Time trends and occupational differences in cancer of the testis in New Zealand

Smart Intravenous Infusion Dosing System

Intravenous (IV) infusion therapy allows the infusion fluid to be inserted directly into the patient’s vein. It is used to place medications directly into the bloodstream or for blood transfusions. The probability that a hospitalized patient will receive some kind of infusion therapy, intravenously, is 60–80%. The paper presents a smart IV infusion dosing system for detection, signaling, and monitoring of liquid in an IV bottle at a remote location. It consists of (i) the sensing and computation layer—a system for detection and signaling of fluid levels in the IV bottle and a system for regulation and closing of infusion flow, (ii) the communication layer—a wireless exchange of information between the hardware part of the system and the client, and (iii) the user layer—monitoring and visualization of IV therapy reception at a remote location in real time. All layers are modular, allowing upgrades of the entire system. The proposed system alerts medical staff to continuous and timely changes of IV bottles, which can have positive effects on increasing the success of IV therapy, especially in oncology patients. The prescribed drip time of IV chemotherapy for the full effect of cytostatics should be imperative.

Future of testicular germ cell tumor incidence in the United States: Forecast through 2026

BACKGROUND

Testicular germ cell tumors (TGCTs) are rare tumors in the general population but are the most commonly occurring malignancy among males between ages 15 and 44 years in the United States (US). Although non-Hispanic whites (NHWs) have the highest incidence in the US, rates among Hispanics have increased the most in recent years. To forecast what these incidence rates may be in the future, an analysis of TGCT incidence in the Surveillance, Epidemiology, and End Results program and the National Program of Cancer Registries was conducted.

METHODS

TGCT incidence data among males ages 15 to 59 years for the years 1999 to 2012 were obtained from 39 US cancer registries. Incidence rates through 2026 were forecast using age-period-cohort models stratified by race/ethnicity, histology (seminoma, nonseminoma), and age.

RESULTS

Between 1999 and 2012, TGCT incidence rates, both overall and by histology, were highest among NHWs, followed by Hispanics, Asian/Pacific Islanders, and non-Hispanic blacks. Between 2013 and 2026, rates among Hispanics were forecast to increase annually by 3.96% (95% confidence interval, 3.88%-4.03%), resulting in the highest rate of increase of any racial/ethnic group. By 2026, the highest TGCT rates in the US will be among Hispanics because of increases in both seminomas and nonseminomas. Rates among NHWs will slightly increase, whereas rates among other groups will slightly decrease.

CONCLUSIONS

By 2026, Hispanics will have the highest rate of TGCT of any racial/ethnic group in the US because of the rising incidence among recent birth cohorts. Reasons for the increase in younger Hispanics merit further exploration. Cancer 2017;123:2320-2328. © 2017 American Cancer Society.

Adolescent and adult risk factors for testicular cancer

The incidence of testicular cancer has been increasing over the past several decades in many developed countries. The reasons for the increases are unknown because the risk factors for the disease are poorly understood. Some research suggests that in utero exposures, or those in early childhood, are likely to be important in determining an individual's level of risk. However, other research suggests that exposure to various factors in adolescence and adulthood is also linked to the development of testicular cancer. Of these, two adult occupational exposures-fire fighting and aircraft maintenance--and one environmental exposure (to organochlorine pesticides) are likely to be associated with increased risk of developing testicular cancer. By contrast, seven of the identified factors--diet, types of physical activity, military service, police work as well as exposure to ionizing radiation, electricity and acrylamide--are unlikely to increase the risk of developing testicular cancer. Finally, seven further exposures--to heat, polyvinyl chloride, nonionizing radiation, heavy metals, agricultural work, pesticides and polychlorinated biphenyls as well as marijuana use--require further study to determine their association with testicular cancer.

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.

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.

[Metachronous testicular seminoma with an interval of 14 years from the first nonseminomatous testicular tumor: a case report]

A 32-year-old man was admitted to our hospital with a complaint of right scrotal swelling. He had a past history of left testicular nonseminomatous germ cell tumor (NSGCT), stage IIB 14 years ago. He had undergone chemotherapy with 3 courses of PEP and retroperitoneal lymphnode dissection revealing pathological CR. He was diagnosed as having right testicular tumor. He underwent right high orchiectomy. Imaging studies and pathological studies revealed pure seminoma with spermatic cord invasion, stage I, pT3N0M0. He underwent chemotherapy with 3 courses of VIP. Herein we present a case of metachronous bilateral testicular germ cell tumor with a review of literatures.

Testicular cancer incidence trends in the USA (1975-2004): plateau or shifting racial paradigm?

