted or may adversely affect the health outcomes of the patient with no net benefit. Additionally, many organisations recommend against screening for testicular cancer due to the low incidence of testicular cancer and favourable outcomes in the absence of screening.

OBJECTIVES

The primary objective of this review is to determine whether screening for testicular cancer (physician or patient self-examination) reduces testicular cancer-specific mortality. The secondary objective of this review is to determine impact of screening for testicular cancer on quality of life and adverse outcomes.

SEARCH STRATEGY

Electronic searches were conducted across MEDLINE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL) and PsychINFO.

SELECTION CRITERIA

All published randomised controlled trials (RCTs) of screening versus no screening for testicular cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The search identified 19 potentially relevant articles, which were selected for full text review. None of the articles that were reviewed were evaluated as eligible for inclusion in this review.

MAIN RESULTS

There are no published RCTs evaluating the effectiveness of screening for testicular cancer.

AUTHORS' CONCLUSIONS

Patients with increased clinical risk factors for testicular cancer, including a family history of testicular cancer, undescended testis (cryptorchidism) or testicular atrophy should be informed by their physicians of their potential increased risk of testicular cancer, along with potential benefits and harms associated with screening.

Marijuana use and testicular germ cell tumors

BACKGROUND

Since the early 1970s, the incidence of testicular germ cell tumors (TGCTs) in the United States has been increasing; however, potential environmental exposures accounting for this increase have not been identified. A previous study reported a significant association between frequent and long-term current marijuana users and TGCT risk. The purpose of this study was to evaluate the relation between marijuana use and TGCTs in a hospital-based case-control study.

METHODS

TGCT patients diagnosed between January 1990 and October 1996 (n = 187) and male friend controls (n = 148) were enrolled in the study. All participants were between the ages of 18 and 50 at the time of diagnosis and resided in Texas, Louisiana, Arkansas, or Oklahoma. Associations of marijuana use and TGCTs were estimated using unconditional logistic regression, adjusting for age, race, prior cryptorchidism, cigarette smoking, and alcohol intake.

RESULTS

Overall, patients with TGCTs were more likely to be frequent marijuana users (daily or greater) compared with controls (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.0-5.1). Histological-specific analyses revealed that patients with nonseminoma were significantly more likely than controls to be frequent users (OR, 3.1; 95% CI, 1.2-8.2) and long-term (≥ 10 years) users (OR, 2.4; 95% CI, 1.0-6.1).

CONCLUSIONS

The finding of an association between frequent marijuana use and TGCTs, particularly among men with nonseminoma, was consistent with the findings of a previous report. Additional studies of marijuana use and TGCTs are warranted, especially studies evaluating the role of endocannabinoid signaling and cannabinoid receptors in TGCTs.

Testicular germ cell tumors: pathogenesis, diagnosis and treatment

Testicular germ cell tumors represent the most common solid malignancy of young men aged 15-40 years. Histopathologically, testicular germ cell tumors are divided into two major groups: pure seminoma and nonseminoma. The pathogenesis of testicular germ cell tumors remains unknown; however, cryptorchidism is the main risk factor, and molecular studies have shown strong evidence of an association between genetic alterations and testicular germ cell tumors. In cases of suspicion for testicular germ cell tumor, a surgical exploration with orchiectomy is obligatory. After completion of diagnostic procedures, levels of serum tumor markers and the clinical stage based on the International Union Against Cancer tumor-node-metastasis classification should be defined. Patients with early-stage testicular germ cell tumors are treated by individualized risk stratification within a multidisciplinary approach. The individual management (surveillance, chemotherapy or radiotherapy) has to be balanced according to clinical features and the risk of short-term and long-term toxic effects. Treatment for metastatic tumors is based on risk stratification according to International Germ Cell Cancer Collaborative Group classification and is performed with cisplatin-based chemotherapy and residual tumor resection in cases of residual tumor lesion. High-dose chemotherapy represents a curative option for patients with second or subsequent relapses.

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

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Case-control study of male germ cell tumors nested in a cohort of car-manufacturing workers: Findings from the occupational history

BACKGROUND

To examine whether the previously observed excess risk of male germ cell cancer in a cohort of car-manufacturing workers can be attributed to occupational activities inside and/or outside the car industry.

METHODS

A nested case-control study among workers in six plants included 205 cases of germ cell cancer and 1,105 controls, individually matched by year of birth (±2 years). Job periods of the individual occupational histories were coded based on the International Standard Classification of Occupations (ISCO) and the industrial classification of economic activities (NACE). Odds ratios (ORs) and corresponding 95%-confidence intervals (CI) for ever-never and cumulative employment were calculated by conditional multivariate logistic regression adjusted for cryptorchidism.

