Birth dates of men with cancer of the testis

Parental occupations at birth and risk of adult testicular germ cell tumors in offspring: a French nationwide case-control study

Background

Testicular germ cell tumors (TGCT) are the most frequent cancer in young men in developed countries. Parental occupational exposures during early-life periods are suspected to increase TGCT risk. The objective was to estimate the association between parental occupations at birth and adult TGCT.

Methods

A case-control study was conducted, including 454 TGCT cases aged 18-45 from 20 French university hospitals, matched to 670 controls based on region and year of birth. Data collected from participants included parental jobs at birth coded according to the International Standard Classification of Occupation-1968 and the French nomenclature of activities-1999. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors.

Results

Paternal jobs at birth as service workers (OR = 1.98, CI 1.18-3.30), protective service workers (OR = 2.40, CI 1.20-4.81), transport equipment operators (OR = 1.96, CI 1.14-3.37), specialized farmers (OR = 2.66, CI 1.03-6.90), and maternal jobs as secondary education teachers (OR = 2.27, CI 1.09-4.76) or in secondary education (OR = 2.35, CI 1.13-4.88) were significantly associated with adult TGCT. The risk of seminoma was increased for the above-mentioned paternal jobs and that of non-seminomas for public administration and defence; compulsory social security (OR = 1.99, CI 1.09-3.65); general, economic, and social administration (OR = 3.21, CI 1.23-8.39) for fathers; and secondary education teacher (OR = 4.67, CI 1.87-11.67) and secondary education (OR = 3.50, CI 1.36-9.01) for mothers.

Conclusion

Some paternal jobs, such as service workers, transport equipment operators, or specialized farmers, and maternal jobs in secondary education seem to be associated with an increased risk of TGCT with specific features depending on the histological type. These data allow hypotheses to be put forward for further studies as to the involvement of occupational exposures in the risk of developing TGCT, such as exposure to pesticides, solvents, or heavy metals.

No evidence for seasonal variations of the incidence of testicular germ cell tumours in Germany

The pathogenesis of testicular germ cell tumours (GCTs) is still incompletely understood. Any progress in its understanding must derive from observational studies. Recently, it has been suggested that the incidence of GCTs may follow a seasonal pattern based on circannual changes in the Vitamin D serum levels, with maximum incidence rates in winter months. To examine this promising hypothesis, we studied monthly incidence rates of testicular GCTs in Germany by analysing 30,988 GCT cases aged 15-69 years, diagnosed during 2009-2019. Monthly incident case numbers with data regarding histology and patient age were obtained from the Robert Koch Institut, Berlin, along with annual male population counts. We used precision weighting for deriving pooled monthly incidence rates for GCTs of the period 2009-2019. We stratified pooled rates by histology (seminoma and nonseminoma) and age (15-39 and 40-69 years). By assuming a cyclical effect, we used an estimator of the intensity of seasonal occurrence and report seasonal relative risks (RR). The mean monthly incidence rate was 11.93/105 person-months. The seasonal RR for testicular cancer over-all is 1.022 (95% CI 1.000-1.054). The highest seasonal RR was found in the subgroup of nonseminoma aged 15-39 years, with a RR 1.044 (95% CI 1.000-1.112). The comparison of the pooled monthly rates of the winter months (October-March) with the summer months (April-September) revealed a maximum relative difference of 5% (95% CI 1-10%) for nonseminoma, aged 15-39 years. We conclude that there is no evidence of a seasonal variation of incidence rates of testicular cancer. Our results are at odds with an Austrian study, but the present data appear sound because the results were obtained with precision weighted monthly incidence rates in a large population of GCT cases.

Risk of primary childhood brain tumors related to season of birth in Kumamoto Prefecture, Japan

OBJECTIVE

Environmental factors present around the time of birth may induce the development of childhood cancer. Some studies suggested an excess of brain tumors in children born during the winter months. The aim of this study was to look for evidence of the seasonality of birth in children who were younger than 15 years at the time of brain tumor diagnosis in the Kumamoto Prefecture, Japan.

METHODS

We surveyed 115 patients younger than 15 years who were diagnosed with primary intracranial tumors. All patients were born between 1989 and 2003.

RESULTS

We found a statistically significant difference between the season of their birth and the expected distribution of birth dates in the Kumamoto Prefecture (p = 0.028). Among the different diagnostic groups there was a statistically significant winter peak in the birth of patients with germ cell tumor (p = 0.001). No statistically significant seasonal patterns were detected in the birth season of patients with astrocytoma, malignant glioma, and medulloblastoma.

CONCLUSIONS

Although our data provide modest support for a winter peak in the birth of children with brain tumors, we posit that there may be yet unknown, complex biological mechanisms that account for these putative seasonal patterns.

