Incidence rates of testicular cancer are increasing among postpubescent men. This suggests that putative exposures may operate early in life and have changed over time. The age at which endocrine activity accelerates (age at puberty) may be such an exposure. This study was undertaken to investigate the relationship between age at puberty and testicular cancer risk.
A population-based case-control study was conducted in the province of Ontario, Canada which included males, aged 16 to 59 years, diagnosed with testicular germ cell cancer between 1987 and 1989, and age-matched controls. Data were collected on 502 cases, 346 case mothers, 975 controls, and 522 control mothers. Surrogate measures for age at puberty included age at starting to shave, appearance of hair, growth spurt, and voice change.
A protective effect of later puberty was evident for all four measures of puberty as reported by both subjects and mothers, and greater protection was conferred when the greatest number of later puberty events were reported. Risk associated with earlier puberty was inconclusive.
As age at puberty is decreasing in the population, the proportion of boys experiencing the protective effect of later puberty may be diminishing. This may help explain the increasing incidence of testicular cancer.
To examine the pattern of testicular cancer incidence by age, time period and birth cohort since 1969 in Canada.
In addition to analyses of the secular trends by age group and birth cohort separately, an age-period-cohort model and the submodels with standard Poisson assumptions were fitted to the data.
The overall age-adjusted incidence of testicular cancer increased in Canada, from 2.8 per 100,000 males in 1969-71 to 4.2 in 1991-93. The younger age groups showed much higher absolute incidence rates in the recent period compared with those in the early period. Age-period-cohort modelling of data restricted to males aged 20-84 years suggested that the observed increase in testicular cancer could be largely attributed to a birth cohort effect. A steady increase in risk was observed among men born since 1945; those born between 1959 and 1968 were 2.0 (95% CI, 1.5-2.6) times as likely to develop testicular cancer as those born between 1904 and 1913.
The risk of testicular cancer has increased over time and changing exposure to environmental factors early in life may be responsible for this.
To explore the etiology of testicular cancer, cases of testicular cancer were identified among members of a cohort of Danish boys born between 1941 and 1957 (inclusive), who had attended schools in Copenhagen and Gentofte and whose school health records were contained in an archive under the supervision of the Danish Cancer Registry. One hundred and eighty-three cases of testicular cancer diagnosed before 31 December 1984 were identified; 366 controls, matched to cases by sex and age, were selected from the same cohort. Information on potential risk factors and confounders was obtained from two sources: school health records and midwife protocols, both of which were recorded prior to the diagnosis of testicular cancer in cases. Relative risks (RR) approximated by the odds ratios were calculated and, in logistic regression analyses, adjustments were done for known or suspected confounders. A decreasing risk of testicular cancer with increasing birth order was observed (P = 0.020). Compared with being firstborn, being number four or more in birth order was associated with a significantly decreased RR for all testicular cancers (RR = 0.3, 95 percent confidence interval [CI] = 0.3-0.8) and testicular seminoma (RR = 0.1, CI = 0.02-0.9). No association was observed between high social class and the risk of testicular cancer (RR = 1.4, CI = 0.8-2.3); neither was age at which the study subjects had mumps or measles related to risk of testicular cancer. No cases of mumps orchitis were observed before or during school years. A slightly increased RR for testicular cancer among boys from small families could be explained by the association between family size and birth order.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVE: A positive association has been reported between adult height and the incidence of testicular cancer. No previous study has explored whether this relationship is due to the influence of fetal growth on adult height. METHODS: This research question was studied in a Swedish national cohort comprising 337,249 males born 1973-1980 and followed-up for a mean of 4.8 years after army medical conscription examination. Cases of testicular cancer were ascertained from the Swedish National Cancer Register. 144 cases of testicular cancer (120 non-seminomas) diagnosed after conscription were identified. RESULTS: Positive associations were found between height at age 18 years and the incidence of testicular cancer. No associations were observed between gestational age adjusted birthweight and cancer incidence. The positive association between height and cancer incidence was not attenuated in models controlling for birth weight. CONCLUSIONS: Factors influencing post-natal growth such as diet or growth related genes might underlie the association between height and cancer.
Firefighters are potentially exposed to a wide range of known and suspected carcinogens through their work. The objectives of this study were to examine the patterns of cancer among Nordic firefighters, and to compare them with the results from previous studies.
Data for this study were drawn from a linkage between the census data for 15 million people from the five Nordic countries and their cancer registries for the period 1961-2005. SIR analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates.