RESULTS

Significantly increased risks were observed for machinery fitters and assemblers (A) (OR = 1.8, 95% CI 1.25-2.53) and "workers not elsewhere classified" (OR = 2.10, 95% CI 1.27-3.54), but no trend was observed for employment duration in either occupational group. Stratification of job group A by metal-cutting and non-cutting jobs yielded ORs of 1.87 (95% CI 1.31-2.67) and of 1.24 (95% CI 0.68-2.28), respectively. Among "plumbers, welders, sheet & structural metal workers" (adjusted OR 1.4, 95% CI 0.99-1.95) only "structural metal preparers and erectors" showed a substantially increased risk (OR = 2.30; 95% CI 1.27-4.27).

CONCLUSIONS

Our results do not fully explain the increased incidence of germ cell cancer in the cohort, but support previous findings showing increased risks among metal workers. These risks were most strongly pronounced in metal-cutting activities.

Relation of isoflavones and fiber intake in childhood to the timing of puberty

BACKGROUND

It has been suggested that phytoestrogens and dietary fiber can affect puberty timing.

OBJECTIVE

We examined whether intake of isoflavone and fiber in healthy white children before their pubertal growth spurt [age at take-off (ATO)] was associated with puberty timing.

DESIGN

Multivariate regression analyses were performed in 227 DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study participants with 3-d weighed dietary records and information on potential confounders at baseline (1 and 2 y before ATO). In a subsample (n = 111), urinary isoflavones were determined in 24-h urine samples by gas chromatography-mass spectrometry analysis. Puberty timing was examined by using ATO and chronologic ages at pubertal stage 2 for breast development (B2) or gonadal development, peak height velocity (PHV), and menarche or voice break.

RESULTS

Girls whose diet was in the highest dietary isoflavone tertile experienced Tanner stage 2 for breast development ap 0.7 y later and reached PHV ap 0.6 y later than did girls whose diet was in the lowest isoflavone tertile [age (95% CI) at B2: 10.7 y (10.4, 10.9 y) compared with 10.0 y ( 9.7, 10.3 y), respectively; P for trend = 0.04; age at PHV: 11.9 y (11.6, 12.2 y) compared with 11.3 y (11.0, 11.6 y), respectively; P for trend = 0.04; adjusted for body mass index z score and fiber intake]. In boys, dietary isoflavones were not associated with pubertal markers. Urinary isoflavone and dietary fiber intakes were not associated with pubertal markers.

CONCLUSIONS

Girls, but not boys, with higher prepubertal isoflavone intakes appear to enter puberty at a later age. Fiber intake in this sample of healthy white girls and boys was not relevant for puberty timing.

Laparoscopic management of impalpable testis in children, new classification, lessons learned, and rare anomalies

INTRODUCTION

Cryptorchidism is the most common genitourinary anomaly in male children. About 20% of cryptorchid testicles are impalpable. Laparoscopy has become one of the important diagnostic modalities for the management of impalpable testes. The aim of the present study was in highlighting the lessons and rare anomalies encountered during the management of impalpable testes in children over a period of 10 years in a single pediatric surgery center and to establish a new classification that better describes the anomalies.

MATERIALS AND METHODS

A retrospective review of 93 laparoscopic explorations for nonpalpable testes between 1998 and 2008 was conducted. Demographic data, intraoperative findings and management, associated anomalies, and postoperative follow-up were collected and analyzed. A new laparoscopic classification is described.

RESULTS

Age range was 7 months to 8 years. Twenty bilateral versus 73 unilateral impalpable testes were operated on. Four groups were established with subgroups in each group. Group 1 (vanishing syndrome) had 44 cases, group 2 (peeping testes) had 21 cases, group 3 (intra-abdominal testes) had 38 cases, and group 4 (disorders of sex development) had 10 cases. Associated anomalies included 4 cases of Down syndrome, 7 cases of neurologic impairment, 3 of renal anomalies, 3 of cardiac anomalies, and 1 case of eye anomalies. Follow-up range was 1-6 years.

CONCLUSIONS

A new laparoscopic classification is presented that better describes the anomalies and help-in planning the treatment of impalpable testes. Impalpable testes with Down syndrome are sometimes associated with bizarre anatomy. Parents should be well informed of all the possible findings, especially in bilateral cases.

Ethnic and socioeconomic trends in testicular cancer incidence in New Zealand

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

Dietary protein intake throughout childhood is associated with the timing of puberty

Early puberty onset is associated with hormone-related cancers, but whether diet in childhood influences pubertal timing is controversial. We examined the association of protein intake in early and mid-childhood with the ages at take-off of the pubertal growth spurt (ATO), peak height velocity (APHV), and menarche in girls and voice break in boys using data from the longitudinal Dortmund Nutritional and Anthropometric Longitudinally Designed Study. Among participants who provided 3-d weighed dietary records at 12 mo, 18-24 mo, 3-4 y, and 5-6 y, 112 had sufficient anthropometric measurements between 6 and 13 y to allow estimation of ATO. Life-course plots were used to identify critical periods of total, animal, and vegetable protein intake (percentage of total energy intake) for pubertal timing. At these ages, the association between tertiles of protein intake (T1-T3) and the outcomes was investigated using multiple linear regression analysis. A higher total and animal protein intake at 5-6 y was related to an earlier ATO. In the highest tertile of animal protein intake at 5-6 y, ATO occurred 0.6 y earlier than in the lowest [(mean, 95% CI) T1: 9.6, 9.4-9.9 vs. T2: 9.4, 9.1-9.7 vs. T3: 9.0, 8.7-9.3 y; P-trend = 0.003, adjusted for sex, total energy, breast-feeding, birth year, and paternal university degree]. Similar findings were seen for APHV (P-trend = 0.001) and the timing of menarche/voice break (P-trend = 0.02). Conversely, a higher vegetable protein intake at 3-4 and 5-6 y was related to later ATO, APHV, and menarche/voice break (P-trend = 0.02-0.04). These results suggest that animal and vegetable protein intake in mid-childhood might be differentially related to pubertal timing.

