Risk factors for testicular germ cell tumours by histological tumour type. United Kingdom Testicular Cancer Study Group

Perinatal determinants of germ-cell testicular cancer in relation to histological subtypes

We aimed to investigate the role of perinatal determinants on the risk for germ-cell testicular cancer, with respect to the aetiological heterogeneity between seminomas and non-seminomas. A case-control study of 628 case patients with testicular cancer (308 seminomas and 320 non-seminomas) and 2309 individually matched controls was nested within a cohort of boys born from 1920 to 1980 in two Swedish regions (Uppsala-Orebro Health Care Region and Stockholm). Cases were diagnosed from 1958 to 1998 and were identified through the Swedish National Cancer Registry. Perinatal information on cases and controls was collected through charts available at maternity wards. Gestational duration, categorised in three categories (<37, 37-41, >41 weeks), was negatively associated with the risk for testicular cancer (P value for linear trend=0.008). A protective effect of long gestational duration and an increased risk for high birth weight were found for seminomas. Non-seminomas were associated with short gestational duration, particularly among those with low birth order (odds ratio: 3.02, 95% confidence intervals: 1.53-5.97) and high maternal age (odds ratio: 2.33, 95% confidence intervals: 1.19-4.55). No significant differences were found in tests for heterogeneity between the two histological groups. Our data support the hypothesis that intrauterine environment affects the risk for germ-cell testicular cancer. Seminomas and non-seminomas seemed to have similar risk patterns, although they are not entirely congruent.

Occupational risks for male fertility: an analysis of patients attending a tertiary referral centre

The impact of environment and occupation on male fertility is still under debate. We investigated whether certain occupations may be over- or under-represented among men attending our infertility clinic in relation to the entire population of the area. Diagnoses and semen parameters of 2054 infertile men from the district of Münster were analysed retrospectively. The patients were categorized into 29 occupational groups. The relative size of each group was compared with that of the entire population in the district of Münster. Farmers were over-represented compared with the general population. Farmers and painters/varnishers showed a significantly higher proportion of reduced sperm counts [odds ratios (OR): 2.13 and 2.17, 95% confidence intervals: 1.18-3.88 and 1.02-4.65] and severely reduced sperm concentrations compared with the entire group of infertile men; in addition, significantly more farmers presented with a history of maldescended testes than other occupational groups (OR: 2.76 and 2.84; CI: 1.12-6.75 and 1.27-6.34). Metal workers/welders formed significantly higher proportions of patients with reduced sperm motility (OR: 5.99; CI: 1.38-26.00). The relatively poor semen parameters of the painters/varnishers could be caused by exposure to toxins. This may also apply to the farmers (fertilizers, herbicides); however, the elevated rate of maldescended testes suggests an effect of exposure during prenatal development or a genetic cause. The findings for metal workers/welders may be because of heat or toxins at the workplace. The study demonstrates that certain occupations are preferentially associated with male infertility.

Undescended testis and the risk of testicular cancer: importance of source and classification of exposure information

BACKGROUND

The strength of the association between undescended testis and testicular cancer varies considerably across studies. Here we report the effect of various classifications of self-reported history of undescended testis and different data sources on the estimates of the risk of testicular cancer from a case-control study.

METHODS

We performed a population-based case-control study including 269 testicular cancer cases and 797 controls matched on age and region. Medical history was assessed by interviews (index persons) and mailed questionnaires (mothers). We used conditional logistic regression to calculate odds ratios (OR) and kappa coefficients to assess agreement between different sources of information.

RESULTS

Odds ratios for testicular cancer ranged between 2.4 and 5.4 based on the sons' self-reports and between 1.1 and 1.9 based on the mothers' reports. The agreement between the sons and mothers on undescended, gliding or retractile testis was fair (kappa 0.53) and was good when these conditions were treated by surgery (kappa 0.89). The rating of a history of undescended testis by two urologists was fair (kappa 0.54).

CONCLUSIONS

The questionnaire design, the classifications of undescended testis and data sources have an important impact on the OR for the association of undescended testis and testicular cancer. These factors may partially explain the heterogeneity of the OR for this association in case-control studies relying on self-reports.

Trends in testicular carcinoma in England and Wales, 1971-99

OBJECTIVES

To examine incidence, mortality and survival trends in England and Wales for testicular cancer, using the recently developed national cancer and national mortality databases.

METHODS

The directly age-standardized incidence rates for testicular cancer in England and Wales were calculated for the period 1971-97 and age-standardized mortality for years 1971-99. Trends in the data were then assessed, including the influence of social deprivation on testicular cancer incidence and survival.