A total of 16 422 male firefighters were included in the final cohort. A moderate excess risk was seen for all cancer sites combined, (SIR=1.06, 95% CI 1.02 to 1.11). There were statistically significant excesses in the age category of 30-49 years in prostate cancer (SIR=2.59, 95% CI 1.34 to 4.52) and skin melanoma (SIR=1.62, 95% CI 1.14 to 2.23), while there was almost no excess in the older ages. By contrast, an increased risk, mainly in ages of 70 years and higher, was observed for non-melanoma skin cancer (SIR=1.40, 95% CI 1.10 to 1.76), multiple myeloma (SIR=1.69, 95% CI 1.08 to 2.51), adenocarcinoma of the lung (SIR=1.90, 95% CI 1.34 to 2.62), and mesothelioma (SIR=2.59, 95% CI 1.24 to 4.77). By contrast with earlier studies, the incidence of testicular cancer was decreased (SIR=0.51, 95% CI 0.23 to 0.98).
Some of these associations have been observed previously, and potential exposure to polycyclic aromatic hydrocarbons, asbestos and shift work involving disruption of circadian rhythms may partly explain these results.
Comment In: Occup Environ Med. 2014 Aug;71(8):525-624996680
Evidence suggests that fish-derived omega-3 polyunsaturated fatty acids inhibit cancer promotion and progression. On the other hand, fish may contain endocrine-disrupting and potentially carcinogenic environmental contaminants. Our objective was to describe cancer incidence among the Finnish professional fishermen and their wives who are presumed to eat a lot of fish, partly from the contaminated Baltic Sea. Additionally, we wanted to see whether occupational characteristics are reflected in the fishermen's cancer pattern.
All Finnish fishermen during 1980-2002 were identified from the Professional Fishermen Register (n = 6,410) and their wives from the National Population Information System (n = 4,260). The cohort was linked with the Finnish Cancer Registry data until 2011, and the standardized incidence ratios (SIR) were calculated based on national incidence rates.
The total cancer incidence among the fishermen and their wives was the same as in the Finnish general population. Among the fishermen, the incidence was increased for lip (SIR 2.17, 95 % confidence interval 1.26-3.47) and testis (2.51, 1.15-4.75) and decreased for colon (0.72, 0.52-0.98) cancers.
We cannot exclude the possibility that the observed excess in testis cancer among the fishermen could reflect life-long high exposure to environmental contaminants. An excess in lip cancer has been repeatedly observed among outdoor workers due to high exposure to ultraviolet radiation, whereas high physical activity during fishing is the most likely explanation for the deficit in colon cancer.
Individuals with Down syndrome (DS) have a predisposition to leukaemia and testicular cancer, but data on the incidence of cancers are yet sparse. A cohort of 3,581 persons with DS was identified from a National Registry of Finnish persons with intellectual disability collected between 1978 and 1986 and followed-up for cancer incidence until 2002. Standardised incidence ratios (SIRs) were defined as ratios of observed number of cancer cases to those expected from the national cancer incidence rates, by age and sex. The overall cancer risk was equal to that of the general population, but a significantly high risk of leukaemia (SIR 10.5, CI 95% 6.6-15.8) and testicular cancer (SIR4.8, CI 95% 1.8-10.4) was found.
The purpose of this study was to determine the relation between testicular cancer and cigarette smoking. Data were collected between 1995 and 1996 in Ontario, Canada, as part of the Enhanced Cancer Surveillance Study. Pack-years and years of smoking were examined among all subjects (212 cases and 252 controls) and former and current smokers. Years since quitting and age at smoking initiation were examined among former and current smokers only. Independent of smoking status, significant associations were noted among those who smoked between 12 and 24 pack-years [odds ratio (OR) = 1.96 (95% confidence interval (CI): 1.04-3.69), relative to nonsmokers] or greater [>24 pack-years, OR = 2.31 (95% CI: 1.12-4.77), relative to nonsmokers], and among those who smoked >21 years [OR = 3.18 (95% CI: 1.32-7.64), relative to nonsmokers]. Quitting smoking was not found to result in a reduction of risk. No association was observed for smoking at adolescence relative to a later period. Results from the study suggest that cigarette smoking exerts an adverse influence on testicular cancer risk that is not mitigated by smoking cessation and not altered by age at initiation.
The descriptive epidemiology of testicular cancer in Denmark shows that the incidence of both seminoma and non-seminoma has increased gradually since the 1940s to the present. The age-incidence pattern has remained unchanged, and is the same in the Nordic countries despite variation in the overall incidence level. Men born during the early 1940s have a lower risk in all age groups than expected from the overall trend in incidence. These observations support the idea that the occurrence of testicular cancer (both seminoma and non-seminoma) is determined early in life, and most probably before birth. Once the carcinogenic process is established, the age of occurrence of cancer or the histological type of the cancer does not seem to depend upon external factors.