Diet quality in childhood is prospectively associated with the timing of puberty but not with body composition at puberty onset

We examined whether the diet quality of healthy children prior to the pubertal growth spurt was associated with age and body composition at puberty onset. Multivariate regression analyses were performed using data from 222 Dortmund Nutritional and Anthropometric Longitudinally Designed Study participants (mean age +/- SD at baseline: 7.4 +/- 1.3 y) with 3-d weighed dietary records and anthropometric data at baseline, i.e. the visits 2 and 3 y before the onset of pubertal growth spurt [defined as age at take-off (ATO)]. Diet quality at baseline was determined using the nutrient density-based Nutritional Quality Index (NQI) and the food group and nutrient-based Revised Children's Diet Quality Index (RC-DQI). Based on their distribution, 3 NQI or RC-DQI categories were created to indicate lower, moderate, and higher diet quality. Parameters describing body composition at ATO were age- and gender-specific Z-scores of BMI, fat mass/height(2), and fat-free mass/height(2). Children with lower diet quality indicated by lower NQI scores entered puberty approximately 0.4 y earlier than children with higher NQI scores {ATO in lower and higher NQI categories were [mean (95% CI)] 9.2 y (9.0-9.4), and 9.6 y (9.4-9.9), adjusted for sex, maternal overweight, baseline energy intake, and baseline BMI Z-score} (P-value = 0.02). A similar association of the RC-DQI with ATO was largely explained by baseline energy intakes. Our data suggest that diet quality was not independently associated with body composition at ATO. Children with lower diet quality according to a nutrient density-based index appear to enter puberty at an earlier age, independently of prepubertal body composition.

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

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

Birth and early life influences on the timing of puberty onset: results from the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study

BACKGROUND

Early age at puberty onset may predispose an individual to many currently prevalent diseases, including cancer and adiposity.

OBJECTIVE

The objective was to investigate whether early life exposures influence the timing of puberty, as defined by both early and late markers, in healthy German girls and boys.

DESIGN

Term participants (n = 215; 49.8% female) of the DONALD (DOrtmund Nutritional and Anthropometric Longitudinally Designed) Study, with sufficient repeated anthropometric measurements between 6 and 13 y to allow estimation of age at take-off of the pubertal growth spurt (ATO) and information on a variety of early life exposures, including birth weight, breastfeeding status, velocity of weight gain, and parental characteristics, were studied. Age at peak height velocity (APHV) and menarche were also considered.

RESULTS

Children who weighed between 2500 and <3000 g at birth were approximately 7 mo younger at ATO than were the other children (beta +/- SE: -0.56 +/- 0.20 y; P = 0.006). Children who had gained weight rapidly between birth and 24 mo (increase in weight SD score >0.67) experienced ATO 4 mo earlier than those who had gained weight normally (-0.34 +/- 0.15 y; P = 0.02). Rapid weight gain was also associated with an earlier APHV (P = 0.0006) and, in girls, with an earlier menarche (P = 0.002). Adjustment for body mass index SD score or body fat percentage 1, 2, or 3 y before ATO did not account for these effects.

CONCLUSION

In both boys and girls, intrauterine and early postnatal growth factors appear to influence both early and later markers of puberty onset independently of prepubertal body composition.

Educational inequalities in cancer incidence in Turin, Italy

The objective of this study was to investigate the relationship between cancer incidence and socioeconomic status, and to examine the temporal trends in social inequalities in cancer risk. Educational differentials in the incidence of cancer (25 sites) among adult residents of Turin (Italy) were examined using data from the Turin Longitudinal Study and the Piedmont Cancer Registry. The relationship between cancer incidence and educational level was evaluated over three 5-year periods between 1985 and 1999 using Poisson models. An estimated 17% of malignancies among men in the low-educational group were attributable to education, whereas women with a low educational level were slightly protected. Less-educated men had higher risks of upper aero-digestive tract, stomach, lung, liver, rectal, bladder, central nervous system and ill-defined cancers, and lower risks of melanoma, kidney and prostate cancers. Women with lower educational levels were at higher risk of stomach, liver and cervical cancers, whereas they were less likely to be diagnosed with melanoma, ovarian and breast cancers. For most sites, the educational gradient in risk did not vary substantially over time. The educational inequalities in cancer incidence observed in this cohort appear similar in magnitude and direction to socioeconomic inequalities found in other Western countries; for some cancer sites results partly differ from the results of other studies, and require further investigation. A thorough understanding of the relative burden of well-documented causes of social inequalities in cancer risk is essential to address preventive measures and to direct future research on unexplained social differences.

