The incidence of testicular cancer was examined in the Nordic and Baltic countries, Poland and Germany by collaboration among 10 cancer registries. Population-based registers were used to analyze a total of 34,309 cases, diagnosed from the start of registration (varying from 1943 in Denmark to 1980 in Latvia and Lithuania) through 1989. An approximately 10-fold geographical variation was found in 1980, with the highest age-standardized incidence rate (7.8 per 10(5); world standard population) in Denmark and the lowest (0.9) in Lithuania. During the entire period of registration, incidence increased rapidly in all countries, by 2.3 to 3.4 per cent annually in the Nordic countries and by about 5 per cent in Poland and Germany; there was some evidence of a slower increase in Denmark and Poland after 1975. The rising trend was more pronounced for ages below 30. The age-specific incidence peaked in all countries at ages 25 to 34, but the geographical variation was considerable. Our data indicate that environmental influences on testicular cancer are strong. Exposure to causal factors mostly takes place early in life, shows substantial geographical variation, and increases over time, so that the age-standardized incidence doubles every 15 to 25 years. New aetiological hypotheses are needed to accommodate these salient features of the descriptive epidemiology, since risk factors considered so far cannot explain the observed pattern.

Testicular cancer in nine northern european countries

Background: For unknown reasons, the age-standardized incidence of testicular cancer has shown a rapid increase in virtually all countries (mostly Western) studied. For populations with a sufficiently long period of cancer registration, this development c

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Increase in Testicular Cancer Incidence in Six European Countries: a Birth Cohort Phenomenon

Objective : To determine the risk of testicular cancer associated with undescended testis, inguinal hernia, age at puberty, marital status, infertility, vasectomy, and amount of exercise. Design : A population based case-control study with a questionnaire administered by an interviewer and with relevant supplementary data extracted from general practioners9 notes. Setting : Nine health regions within England and Wales. Subjects : 794 men, aged 15-49 years, with a testicular germ cell tumour diagnosed between 1 January 1984 and 1 January 1987; each had an age matched (within one year) control selected from the list of their general practioner. Results : There was a significant association of testicular cancer with undescended testis (odds ratio 3.82; 95% confidence interval 2.24 to 6.52) and inguinal hernia (1.91; 1.12 to 3.23). The excess risk associated with undescended testis was eliminated in men who had had an orchidopexy before the age of 10 years. There were positive associations with earl age at voice breaking, early age at starting to shave, and infertility. There was a significant association with a sedentary lifestyle and a moderate protective effect of exercise. There was no association with vasectomy. Conclusion : This study confirms previous reports that developmental urogenital abnormalities result in an increased risk of testicular cancer. The trend to perform orchidopexy at younger ages may reduce the risk associated with undescended testis. The increased risks associated with early age at puberty and low amounts of exercise may be related to effects of exposure to endogenous hormones. Changes in both of these factors may partly contribute to the increasing rates of testicular cancer observed in the past few decades.

Aetiology of testicular cancer: association with congenital abnormalities, age at puberty, infertility, and exercise

Clinical epidemiology is sometimes called the basic science of clinical medicine. In terms of the pathogenesis of testicular germ cell tumors (GCTs), clinical epidemiology analyzes suspected risk factors. The present review highlights the risk factors established so far and briefly summarizes those factors currently under investigation. In analogy to the methods of evidence based medicine, this review attributes levels of evidence to each of the putative risk factors. Level I represents highest quality of evidence while level V denotes the lowest level. So far, undescended testis (UDT), contralateral testicular GCT and familial testis cancer are established risk factors attaining high levels of evidence (levels I–III a). In a meta-analysis of 21 studies exploring the association of UDT with GCT risk, an over-all relative risk (RR) of 4.8 (95% confidence interval 4.0–5.7) was found. Contralateral testicular GCT involves a roughly 25-fold increased RR of GCT, while familial testis cancer constitutes a RR of 3–10. Infertility, testicular atrophy, and twin-ship represent risk factors with lesser levels of evidence (level III a). There is also some evidence for HIV infection being a predisposing factor for GCT (level IV a). Scrotal trauma is probably not associated with GCT risk. The estrogen excess theory implies high estrogen levels during the first trimester of pregnancy. As a consequence, primordial germ cells lose track of the normal developmental line and transform into premalignant cells that later become testicular intraepithelial neoplasia (TIN), the precursor of full-blown testicular GCT. Surrogate parameters for high gestational estrogen levels are investigated in case control studies. Such factors are maternal age >30 years, first-born, low birth weight, maternal breast cancer, high sex-ratio of siblings. So far, the sum of evidence is promising but still conflicting (especially for level III b). Another novel theory is the childhood nutrition hypothesis. This concept postulates a modulating or “catalyzing” effect by high dietary intake during childhood on the pathogenesis of testicular GCT. A surrogate parameter of early childhood nutrition is adult height. So far, 12 controlled studies have looked to the possible association of attained height and GCT risk of which six demonstrated a significant association. Thus, the sum of evidence corresponds to level III b. This concept is appealing because it would explain several hitherto unexplained epidemiological features of GCT.

Clinical epidemiology of testicular germ cell tumors.

To explore risk factors for testicular cancer and cryptorchidism, two parallel case-control studies were conducted in Denmark. The testicular cancer study was population-based and included 514 cases and 720 controls. The cryptorchidism study included 387 cases and 416 controls and was based on two hospital series of men treated for cryptorchidism and a control group sampled among residents in the Copenhagen area. The 2,037 men were interviewed by telephone. The relative risk (RR) of testicular cancer in men with treated or persisting cryptorchidism was 3.6 (95 percent confidence interval = 1.8-6.9), but no increase in risk was seen in the six to seven percent of the men who reported a history of undescended testes that descended spontaneously. The RR in men who were treated for cryptorchidism increased with age at treatment. This effect may be due wholly or in part to increased treatment of boys with testes that would have descended spontaneously if they had not been treated. Cryptorchidism and inguinal hernia may be confused and reported interchangeably. In the absence of cryptorchidism or testicular atrophy, clinical inguinal hernia was not associated with testicular cancer. Testicular atrophy was associated with both testicular cancer and cryptorchidism. Associations with other congenital malformations were few and based on small numbers.

Møller H

Papers

Aetiology and epidemiology of testicular cancer: report of consensus group.