RESULTS

The number of newly diagnosed cases of testicular carcinoma in 1971-97 in England and Wales increased from almost 650 to 1400. The age-standardized rates were 2.9 per 100000 cases in 1971 and 5.4 per 100000 in 1997, an increase of 88% over 26 years. There was a large decrease in mortality since the mid-1970s, with an age-standardized mortality of < 0.5 per 100000 since 1985. For men with testicular carcinoma diagnosed in 1991-93, the 1-year relative survival was almost 98% and 5-year relative survival almost 95%, compared with 82% and 69%, respectively, for men diagnosed during 1971-75. There is a 'deprivation gap' for the 5-year survival of > 6% in favour of the most affluent socio-economic group, with no significant change over recent years.

CONCLUSIONS

The incidence of testicular cancer is increasing in England and Wales, consistent with the trend documented in other developed countries. The reduction in mortality has been marked since the mid-1970s, reflecting improved cancer management, in particular the introduction of platinum-based chemotherapy regimens for advanced disease. Survival rates in England and Wales are as good as in other European countries. Further developments in chemotherapy are unlikely to produce such a marked improvement in survival rates again, and minimizing the effect of social status on survival rates should be an important target of future care.

Prognostic parameters for the management of advanced testis tumours

The need for prognostic parameters in testicular germ cell tumours is sometimes questioned based on an overall cure rate of more than 80% of the patients regardless of tumour stage. However, the trend for an earlier and more accurate diagnosis amenable to curative treatment as well as the high effectiveness of standard Cisplatinum containing chemotherapy has masked the continuing need for intensifying therapy in patients with adverse risk factors. This intense treatment is often associated with worrysome morbidity and the assessment of prognostic factors, stage by stage, is warranted on which patient at risk can be identified and treated accordingly. Traditional prognostic factors, on which most classification systems are based, include large tumour volume, the presence of liver, bone or brain metastasis, grossly elevated tumour markers and an extragonadal primary site, particularly in the mediastinum. Novel prognostic factors are either (1) independent from the patient and his disease, (2) inherent on the patient's characteristics or (3) based on tumour biology. Clearly, the infrastructure and the experience of the treating uro-oncology unit (see 1) is decisive for treatment outcomes, and -at least-'difficult to treat' patients should be referred to properly resourced cancer centres. Patients with higher socio-economic status, willing to travel and well educated enough to be worried about their diseases status apparently gain access to expert centres more easily (see 2), translating into an upgrade on prognosis. Finally, biologic factors (see 3) such as beta-human chorionic gonadotrophin or MAGE epitopes in seminoma or the percentage of embryonal carcinoma components orvascular invasion mayor may not inversely influence the prognosis and need further assessment in prospective trials. However, the search for even better (molecular) biologic factors is speeding up because more complex treatment decisions such as in advanced testicular cancers rely on a more precise determination of prognosis, enabling a more tailored selection of individualized therapeutic options.

Current opinion in germ cell cancer 2000

Despite its relative rarity compared with the common adult cancers, scientific and clinical interest in germ cell cancer is increasing. From the point of view of epidemiology, the controversy about the relative importance of intrauterine versus postpubertal risk factors has continued. Evidence to support the importance of intrauterine factors comes from reports from Norway, Canada, and the US, confirming the Danish observation that the rising incidence of germ cell cancer is linked to a birth cohort effect; evidence in support of the importance of postpubertal risk comes from three case/control studies demonstrating increased risk linked to postpubertal exposures such as pesticides, plastics, electromagnetic radiation, trauma, and infections. There has been increasing interest in human endogenous retrovirus K10 as a possible factor explaining genetic susceptibility and providing a linkage between the two groups of risk factors. In cytogenetics, progress was reported in identifying the deletion point of the suspected tumor suppressor gene responsible for the i12p marker chromosome abnormality and development of FISH probes for diagnostic purposes. In molecular biology, the importance of DNA repair deficiency in normal germ cells as a factor in the exquisite chemosensitivity of germ cell cancer has been high-lighted by a report demonstrating a low level of the xeroderma pigmentosa group A (XPA) protein and induction of resistance in vitro by adding XPA. In the clinic, progress in positron emission tomography scanning and laparoscopic lymph node staging are leading to changes in outlook on management of stage 1 cases and patients with small residual masses postchemotherapy. Salvage chemotherapy regimens integrating dose dense and vertical dose intensification strategies reported 60% progression-free survival. New drugs such as gemcitabine demonstrated continued therapeutic potential for chemotherapy in these tumors. A report demonstrating the inadequacies of hormone replacement after bilateral orchidectomy and a report of the first child born after testis-conserving therapy highlight the need for more attention to testis conservation as a quality of life issue. With the cure rates so high, the need for central referral is once again debated both for stage 1 and metastatic disease. With new ways of defining poor risk stage 1 patients and reports on impact of experience highlighting the worse outcome of patients treated in centers treating small numbers, views on this issue remain clearcut.