OBJECTIVE

It has been reported that the incidence of testicular cancer has plateaued in some parts of the USA, especially among non-Hispanic Whites in Los Angeles. Temporal trends analysis was conducted over three decades to assess the evidence for such a plateau, and to examine whether the incidence of testicular cancer remains stable across racial/ethnic groups. This study also investigated the influence of age at diagnosis on the incidence of testicular cancer.

STUDY DESIGN

Population-based temporal trends analysis.

METHODS

Using the Surveillance Epidemiology and End Results (SEER), 16,580 newly diagnosed cases of testicular cancer in males aged 15-49 years were identified between 1975 and 2004. Incidence rates were examined by calculating the age-adjusted rates and their 95% confidence interval (CI) for age at diagnosis, SEER areas and race for the year of diagnosis. The percentage change and annual percentage change were examined for trends.

RESULTS

The incidence of testicular cancer is continuing to increase among US males, despite the plateau of the 1990s. Between 1975 and 2004, the age-adjusted incidence rate for males aged 15-49 years increased from 2.9 (1975) to 5.1 (2004) per 100,000. The trends indicated a percentage change of 71.9% and a statistically significant annual percentage change of 1.6% (95%CI 1.3-2.0; P<0.05). Although the incidence of testicular cancer in Blacks remained strikingly low (0.3-1.4 per 100,000), the highest annual percentage change was observed among this group (2.3%, 95%CI 0.8-3.9; P<0.05 for trends). The rates were intermediate among Asians/Pacific Islanders and American Indian and Alaska Natives (0.7-2.9 per 100,000), with a percentage change of 117.3% and a statistically significant annual percentage change of 1.5% (95%CI 0.3-2.7; P<0.05 for trends). The highest rates were reported among Whites (3.2-6.3 per 100,000), with a percentage change of 90.4% and a statistically significant annual percentage change of 2.0% (95%CI 1.6-2.3; P<0.05). The most common age at diagnosis was 30-34 years, while the lowest rates were reported in those aged 15-19 years. Likewise, incidence rates varied by SEER areas, with predominantly White states representing areas associated with the highest reported rates of testicular cancer.

CONCLUSIONS

Overall, the incidence of testicular cancer continues to plateau in the USA, while racial variance persists. Black males demonstrate the greatest increase in annual percentage change. Further studies are needed to examine the recent increase among Black males and the potential determinants.

A comprehensive systematic review of testicular germ cell tumor surveillance

BACKGROUND

Testicular cancer is the most common malignancy in men aged 15-34, and its incidence has been increasing over the past half-century. Survival for stage I testis cancer approaches 100% regardless of management strategy which is often dictated by other factors such as perceived morbidity. Advances in treatment have attempted to decrease morbidity and surveillance is thought to achieve this goal.

METHODS

An English language literature search of MEDLINE from 1966 to December 2005 and CINAHL from 1982 to December 2005 was conducted using a broad search strategy. Comparative and descriptive original articles on outcomes of seminoma or NSGCT surveillance would be deemed eligible and review articles containing no original data were omitted. One hundred and thirty-eight articles were selected for formal review, during which a database was compiled that documented the first author, publication year, tumor histologic type, study purpose or topic(s), methodology, sample size, median follow-up, and relevant results.

RESULTS

Most evidence for the efficacy of surveillance is from descriptive series or non-experimental comparative studies. Relapse occurs in approximately 28% and 17% of surveillance patients in NSGCT and seminoma, respectively, and cause-specific survival is approximately 98% and 100%, respectively. Compliance with surveillance ranges from poor to adequate, however there is no evidence that compliance impacts clinical outcome. Cost analyses have yielded inconsistent results when comparing treatment modalities. There is scant literature on quality of life and psychosocial issues and results are inconsistent. Active surveillance appears to be appropriate and perhaps optimal first line management of clinical stage I seminoma and non-seminomatous germ cell tumors. Further quantitative and qualitative research is warranted to deepen understanding of these issues that may impact treatment decision-making.

Do testicular seminoma and nonseminoma share the same etiology? Evidence from an age-period-cohort analysis of incidence trends in eight European countries