Effect modification of endocrine disruptors and testicular germ cell tumour risk by hormone-metabolizing genes

It has been hypothesized that the increased prevalence of testicular germ cell tumours (TGCT) may be attributable to endocrine disrupting chemicals, such as persistent organic pollutants (POPs); these may be modulated by hormone-metabolizing enzymes. Using data from 568 cases and 698 controls enrolled in the US Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study, we examined associations between TGCT and POPs, including p,p'-dichlorodiphenyldichloroethylene, chlordane-related compounds and polychlorinated biphenyls (PCBs), modified by polymorphisms in five hormone-metabolizing genes (CYP17A1, CYP1A1, HSD17B1, HSD17B4 and AR). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models that stratified associations of POP exposure and TGCT risk by genotype. Two polymorphisms in CYP1A1, rs1456432 and rs7495708, modified the association between trans-nonachlor and total chlordanes and TGCT risk. Among men with a minor allele for rs1456432, those with the highest quartiles had an increased risk of TGCT (OR = 1.90, 95% CI, 1.01-3.56) compared with those with the lowest; there was no increased risk among men with the homozygous major allele genotype (p-interactions = 0.024). Similar results were seen for rs7495708. HSD17B4 rs384346 modified the associations between TGCT risk and PCB-118 and PCB-138 concentrations: the 45-55% reductions in TGCT risk for men with the highest quartiles compared with the lowest quartiles were only present in those who had a major homozygous allele genotype (p-interactions < 0.04). Thus, there are suggestions that certain CYP1A1 and HSD17B4 polymorphisms may modify the associations between POPs and TGCT risk. With false discovery rate values >0.2, however, caution is advisable when interpreting the findings of this study.

Impact of chemotherapeutics and advanced testicular cancer or Hodgkin lymphoma on sperm deoxyribonucleic acid integrity

OBJECTIVE

To determine the impact of combination chemotherapy on the quality of newly generated spermatozoa from patients with advanced testicular cancer and patients with Hodgkin lymphoma (HL).

DESIGN

Prospective longitudinal study.

SETTING

Academic facility.

PATIENT(S)

Patients with newly diagnosed metastatic testicular cancer and with HL that required chemotherapy were compared with age-matched healthy community volunteers.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen parameters, hormone levels, testis volume, and presence of sperm DNA strand breaks in patients with cancer and in healthy community volunteers were compared before and after the patients' chemotherapy at 6, 12, 18, and 24 months.

RESULT(S)

Before chemotherapy, both cancer groups had poorer semen quality compared with community volunteers. Among patients with testicular cancer and HL, 67% and 60%, respectively, had <5x10(6) sperm/mL at 6 months after chemotherapy. At 24 months, 60% and 57% of patients with testicular cancer and HL, respectively, had normal sperm concentrations. Level of FSH was significantly higher in the cancer group compared with community volunteers at 6 to 12 months after chemotherapy. Before chemotherapy, sperm DNA damage was higher in the cancer group than in community volunteers; this damage was increased further at 6 months and remained elevated 24 months after treatment.

CONCLUSION(S)

Sperm generated after chemotherapy maintain a significant degree of chromatin damage. Therefore, survivors of testicular cancer and HL are at risk of having abnormal reproductive outcome. Proper counseling to these patients on reproductive risks and fertility preservation before chemotherapy is recommended.

Association of marijuana use and the incidence of testicular germ cell tumors

BACKGROUND

The incidence of testicular germ cell tumors (TGCTs) has been increasing the past 4 to 6 decades; however, exposures that account for this rise have not been identified. Marijuana use also grew during the same period, and it has been established that chronic marijuana use produces adverse effects on the human endocrine and reproductive systems. In this study, the authors tested the hypothesis that marijuana use is a risk factor for TGCT.

METHODS

A population-based, case-control study of 369 men ages 18 to 44 years who were diagnosed with TGCT from January 1999 through January 2006 was conducted in King, Pierce and Snohomish Counties in Washington State. The responses of these men to questions on their lifetime marijuana use were compared with the responses of 979 age-matched controls who resided in the same 3 counties during the case diagnosis period.

RESULTS

Men with a TGCT were more likely to be current marijuana smokers at the reference date compared with controls (odds ratio [OR], 1.7; 95% confidence interval [95% CI], 1.1-2.5). In analyses according to histologic type, most of the association between current marijuana use and TGCT was observed in men who had nonseminomas/mixed histology tumors (current use: OR, 2.3; 95% CI, 1.3-4.0). Age at first use among current users (age<18 years [OR, 2.8] vs age>or=18 years [OR, 1.3]) and frequency of use (daily or weekly [OR, 3.0] vs less than once per week [OR, 1.8]) appeared to modify the risk.