Epidemiology of testicular cancer: An overview

Testicular cancer is a rare disease, accounting for 1.1% of all malignant neoplasms in Canadian males. Despite the low overall incidence of testicular cancer, it is the most common malignancy among young men. The incidence rate of testicular cancer has been increasing since the middle of the 20th century in many western countries. However, the etiology of testicular cancer is not well understood. A search of the peer-reviewed literature was conducted to identify important articles for review and inclusion in this overview of the epidemiology of testicular cancer. Most of the established risk factors are related to early life events, including cryptorchidism, carcinoma in situ and in utero exposure to estrogens. Occupational, lifestyle, socioeconomic and other risk factors have demonstrated mixed associations with testicular cancer. Although there are few established risk factors for testicular cancer, some appear to be related to hormonal balance at various life stages. Lifestyle and occupational exposures occurring later in life may play a role in promoting the disease, although they are not likely involved in cancer initiation. In addition to summarizing the current epidemiologic evidence on risk factors for testicular cancer, we suggest future research directions that may elucidate the etiology of testicular cancer.

Use of the scan statistic to detect temporal clustering of poisonings

The purpose of this study is to explore the use of the scan test to detect temporal clustering of poison control center data. We applied the scan test to a computerized data set consisting of all cases of carbon monoxide poisoning reported to our Poison Control Center in 1988. Using a time window of three days, the scan test identified three statistically significant temporal clusters. A review of case and climatologic data revealed that two of the clusters were due to family outbreaks and one was due to a sudden cold spell. We conclude that the scan test is a potentially useful surveillance tool which can be easily applied to poison control center data.

Cryptorchidism: a registry based study in Sweden on some factors of possible aetiological importance

STUDY OBJECTIVE

To examine the epidemiological characteristics of boys with cryptorchidism.

DESIGN

Cohort survey using the Swedish personal identification code and Medical Birth Registry to link cryptorchid boys with their pregnancy and delivery data. They were compared with the total population of male births during the same period.

SUBJECTS

2861 cryptorchid boys born in Sweden between 1973 and 1982 were identified. Of these 437 could not be linked with their Medical Birth Registry information for various reasons, or were excluded because they were under 1 year of age at the end of 1982, leaving 2424 cases for study. The reference population comprised all boys born in Sweden during the same period (n = 458,601).

MEASUREMENTS AND MAIN RESULTS

For each study variable, the observed number of cases among boys with cryptorchidism was compared with the expected number calculated from the whole population. A significant increase in intensity ratio for cryptorchidism was found with the first birth, caesarean section, toxaemia of pregnancy, and certain congenital abnormalities (hypospadias and subluxation of the hip). It was also more common in small for dates infants. There was a seasonal variation in cryptorchidism, with increased incidence in January-March.

CONCLUSIONS

Cryptorchidism may be caused by hormonal influences during pregnancy, which could be affected by utero-placental factors involving placental dysfunction or by daylight hours, through pineal activity.

Cancer of the testis and month of birth

It has recently been reported that a series of testis cancers shows a temporal cycle in birth dates with a peak in certain months. This observation has been tested by an examination of a larger series covering all testis cancers diagnosed in the years 1971-84 in England and Wales, in men born in 1940 or later. Limited evidence was found of a 4-monthly cycle, but this was due to a 2-monthly cycle shown by teratomas in men born in the years 1945-49. No evidence was found for such a cycle outside this period, nor for a peak in any particular month.

An approximation for the distribution of the scan statistic

The scan statistic evaluates whether an apparent cluster of disease in time is due to chance. The statistic employs a 'moving window' of length w and finds the maximum number of cases revealed through the window as it scans or slides over the entire time period T. Computation of the probability of observing a certain size cluster, under the hypothesis of a uniform distribution, is infeasible when N, the total number of events, is large, and w is of moderate or small size relative to T. We give an approximation that is an asymptotic upper bound, easy to compute, and, for the purposes of hypothesis testing, more accurate than other approximations presented in the literature. The approximation applies both when N is fixed, and when N has a Poisson distribution. We illustrate the procedure on a data set of trisomic spontaneous abortions observed in a two year period in New York City.

Seasonal variations in cryptorchidism

The month of birth of boys undergoing orchidopexy in the Oxfordshire Health District during the years 1974-83 was analysed. A significant seasonal variation with a peak in April was found for those boys operated upon by paediatric surgeons at a young age (0-4). Possible causes of this variation and its relationship to the aetiology of cryptorchidism are discussed.

Month of birth of men with malignant germ cell tumours of the testis

A recent paper has suggested that there is a temporal cycle in birth rates of men with testis cancer with a peak in April/May. We have investigated the suggestion using data from the South Thames and Los Angeles cancer registries. There is some slight evidence of a peak in August, which is confined to teratomas. The effects demonstrated are, however, too small and inconsistent to provide any real clue to the aetiology of testis cancer.