The incidence of the two main clinical subentities of testicular germ cell cancer (seminoma and nonseminoma) is increasing throughout Europe. Most studies have revealed little variation in risk factors between the two subtypes. This study compared generation-specific trends in eight European countries, hypothesizing that similar temporal pattern by birth cohort implied that seminoma and nonseminoma had a largely comparable etiology. The results are presented using the age-period-cohort model and the nonidentifiability problem highlighted by partitioning the age, period, and cohort effects in terms of their linear and curvature component parts, assuming a priori that cohort effects predominated. Despite uniform overall increases by calendar period, declining rates of nonseminoma but not pure seminoma were observed in the majority of countries during the 1990s. The subtype trends were, however, largely analogous on a birth cohort scale. Notable observations were a decline in rates of both subtypes among recent birth cohorts in Switzerland and a short-term wartime effect in several countries, involving an attenuation of increasing risk of both subtypes in men born in 1940 to 1945. Departures from the steady increases in testicular cancer over time were likely to occur for nonseminomas some years ahead of seminoma on a period scale. The importance of birth cohort coincided with the view that given a short time interval of susceptibility to exposures earlier in life and a biologically constant time to diagnosis, all temporal changes in rate-limiting exposures should appear as generational effects. Trends in seminoma and nonseminoma conform to largely the same temporal patterns on this scale, implying that they share important etiologic factors.

Epidemiological pattern and time trends in testicular germ-cell tumors: a single institution 20-year experience

INTRODUCTION

Recent studies have suggested a rise in the incidence of testicular germ-cell tumors (TGTs) in the last years, mainly due to an increase of early stage cases. We analysed the time trends in biological features of these patients in order to confirm this tendency in our environment.

MATERIALS AND METHODS

The clinical records of 136 consecutive patients with TGTs treated at a single institution over a 20-year period (1984-2003) were retrospectively reviewed. Pathological, clinical, therapeutic and outcome data were collected. Patients were allocated into four consecutive 5- year intervals and their characteristics were compared by means of the chi-squared test. The survival analysis was performed with the method of Kaplan and Meier.

RESULTS

A progressive increase in the incidence of new cases, and a more frequent diagnosis of stage I versus stage II-IV disease was confirmed within this time period. It was also observed a greater use of postorchiectomy chemotherapy, mainly due to an increase in the adjuvant indications. A significant decrease in the recurrence rate was noted. Ten-year overall survival was 86.5%. There was a trend for improved outcome, but the differences among the two decades were not statistically significant.

CONCLUSIONS

A real increase in the incidence of TGTs and in the proportion of early stages was confirmed. This may be due to an epidemiological change or to an earlier diagnosis. This new pattern is associated with a more frequent use of adjuvant chemotherapy and with a reduction in the relapse rate.

Incidence and survival rates for female malignant germ cell tumors

OBJECTIVE

To evaluate 30-year, population-based trends in incidence and survival rates for malignant germ cell tumors originating within the female genital tract.

METHODS

Surveillance, Epidemiology, and End Results data were used to identify malignant germ cell tumors (1973-2002). Overall and 5-year incidence rates, estimated annual percentage change, and survival rates were calculated and compared by age at diagnosis, race, stage, and histology.

RESULTS

Of 1,262 cases, there were 414 (32.8%) dysgerminomas, 449 (35.6%) immature teratomas, 37 (2.9%) mature teratomas with malignant degeneration, and 362 (28.7%) mixed germ cell tumors. The 30-year, age-adjusted incidence rate per 100,000 women-years was 0.338, decreasing by 29.4% for dysgerminomas (P = .18) and by 31.5% for mixed germ cell tumors (P = .22). Other nonwhites had higher rates than whites and blacks, but dysgerminoma rates were higher in whites and other nonwhites than in blacks. Using the registries for expanded races, rates were higher for Asian/Pacific Islanders (P = .059) and Hispanics (P = .07). By age at diagnosis, 15-19 year olds had the highest rates and the only significant change in rates (37.5% increase, P = .008). The 5-year relative survival was 83.9%. Survival rates improved significantly over calendar time and varied by histologic subtype, race, stage of disease, and age at diagnosis.

CONCLUSION

Over the past 30 years, germ cell tumor incidence rates have declined in women and differ from rising trends reported for testicular tumors. Survival rates have improved but were lower for older women and for nondysgerminoma subtypes.

Testicular cancer, occupation and exposure to chemical agents among Finnish men in 1971-1995

OBJECTIVE

To find associations between testicular cancer, occupation and chemical exposure.

METHODS

A cohort of all economically active Finnish men born between 1906 and 1945 was followed-up for 19.7 million person-years during 1971-1995. Incident cases of testicular cancer (n=387) were identified in a record linkage with the Finnish Cancer Registry. The Census occupations in 1970 were converted to chemical exposures with a job-exposure matrix (FINJEM). Cumulative exposure (CE) was calculated as the product of prevalence, level, and duration of the exposure. Standardised incidence ratio (SIR) was calculated for each of the 393 occupations, and for CE categories of the 43 chemical agents, using average male population as reference. Relative risks (RR) comparing various CE-categories with unexposed ones were defined for selected agents by Poisson regression analysis.