CONCLUSIONS

An association was observed between marijuana use and the occurrence of nonseminoma TGCTs. Additional studies of TGCTs will be needed to test this hypothesis, including molecular analyses of cannabinoid receptors and endocannabinoid signaling, which may provide clues regarding the biologic mechanisms of TGCTs.

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.

Physical activity in adolescence and testicular germ cell cancer risk

OBJECTIVE

Several, but not all, studies have observed increased risks of testicular germ cell cancer (TGCC) associated with bicycling and other recreational activities. To further examine whether physical activity (PA) in adolescence is associated with TGCC risk, the authors conducted a case-control study in western Washington State.

METHODS

Cases (n = 391) were men diagnosed with TGCC, who were identified through a population-based cancer registry. Controls (n = 1,023) were men identified from the general population in western Washington State by using random digit telephone dialing. Participants were queried about various specific PA in grades 7-12 including bicycling, horseback riding, competitive sports, physical education class, as well as moderate, vigorous, and sedentary activities in general.

RESULTS

In multivariate analyses, bicycling, vigorous-intensity activities, and sedentary activities were not associated with TGCC risk, while horseback riding and wrestling were associated with decreased risks, and moderate-intensity activities, soccer, basketball, and intermediate duration of competitive activities were associated with increased risks.

CONCLUSIONS

The lack of internal consistency of the findings within the current study and of findings among prior studies suggests that PA contributes little, if any, to the risk of TGCC.

Microsatellite instability, mismatch repair deficiency, and BRAF mutation in treatment-resistant germ cell tumors

PURPOSE

Mismatch repair (MMR) deficiency and microsatellite instability (MSI) are associated with cisplatin resistance in human germ cell tumors (GCTs). BRAF mutation (V600E) is found in MSI colorectal cancers. The role of RAS/RAF pathway mutations in GCT treatment response is unknown.

PATIENTS AND METHODS

Two patient cohorts were investigated: 100 control GCTs (50 seminomas and 50 nonseminomas) and 35 cisplatin-based chemotherapy-resistant GCTs. MMR proteins were analyzed by immunohistochemistry, and eight microsatellite loci were examined for MSI. Tumors were assessed for specific BRAF and KRAS mutations.

RESULTS

Resistant tumors showed a higher incidence of MSI than controls: 26% versus 0% in two or more loci (P < .0001). All resistant tumors were wild-type KRAS, and two controls (2%) contained a KRAS mutation. There was a significantly higher incidence of BRAF V600E mutation in resistant tumors compared with controls: 26% versus 1% (P < .0001). BRAF mutations were highly correlated with MSI (P = .006), and MSI and mutated BRAF were correlated with weak or absent staining for hMLH1 (P = .017 and P = .008). Low or absent staining of hMLH1 was correlated with promoter hypermethylation (P < .001). Tumors lacking expression of hMLH1 or MSH6 were significantly more frequent in resistant GCTs than in controls (P = .001 and 0.0036, respectively). Within the subgroup of resistant tumors, patients with MSI showed a trend to longer progression-free survival (P = .068).

CONCLUSION

We report for the first time a correlation between a gene mutation--BRAF V600E--and cisplatin resistance in nonseminomatous GCTs. Furthermore, a correlation between MMR deficiency, MSI, and treatment failure is confirmed.

Maternal smoking during pregnancy and testicular cancer in the sons: a nested case-control study and a meta-analysis

Some large ecological studies have noted a significant association of testicular cancer (TC) with maternal smoking during pregnancy, while several more controlled studies have been negative. It has been difficult to obtain reliable data on exposure because of the long lag time to cancer diagnosis. We performed a case-control study nested within Finnish, Swedish and Icelandic maternity cohorts exploiting early pregnancy serum samples to evaluate the role of maternal smoking in the risk of TC in the offspring. After reviewing the literature, we also performed a meta-analysis of published studies. For each index mother of the TC patient, three to nine matched control mothers with a cancer-free son born at the same time as the TC case were identified within each cohort. First trimester sera were retrieved from the 70 index mothers and 519 control mothers and were tested for cotinine level by a novel HPLC-MS-MS method developed. No statistically significant association between maternal cotinine level and risk of TC in the offspring was found (OR 0.68; 95% CI 0.35, 1.34). This is the first study based on individual exposure measurements. Its results agree with our meta-analysis of seven previous epidemiological studies (total number of 2149 cases, 2762 controls) using indirect exposure assessment (OR 1.0; 95% CI 0.88, 1.12).

The International Testicular Cancer Linkage Consortium: a clinicopathologic descriptive analysis of 461 familial malignant testicular germ cell tumor kindred

OBJECTIVES

Familial aggregation of testicular germ cell tumor (TGCT) has been reported, but it is unclear if familial TGCT represents a unique entity with distinct clinicopathologic characteristics. Here we describe a collection of familial TGCT cases from an international consortium, in an effort to elucidate any clinical characteristics that are specific to this population.