RESULTS

Elevated SIRs were observed among railway traffic supervisors (5.8, 95% CI 1.6-14.7), programmers (4.3, 1.4-9.9), university teachers (4.1, 1.3-9.5) and electrical engineers (3.9, 1.1-10.1). A significant exposure-response trend (mainly contributed by seminoma) was observed for pesticides, textile dust, aliphatic and alicyclic hydrocarbons, and some other organic solvents.

CONCLUSIONS

Risk of testicular cancer increased only in four occupations. Pesticides, textile dust, and some organic solvents may be related to an excess risk of seminoma.

International patterns and trends in testis cancer incidence

Although the incidence of testis cancer has risen markedly in many Western populations over the past half-century, it is not clear whether rates in other populations also have increased. To clarify this issue, we examined testis cancer incidence rates over the 25-year time period of 1973-1997 for selected populations around the world. Age-standardized incidence rates for 21 registries in the Americas, Asia, Europe and Oceania over successive 5-year time periods were obtained from volumes 4-8 of Cancer Incidence in Five Continents. Testis cancer rates rose between 1973 and 1997 in most populations worldwide, although the increases were strongest and most consistent among populations of European ancestry. Rates appear to be leveling off in some populations. The increases in testis cancer remain unexplained, although changes in the prevalence of important risk factors for this disease may be responsible.

Residential exposure to overhead high-voltage lines and the risk of testicular cancer: results of a population-based case-control study in Hamburg (Germany)

BACKGROUND

In a population-based case-control study we examined the association between residential exposure to overhead high-voltage lines and testicular cancer.

METHODS

We recorded the residential biography of cases with testicular cancer identified by the Hamburg Cancer Registry and of controls that were randomly selected from the mandatory registry of residents in Hamburg. The study included 145 incident cases between 15 and 69 years of age, diagnosed between 1995 and 1997, and 313 controls, matched for age in 5-year strata. In model A, exposure was defined by distance (ever vs never). Model B took into account residence time and the inverse distance from the nearest high-voltage line. It distinguished between low and high exposure, the never exposed persons serving as a reference group. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by unconditional logistic regression. For men below the age of 40 years and men aged 40 years and over separate analyses were carried out.

RESULTS

Within a corridor of 100 m the prevalence of exposure to high-voltage lines in Hamburg was 6.9% in cases and 5.8% in controls (OR=1.3; 95% CI=0.56-2.80). In the more complex model B we found an OR of 1.2 (95% CI=0.60-2.47) for low exposure and 1.7 (95% CI=0.91-3.32) for high exposure. Younger men show slightly increased risks in both models.

CONCLUSIONS

In all, residential exposure to high-voltage lines did not seem to be a major risk factor for testicular cancer in our study. Yet, the fact that risks for men below the age of 40 years were slightly increased in both exposure models deserves further attention.

Testicular Cancer Incidence in Eight Northern European Countries: Secular and Recent Trends

Objective: Striking geographic variation and marked increasing secular trends characterize the incidence of testicular cancer. However, it is not known whether these patterns have attenuated in recent years and whether they are similar for seminomas and nonseminomas, the two main histologic groups of testicular cancer.

Method: Cancer registry data, including 27,030 testicular cancer cases, were obtained from Denmark, Estonia, Finland, Latvia, Lithuania, Norway, Poland, and Sweden. Between 57 (Denmark) and 9 (Poland) years of registration were covered. Country-specific temporal trends were estimated, with focus on the last decade and seminomas and nonseminomas. Data from the Nordic countries were further analyzed using an age-period-cohort approach.

Results: Age-standardized incidence rates increased annually by 2.6% to 4.9% during the study period, with marginal differences between seminomas and nonseminomas. In the last decade, the increasing trend attenuated only in Denmark (annual change, −0.3%; 95% confidence interval, −1.5 to 0.9). In 1995, the highest and the lowest age-standardized incidence rates (per 105) were 15.2 in Denmark and 2.1 in Lithuania. Incidence rates (i.e., for all cancers and for seminomas and nonseminomas, separately) depended chiefly on birth cohort rather than on calendar period of diagnosis (although both birth cohort and period determined the Danish incidence rates).

Conclusions: Testicular cancer incidence is still increasing, with the exception of Denmark, and a large geographic difference exists. The increasing trend is mainly a birth cohort phenomenon also in recent cohorts. Temporal trends for seminomas and nonseminomas are similar, which suggests that they share important causal factors.

Birth Order, Sibship Size, and Risk for Germ-Cell Testicular Cancer

BACKGROUND

Several studies have reported an inverse association between birth order and testicular cancer risk, but estimates vary greatly and the biologic mechanism underlying the association is not established.

METHODS

We have evaluated the effect of birth order, sibship size, and the combined effect of these 2 variables in relation to risk for testicular cancer in a large, nested case-control study. Specifically, we compared 3051 patients with germ-cell testicular cancer (diagnosed between 1958 and 1998 and identified through the Swedish Cancer Registry) with 9007 population control subjects. Using record linkage with the Multi-Generation Register and the Census, we obtained information on number, order, and sex of the subjects' siblings, parental age, and paternal socioeconomic status.

RESULTS

Both birth order and sibship size had an inverse and monotonically decreasing association with testicular cancer risk after adjusting for parental age, paternal socioeconomic status, and twin status. The associations were modified by subjects' cohort of birth and were not present among those born after 1959. The odds ratio for having at least 3 siblings, compared with none, was 0.63 (95% confidence interval = 0.53-0.75) among subjects born before 1960. Stratified analyses showed that birth order and number of younger siblings had a similar inverse association with the risk for testicular cancer.

CONCLUSIONS

Sibship size, and not only birth order, is associated with testicular cancer risk. This suggests a higher prevalence of parental subfertility among patients with testicular cancer.

Clinical epidemiology of testicular germ cell tumors

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.

Trends in the incidence of testicular germ cell tumors in the United States

BACKGROUND

Recent reports have suggested that the increasing rates of testicular germ cell tumors in some populations have begun to plateau. This study was conducted to examine whether rates among white men in the United States have begun to stabilize and whether rates among black men in the United States have remained low.

METHODS

Testicular germ cell tumor incidence data from in the Surveillance, Epidemiology, and End Results Program were analyzed for the years 1973-1998. Trends were examined separately for seminoma and nonseminoma. Using age-period-cohort analyses with 5-year age intervals and 5-year calendar-period intervals, changes in the slope of the trends in birth-cohort and calendar-period effects were examined.

RESULTS

Among white men, rates of seminoma continued to increase, but the rate of increase steadily declined throughout the 26-year time span. Nonseminoma rates among whites increased more slowly during the first three time intervals, then plateaued in the final interval. Rates of both seminoma and nonseminoma in black men fluctuated throughout the first three time intervals. In the final interval, the rates of seminoma increased almost 100%, whereas the rates of nonseminoma increased more modestly. Age-period-cohort modeling of the incidence data in white men found that, whereas the dominant effect was that of birth cohort, there also was a period effect.

CONCLUSIONS

Among white men in the United States, the incidence of testicular germ cell tumors varied by histology, with a continuing increase in risk only for seminoma. Among black men in the United States, the surprising increases seen between 1988 and 1998 were likely to be a calendar-period effect.

Socio-economic differences in incidence rates of cancers of the male genital organs in Finland, 1971-95

We studied social class variation in the incidence of cancers of the prostate, testis, penis and scrotum among 1.1 million Finnish men (45-69 years of age) during 1971-95. The incidence of prostate cancer (6,972 cases) was increasing during the study period; the highest at all the times occurred in Social Class I (highest social class), 40-50% higher than in Social Class IV (lowest). The social class gradient was strongest in localized disease but there was some variation in incidence of non-localized prostate cancer. A total of 174 testicular cancer cases were diagnosed during the study period. In the early 1970s, the incidence of testicular cancer in Social Class I was 5-fold compared to Social Classes III and IV. Thereafter, the incidence rate decreased in Social Class I, but increased in the lower classes. The positive social class gradient was similar for seminomas and non-seminomas. For penile cancer (n = 128), the incidence decreased over time and social class variation was small. Only 6 cases of scrotum cancer were observed. In testicular cancer the strong positive social class association in the early 1970s is disappearing along with converging incidence trend slopes in different social classes. The difference diminished to less than 2-fold in the 1990s. Reasons for this observation remain open.

Incidence of testicular cancer and occupation among Swedish men gainfully employed in 1970

PURPOSE

To estimate occupation-specific risk of seminomas and nonseminoma subtypes of testicular cancer among Swedish men gainfully employed in 1970 over the period 1971-1989.

METHODS

Age-period standardized incidence ratios were computed in a dataset linking cancer diagnoses from the Swedish national cancer register to occupational and demographical data obtained in the census in 1970. Log-linear Poisson models were fitted, allowing for geographical area and town size. Taking occupational sector as a proxy for socioeconomic status, occupational risks were recalculated using intra-sector analyses, where the reference group comprised other occupations in the same sector only. Risk estimators per occupation were also computed for men reporting the same occupation in 1960 and 1970, a more specifically exposed group.

RESULTS

Seminomas and nonseminomas showed a substantial geographical variation. The association between germ-cell testicular tumors and high socioeconomic groups was found mainly for nonseminomas. Positive associations with particular occupations were more evident for seminomas, for which railway stationmasters, metal annealers and temperers, precision toolmakers, watchmakers, construction smiths, and typographers and lithographers exhibited a risk excess. Concrete and construction worker was the only occupation consistently associated with nonseminomas.