MATERIALS AND METHODS

Families with >or=2 cases of TGCT enrolled at 18 of the sites participating in the International Testicular Cancer Linkage Consortium were included. We analyzed clinicopathologic characteristics of 985 cases from 461 families.

RESULTS

A majority (88.5%) of families had only 2 cases of TGCT. Men with seminoma (50% of cases) had an older mean age at diagnosis than nonseminoma cases (P = 0.001). Among individuals with a history of cryptorchidism, TGCT was more likely to occur in the ipsilateral testis (kappa = 0.65). Cousin pairs appeared to represent a unique group, with younger age at diagnosis and a higher prevalence of cryptorchidism than other families.

CONCLUSIONS

Clinicopathologic characteristics in these familial TGCT cases were similar to those generally described for nonfamilial cases. However, we observed a unique presentation of familial TGCT among cousin pairs. Additional studies are needed to further explore this observation.

Risk of cancer in first- and second-degree relatives of testicular germ cell tumor cases and controls

Risk factors for testicular germ cell tumors (TGCT) have not been well identified; however, data suggest that risks of cancer in family members of men with TGCT is elevated. Using family history data from 738 cases and 904 controls enrolled in the U.S. Servicemen's Testicular Tumor Environmental and Endocrine Determinants (STEED) Study from 2002 to 2005, the risk of cancer in first- and second-degree family members of these men was examined. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, adjusting for reference age of case or control, race/ethnicity of case or control, sex of family member and lineage (maternal vs. paternal). An increased risk of all cancer among first-degree relatives of cases compared to controls was observed (RR = 1.17, 95% CI: 1.01-1.35). There were suggestions of differences in risk when stratifying all relatives by lineage. For maternal relatives, there was a statistically significant increased risk of all cancer (RR = 1.16, 95% CI: 1.04-1.30), digestive tract (RR = 1.52, 95% CI: 1.15-2.00) and male genital organ cancer (RR = 1.70, 95% CI: 1.15-2.51); there was also a suggestion of increased risks of hematopoetic cancers, cancers in the female genital organs and nonmelanoma skin cancer. For paternal relatives, there was a statistically significant association only with decreased risk of lung cancer (RR = 0.69, 95% CI: 0.51-0.94). Thus, this study suggests that there may be aggregation of cancer among families of men diagnosed with TGCT.

Increased prevalence of testicular microlithiasis in men with familial testicular cancer and their relatives

Testicular germ cell tumours (TGCT) cluster in families, but responsible genes remain unidentified. The association between testicular microlithiasis (TM) and testicular carcinoma in situ (CIS) suggests that TM may be a TC risk factor. We report testicular ultrasound findings in men with familial TGCT (FTGCT) and their unaffected relatives. A total of 81 men (48 affected and 33 unaffected) from 31 families with > or =2 TC cases underwent testicular ultrasound. Testicular microlithiasis was defined as either 'classic' (> or =5 microliths) or 'limited' (<5 microliths). Statistical analyses used Fisher's exact test and permutation testing. Testicular microlithiasis was more frequent in the contralateral testicles of men with a history of TGCT (affected men) than in unaffected men (48 vs 24%, P=0.04). The association appeared stronger for classic TM (21 vs 9%) than for limited TM (27 vs 15%). Testicular microlithiases were bilateral in six out of seven (87%) unaffected men. Among affected men, TM was not associated with histology, age at diagnosis or cancer treatment. Of the 31 families, 10 accounted for a majority (61%) of the TM cases identified (P=0.11). Testicular microlithiasis was more prevalent among FTGCT family members than described previously in the general population, and was more common among FTGCT cases vs unaffected blood relatives. Testicular microlithiasis appeared to cluster in certain families. These findings suggest both a familial predisposition to TM and an association between TM and FTGCT. If proven, this could be clinically important to men in FTGCT families, and may be useful in identifying specific genes involved in FTGCT.

A population-based analysis of 788 cases of yolk sac tumors: A comparison of males and females

Yolk sac tumors (YST) are a rare and aggressive germ cell tumor. The objective of this study is to compare the patient characteristics and survival of YST in males and females. Demographic and clinicopathologic information were obtained from the Surveillance, Epidemiology, and End Results Program from 1973 to 2003. Statistical analysis was performed using Independent-sample t-test, chi(2) test, Kaplan-Meier methods and Cox proportional hazards regression. Seven hundred eighty-eight patients were identified, 451 (57%) were males and 337 (43%) were females. The mean age at diagnosis was similar in males and females. The age at diagnosis showed a bimodal distribution with an increased incidence in the first 4 years of life and during the 2nd to 4th decade of life. The most common site of the primary tumor was gonadal, namely testis 336 (42.6%) and ovary 257 (32.6%). Among the extragonadal sites, tumor site of origin differed in males and females. The 5-year survival of extragonadal YST (66%) was worse than gonadal YST (86%) (p < 0.05). The overall median survival for the cohort was 87 months. This was similar in males (81 months) and females (91 months) (p > 0.05). As the year of diagnosis progressed from 1973 to 2003, survival of both males and females with YST consistently improved. The bimodal age distribution of YST generates the hypothesis that sex steroids may play a role in selected YST. Although the overall survival in all YST patients has improved over the past few decades, the primary sites of origin differ in males and females and impact prognosis.