CONCLUSIONS

Among the many occupations studied, our results corroborate the previously reported increased risk among metal workers, specifically related with seminomatous tumors in this study. Our results confirm the geographical and socioeconomical differences in the incidence of testicular tumors. These factors should be accounted for in occupational studies. The different pattern of occupations related with seminomas and nonseminomas support the need to study these tumors separately.

Is testicular cancer an occupational disease of fire fighters?

BACKGROUND

A previous investigation showed an increased risk of testicular cancer among fire fighters in Wellington City, New Zealand, during the 1980s. Other studies of fire fighters had not identified testicular cancer as an occupational disease.

METHODS

This was an historical cohort study of mortality and cancer incidence in all paid New Zealand fire fighters, from 1977 to 1995.

RESULTS

The only cancer for which this study provided evidence of an increased risk was testicular cancer, even after excluding cases from the previous investigation. The standardized incidence ratio for 1990-96 was 3.0 (95% confidence interval: 1.3-5.90). There was no evidence that fire fighters were at increased risk from any particular cause of death.

CONCLUSIONS

This study confirmed that New Zealand fire fighters are at increased risk of testicular cancer, although the reason is unknown. Other incidence studies of cancer in fire fighters are needed to confirm this finding.

Increasing incidence of testicular cancer--birth cohort effects

The incidence of testicular cancer is rising in most Western populations. A collaborative study between nine population-based cancer registries in countries around the Baltic Sea was utilized in order to analyze in detail geographic variations and temporal trends in the occurrence of testicular cancer. There were 34,309 cases registered up until 1989 starting in Denmark in 1942 and most recently in Latvia in 1977. From the descriptive epidemiology it was obvious that there was a substantial variation in the age-standardized incidence amounting to about a 10-fold difference between the different countries ranging from 0.8 per 100,000 person-years in Lithuania to 7.6 per 100,000 person-years in Denmark. Previous studies have indicated that this increase is due to birth cohort effects. A more detailed analysis was therefore performed in those six countries with a sufficiently long period of cancer registration; Poland, former East Germany, Norway, Finland, Denmark and Sweden. This analysis showed that birth cohort is a more important determinant of testicular cancer risk than year of diagnosis. In Poland, former East Germany and Finland, there was an increasing risk for all birth cohorts. Among men born in Denmark, Norway or Sweden between 1930 and 1945, this increasing trend in risk was interrupted in these birth cohorts but followed thereafter by an uninterrupted increase by birth cohort. In conclusion, life time exposure to environmental factors which are associated with the incidence of testicular cancer appear to be more related to birth cohort than to year of diagnosis. Because testicular cancer typically occurs at an early age, major etiological factors therefore need to operate early in life, perhaps even in utero.

Baldness and other correlates of sex hormones in relation to testicular cancer

There is evidence that sex hormones and intrauterine factors are involved in the etiology of testicular cancer. We evaluated the importance of perinatal and adult life correlates of sex hormones as risk factors for testicular cancer in a case control study of 97 incident, histologically confirmed cases, residents of the Greater Athens area and environs, who were diagnosed in the 3 specialized cancer hospitals and the major General Hospital in Athens during the 2 year period 1993-94. Cases were age-matched to 2 healthy controls from the same study base. Both cases and controls as well as their mothers were interviewed by the same investigator and the data were analyzed through conditional logistic regression. The odds ratio for testicular cancer was elevated among persons born after a pregnancy characterized by severe nausea. Among the adult life factors, higher body mass was associated with reduced risk, as was evidence of baldness. To the extent that nausea during pregnancy reflects higher levels of pregnancy estrogens on the one hand, and baldness is linked to androgens on the other, our data suggest that estrogens in the intrauterine life and androgens at later stages may have sequential opposing effects for the development of testicular cancer.

Parental occupational exposure and the risk of testicular cancer in Ontario

The incidence of germ cell testicular cancer is increasing, but its etiology remains largely unknown. Initiation may occur in a parental germ cell. In a case-control study in Ontario, jobs and industries of mothers (before and during pregnancy) and fathers (before pregnancy) of 343 case subjects and 524 control subjects were analyzed. Significantly increased risk was associated with fathers who were wood processors (odds ratio [OR] = 10.46; 95% confidence interval [CI], 1.20 to 91.14), metalworkers (OR = 3.28; 95% CI, 1.03 to 10.52), stationary engineers (OR = 1.05; 95% CI, 1.05 to 11.87), or employees of the food products (OR = 2.79; 95% CI, 1.34 to 5.79), metal products (OR = 5.77, 95% CI, 1.53 to 21.77), or food and beverage services (OR = 4.36; 95% CI, 1.50 to 12.63) industries. There was little evidence of risk associated with maternal employment. Paternal employment before conception in jobs related particularly to metal or food and beverages may be related to testicular cancer risk in sons.