Cancer in American Indian and Alaska Native young adults (ages 20-44 years): US, 1999-2004

BACKGROUND

An examination of cancer incidence patterns in American Indians and Alaska Native (AI/AN) young adults may provide insight into their present and future cancer burden.

METHODS

To reduce racial misclassification, incidence data were linked with the Indian Health Service (IHS) patient services database. Age-adjusted cancer incidence rates per 100,000 (AAR) and corresponding rate ratios (RR) for young adults (ages 20-44 years) were compared across IHS regions and for selected cancers within Contract Health Service Delivery Area counties by race (AI/AN vs non-Hispanic whites [NHW]) and sex.

RESULTS

The all-sites cancer incidence rate was lower for AI/ANs (AAR of 83.8) than for NHWs (AAR of 111.2) (RR of 0.75) but varied by IHS regions. Among the leading cancers in AI/AN females the risk was elevated for stomach (RR of 3.22), colorectal (RR of 1.30), uterine (RR of 1.61), and kidney (RR of 1.39) cancers and was lower for breast (RR of 0.70) and thyroid (RR of 0.71) cancers. Among AI/AN young adult males the risk was elevated for stomach (RR of 2.62), liver (RR of 1.89), and kidney (RR of 1.59) cancers and lower for testicular germ cell cancer (RR of 0.64) and lymphoma (RR of 0.60). The risk for these and other cancers varied across IHS regions.

CONCLUSIONS

Many of the cancer patterns that characterize the AI/AN population overall are apparent among young adults. Compared with NHW young adults, the overall cancer burden among AI/AN young adults was lower but varied for selected cancers and across IHS regions. Cancer control and research strategies are needed to address the unique genetic, social, cultural, and lifestyle aspects of AI/AN young adults.

Tallness is associated with risk of testicular cancer: evidence for the nutrition hypothesis

The pathogenesis of testicular germ cell tumours (GCTs) is potentially influenced by high-energy nutrition during infancy. As adult height is a proxy for childhood nutrition, we investigated the role of nutrition in GCT pathogenesis by comparing stature of patients with healthy men. In a matched case–control study, 6415 patients with GCT were compared with healthy army conscripts (1:6 matching modus) with regard to height (cm) and body mass index (BMI; kg/m²). Statistical analysis involved tabulation of descriptive height measures and BMI. Conditional logistic regression models were used to quantify the association of GCT with height, with odds ratios (OR) adjusted for BMI. The literature was searched for studies on stature in GCT patients. Body size is significantly associated with risk of GCT, very tall men (>195 cm) having a GCT risk of OR=3.35 (95% confidence intervals (CI): 2.88–3.90; adjusted). Short stature is protective (OR=0.798; 95% CI: 0.68–0.93). Both histologic subgroups are associated with tallness. Of 16 previous reports, 7 were confirmative, 5 had null and 4 equivocal results. The association of stature with GCT risk accords with the nutrition hypothesis of GCT. This study expands the current view of GCT tumorigenesis by suggesting that high-calorie intake in childhood promotes GCT precursors originating in utero.

Tumor development in three patients with Noonan syndrome

The diagnosis of Noonan syndrome is essentially clinical, based upon the distinct phenotype and the involvement of the cardiovascular system. Tumor development is a rare manifestation of Noonan syndrome but can be explained by the molecular pathophysiology involved in the disorder. We present three Noonan patients who developed solid tumors. The first patient, a 4-year-old girl, developed granular cell tumors as did her mother in childhood. The second patient, a 1-year-old boy, had a low grade pilocytic astrocytoma, the clinical expression of which was persistent headache. MRI showed a pituitary mass in the posterior lobe. It was surgically removed. The third patient, a 7-year-old boy was found to have Sertoli tumors in his right cryptorchid testis. All three patients fulfilled the clinical criteria for Noonan syndrome. However, genetic testing was negative in patients 1 and 3. The diagnosis of Noonan syndrome was made based on distinct phenotypic findings in three patients who had different types of tumors.

[Follow-up of adult patients with myelomeningocele]

The adult outcome of spina bifida patients is fraught with multiple problems reflecting the multisystemic nature of the disease. These problems result in both mortality, actually caused in most cases by the shunt, and morbidity, mostly affecting locomotion and sphincter control. These patients can thus lose ambulation and suffer from worsening incontinence and kidney function. The result in the vast majority of cases is a poor functional and socioprofessional outcome. The patients' demands regarding their occupational and affective lives, as well as procreation, must be heard. This requires a multidisciplinary approach, and pediatric and adult, as well as patient education and financial support for maintaining the patient's autonomy and medical acts allowing the viability of continued medical care.