Occupation and risk of germ cell testicular cancer by histologic type in Ontario

Incidence of both major histologic subgroups of germ cell testicular cancer, seminoma and nonseminoma, is increasing, but the etiology is largely unknown. Occupational clusters have been observed. In a case-control study in Ontario with 495 incident cases and 974 population control subjects, jobs and industries were coded and analyzed. There is little evidence of occupational risk for all cases or for seminoma. Significantly increased risk of nonseminoma was associated with: miners (odds ratio [OR] = 12.39; 95% confidence interval [CI], 2.22 to 69.27), food and beverage processors (OR = 3.20; 95% CI, 1.39 to 7.35), utilities employees (OR = 3.15; 95% CI, 1.15 to 8.61), and other service workers (OR = 1.05; 95% CI, 1.05 to 4.56). Leather-industry employees had elevated risk of nonseminoma (OR = 4.60; 95% CI, 0.75 to 28.28) consistent with a leather tannery cluster. Increased risk of nonseminoma among some workers can be explained if an additional event is required for converting seminoma to nonseminoma.

Continuing increase in incidence of germ-cell testis cancer in young adults: experience from Connecticut, USA, 1935-1992

The current study is designed to examine long-term trends by histologic types of testis cancer in Connecticut. A regression model was used to identify age, period, or cohort as determinants of the time-trend on histologic types of testis cancer. The results from this descriptive epidemiologic study show that the overall age-adjusted incidence rate of testis cancer has increased 3.5-fold in Connecticut during the past nearly 60 years of cancer registration. The rates for seminoma and non-seminoma have been increasing since the mid-1950s and increase in a similar manner for those aged 15 to 49. The largest increase was observed in the age groups 20 to 44 for seminoma and 15 to 34 for non-seminoma. The observed increase was limited to whites. The results from age-period-cohort modeling suggest that the observed increase in seminoma before 1950s could be largely attributable to a period effect, while the increase for cohorts born after about 1910 both for seminoma and for non-seminoma are mainly explained by a strong birth-cohort effect. Therefore, the observed increase in germ-cell testis cancer in this population is likely to continue in the coming years. Thus far, the proposed hypotheses, such as exposure to DES in utero, earlier lifetime exposure to viruses, trauma or unusual amounts of heat to the testis, cannot adequately explain the observed incidence patterns of testis cancer. Analytical epidemiologic studies with large sample size are urgently needed to examine the risk factors responsible for the increase.

The epidemiology of non-seminomatous germ cell tumours in the west of Scotland 1975-89

A total of 438 males resident in the six West of Scotland Health Board areas were notified to the cancer registry with a diagnosis of teratoma between 1 January 1975 and 31 December 1989. Non-registration was between 2% and 3.4%; a further 44 cases were ascertained through independent listings in the major tertiary referral centres. There were four (1%) duplicate registrations and 16 (4%) were incorrect on the basis of pathology (three) or residence (13). Of these, most (26) were registered with alternative diagnoses and eight were registered on the pre-1985 manual system. The positive correlation between socioeconomic status and incidence was confirmed by linking residential postcode at diagnosis to the Carstairs and Morris Deprivation Index. There was an increasing incidence, both overall and for men aged 15-44 years, with doubling times of 20 and 25 years respectively. The increase was confined to men resident in the more deprived postcode sectors; the incidence rate among men from the most affluent areas remained unchanged throughout the period of study.

Physical activity, medical history, and risk of testicular cancer (Alberta and British Columbia, Canada)

In order to evaluate risk factors for germ cell cancers, we conducted a case-control study of 510 men with testicular cancer aged 15 to 79 years and 996 randomly selected age-matched controls in the provinces of British Columbia and Alberta, Canada. Subjects completed a mailed questionnaire providing data on education level, ethnic origin, medical history, smoking, occupation, and recreational and sports activity. The response rate among cases was 80.3 percent and among controls was 68.1 percent. After controlling for age and ethnic origin, undescended testis was associated positively with risk of testicular cancer (odds ratio [OR] = 3.5; 95 percent confidence interval [CI] = 2.2-5.7) as was inguinal hernia requiring surgery (OR = 2.0, CI = 1.3-2.9), and hydrocoele (OR = 2.6, CI = 1.4-5.1). Risk of testicular cancer increased with height, with subjects taller than 180 cm having a significantly increased risk compared with those 174 cm or less (OR = 1.5, CI = 1.1-2.1). A moderate to high level of recreational activity level was associated inversely with testicular cancer risk (OR = 0.6, CI = 0.5-0.8).