Social inequality and incidence of and survival from male genital cancer in a population-based study in Denmark, 1994-2003

We investigated the effects of socioeconomic, demographic and health-related indicators on the incidence of and survival from prostate and testicular cancer diagnosed 1994-2003 with follow-up through 2006 in Denmark using information from nationwide registers. The analyses were based on data on 8279 men with prostate cancer and 1770 with testicular cancer in a cohort of 3.22 million persons born between 1925 and 1973 and aged >or=30 years. We found that men with higher education and the highest disposable income had the highest incidence of prostate cancer. The 1-year and 5-year relative survival after prostate cancer were best amongst men of the highest socioeconomic position. We found no substantial social gradients in the incidence of or survival from testicular cancer.

Characterization of sperm chromatin quality in testicular cancer and Hodgkin's lymphoma patients prior to chemotherapy

BACKGROUND

Although the incidences of testicular cancer and Hodgkin's lymphoma have increased in young men over the past decade, combination chemotherapy has improved survival. As fertility is of importance to these patients, characterization of sperm chromatin structure is needed. We assessed sperm chromatin in testicular cancer and Hodgkin's lymphoma patients prior to chemotherapy, in comparison with control community and idiopathic infertile volunteers.

METHODS

DNA damage was assessed with the sperm chromatin structure assay (SCSA), terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and comet assays; reactive thiols (SH) and DNA compaction were determined with the monobromobimane (mBBr) and chromomycin A3 (CMA3) assays, respectively.

RESULTS

Both testicular cancer (37%) and Hodgkin's lymphoma (81%) patients had normospermic samples with increased DNA damage, compared with controls. Cancer patients also had higher reactive thiols and CMA3 staining, indicating low DNA compaction.

CONCLUSIONS

Sperm DNA integrity and compaction were affected in testicular cancer and Hodgkin's lymphoma patients prior to chemotherapy. Although SCSA, TUNEL and comet assays all detected DNA damage, the latter was optimal for use in cancer patients. A combination of the comet assay with tests that evaluate sperm DNA compaction, such as flow cytometry-based CMA3 and mBBr assays, is a reliable strategy to characterize sperm chromatin quality in cancer patients at the time of sperm banking.

Characteristics related to the maternal intrauterine environment and risk of epithelial ovarian cancer

PURPOSE

In contrast to other hormonally mediated cancers such as those of the breast, prostate, and testes, almost no data are available regarding the relation of prenatal characteristics and exposures to subsequent ovarian carcinogenesis. In a population-based study of 812 women ages 35-74 years with epithelial ovarian cancer diagnosed in Washington State from 2002 to 2005 and 1313 controls, we assessed the relation of such factors to disease risk.

METHODS

Information was collected through in-person interviews and logistic regression was used to calculate odds ratios and 95% confidence intervals.

RESULTS

Overall, we noted little evidence that prenatal or birth characteristics including birth weight, birth order, maternal age, or in utero exposure to cigarette smoking were associated with risk of epithelial ovarian cancer in adulthood. Among women younger than 55 years of age, risk was reduced among those whose weight at birth was < 5.5 pounds (odds ratio and 95% confidence interval 0.54, 0.31-0.94) relative to those with birth weight 5.5-9 pounds.

CONCLUSIONS

In this study, birth weight was associated with risk of epithelial ovarian cancer only among women younger than 55 years of age. Prenatal influences might be expected to more substantially influence cancer risk at younger ages. Other reports examining associations of ovarian cancer risk with birth weight or other prenatal characteristics are few and have not examined risk separately according to age at diagnosis, suggesting that additional studies may prove useful.

Testicular cancer: marked birth cohort effects on incidence and a decline in mortality in southern Netherlands since 1970

The aim of our study was to interpret the changing incidence, and to describe the mortality of patients with testicular cancer in the south of the Netherlands between 1970 and 2004. On the basis of data from the Eindhoven Cancer Registry and Statistics Netherlands, 5-year moving average standardised incidence and mortality rates were calculated. An age-period-cohort (APC) Poisson regression analysis was performed to disentangle time and birth cohort effects on incidence. The incidence rate remained stable for all ages at about 3 per 100,000 person-years until 1989 but increased annually thereafter by 4% to 6 in 2004. This increase can almost completely be attributed to an increase in localised tumours. The largest increase was found for seminoma testicular cancer (TC) patients aged 35-39 and non-seminoma TC patients aged 20-24 years. Relatively more localised and tumours with lymph node metastases were detected in the later periods. APC analysis showed the best fit with an age-cohort model. An increase in incidence of TC was found for birth cohorts since 1950. The mortality rate dropped from 1.0 per 100,000 person-years in 1970 to 0.3 in 2005, with a steep annual decline of 12% in the period 1979-1986. In conclusion, the increase in incidence of TC was strongly correlated with birth cohorts since 1945. The increase in incidence is possibly caused by in utero or early life exposure to a yet unknown risk factor. There was a steep decline in mortality in the period 1979-1986.