High frequency of metalworkers among patients with seminomatous tumors of the testis: a case-control study

Occupational analyses were conducted between 1971 and 1978 comparing 165 cases of testicular cancer in the Hannover region of Germany with 187 controls without neoplastic diseases admitted to the Hannover University Medical School during the same period. The results showed a significantly higher risk of metal workers developing seminomas and mixed seminomatous tumors compared to the controls (odds ratio 2.05; 1.17-3.58). There was a lack of risk for the nonseminomatous tumors as a whole group, and cases with a history of metal work may have a decreased risk for embryonal carcinomas. No definite single noxious substance responsible for the development of testicular tumors could be detected. In view of the results in animal experiments, cadmium and zinc are especially considered in the discussion.

Testicular cancer in nine northern European countries

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.

Increased incidence of germ cell testicular cancer in New Zealand Maoris

A higher incidence of germ cell testicular cancer was found in Maoris (6.84/100,000) compared with non-Maoris (5.26/100,000) in New Zealand from 1975 to 1986, especially in the 15-49 year age group (Maoris 12.30/100,000, non-Maoris 9.47/100,000; P = 0.04). Previous studies have shown Whites to have the highest incidence of this malignancy. Possible reasons for this and some other epidemiological features are discussed.

Cancer of the testis, socioeconomic status, and occupation

The risk of testicular cancer in relation to lifetime histories of socioeconomic status, occupation, and occupational exposures was examined in a case-control study in England. Interviews were conducted with 259 cases, 238 control patients treated at radiotherapy and oncology centres, and 251 controls who were hospital inpatients in other departments. Risk of testicular cancer was raised in men of high socioeconomic status measured both by occupation and in other ways, and was similar in relation to status measured at birth and at various later stages of life. The occupations with highest risk of the tumour were paper and printing workers, professionals, and administrators. Exposures to various specific occupational agents that have been suggested in publications as potential risk factors were examined, but none showed an association with risk. The relative risk for occupational exposure to ionising radiation was 1.62 (95% confidence interval 0.83-3.17).

Trebling of the incidence of testicular cancer in victoria, Australia (1950-1985)

Changes in the incidence of testicular cancer in Victoria, Australia were studied from 1950 to 1985. Cases from the period 1950 to 1978 were derived from many sources (1116 cases). Emphasis was placed on diagnostic reliability; 97% of cases were confirmed histologically, and of these, 86% were reviewed at the Peter MacCallum Cancer Institute. For the years 1982 to 1985, Victorian Cancer Registry data were used. The incidence rose by a factor of 2.9 from 1.44 (95% confidence interval [CI], 1.15 to 1.73) per 100,000 in 1950 to 1954 to 4.16 (95% CI, 3.73 to 4.59) per 100,000 in 1982 to 1985. Between 1950 to 1954 and 1965 to 1969, there was a sharp rise, followed by a plateau or dip, then a further rise. Among seminomas, the rates rose in most adult age groups, whereas among nonseminomas, the rise was concentrated in younger age groups. There was a significant trend to earlier age of occurrence among nonseminomas (P = 0.0004) but not among seminomas (P = 0.89). Cohort analysis revealed a trend toward increasing rates for both seminomas and nonseminomas, and confirmed the trend toward earlier age of onset for nonseminomas. Disproportionate increases were observed for the 1915 to 1924 cohort of seminomas and the 1930 to 1939 cohort of nonseminomas. Analysis of available data from other Australian states indicated comparable rising incidence in New South Wales, Tasmania, and Western Australia.

Occupation and the occurrence of testicular cancer

To investigate what role a man's occupation may have on his risk of testicular cancer, we conducted a case-control study among noncryptorchid white males who were between 20 and 69 years of age and resided in western Washington State. Cases were men in whom a germ cell tumor of the testis was diagnosed between 1977 and 1984 (n = 323). Their occupational histories were compared to those of controls of the same age, race, and geographic area who were selected through random-digit dialing (n = 658). Administrators/managers (relative risk (RR) = 1.5), salesmen (RR = 1.5), electricians (RR = 2.8), and sailors and fishermen (RR = 3.1) were among the jobs reported more commonly by cases than controls. The risk among farmers/farm managers was also elevated (RR = 1.9), but not that among farm workers (RR = 0.6). No consistent association between any one occupation and testicular cancer has been observed across studies of this topic. The most frequent observation has been an over-representation among cases of certain types of white collar worker; this may reflect the influence of some other aspect of socioeconomic status and not occupational exposures per se.