Risk of cancer in migrants and their descendants in Israel: II. Carcinomas and germ-cell tumours

Residence near industrial complex and cancer incidence: A registry-based cohort of 1,022,637 participants with a follow-up of 21 years, Israel

BACKGROUND

Industrial complex (IC) residence is associated with higher cancer incidence in adults and children. However, the effect on young adults and the residence duration are not well described. Since the beginning of the 20th century, the Haifa bay area (HBA) has a major IC area with petrochemical industry complex and many other industries. The objectives of the current study were to estimate the association between IC residence and cancer incidence and to evaluate the effect of the residence duration.

METHODS

This study is a registry-based cohort (N = 1,022,637) with a follow-up of 21 years. Cox regression models were used to evaluate the associations (hazards ratios (HR) and its 95% confidence intervals (CIs)) between HBA residence and incidence of all cancer sites (n = 62,049) and for site-specific cancer types including: lung cancer (n = 5398), bladder cancer (n = 3790), breast cancer (n = 11,310), prostate cancer (n = 6389) skin cancer (n = 4651), pancreatic cancer (n = 2144) and colorectal cancer (n = 8675). We evaluated the effect of the duration of exposure as categories of 7 years for those with 15 years of follow-up.

RESULTS

IC residence was associated with higher risk for all cancer sites (HR:1.09, 95% CI: 1.06-1.12), for site-specific cancer incidence including: lung cancer (HR:1.14, 95% CI: 1.04-1.23), bladder cancer (HR:1.11, 95% CI: 1.01-1.23), breast cancer (HR:1.04, 95% CI: 0.98-1.10), prostate cancer (HR:1.07, 95% CI: 0.99-1.16), skin cancer (HR:1.22, 95% CI: 1.12-1.33) and colorectal cancer (HR:1.10, 95%CI: 1.03-1.17). Similar risk was also observed among young adults (HR: 1.10, 95% CI: 1.00-1.20). In the analyses for the duration of exposure, IC residence was associated with higher risk for all cancer site for the longest residence duration (15-21 years: HR: 1.08, 95% CI: 1.04-1.13).

CONCLUSIONS

Harmful associations were found between IC residence and incidence of all cancer sites and site-specific cancers types. Our findings add to the limited evidence of associations between IC residence and cancer in young adults.

Mortality Advantage Reversed: The Causes of Death Driving All-Cause Mortality Differentials Between Immigrants, the Descendants of Immigrants and Ancestral Natives in Sweden, 1997-2016

A small but growing body of studies have documented the alarming mortality situation of adult descendants of migrants in a number of European countries. Nearly all of them have focused on all-cause mortality to reveal these important health inequalities. This paper takes advantage of the Swedish population registers to study all-cause and cause-specific mortality among men and women aged 15-44 in Sweden from 1997 to 2016 to a level of granularity unparalleled elsewhere. It adopts a multi-generation, multi-origin and multi-cause-of-death approach. Using extended, competing-risks survival models, it aims to show (1) how the all-cause mortality of immigrants arriving as adults (the G1), immigrants arriving as children (the G1.5) and children of immigrants born in Sweden to at least one immigrant parent (the G2) differs versus ancestral Swedes and (2) what causes-of-deaths drive these differentials. For all-cause mortality, most G1 (not Finns or Sub-Saharan Africans) have a mortality advantage. This contrasts with a near systematic reversal in the mortality of the G1.5 and G2 (notably among men), which is driven by excess accident and injury, suicide, substance use and other external cause mortality. Given that external causes-of-death are preventable and avoidable, the findings raise questions about integration processes, the levels of inequality immigrant populations are exposed to in Sweden and ultimately, whether the legacy of immigration has been positive. Strengths of the study include the use of quality data and advanced methods, the granularity of the estimates, and the provision of evidence that highlights the precarious mortality situation of the seldom-studied G1.5.

Proximity to endocrine-disrupting pesticides and risk of testicular germ cell tumors (TGCT) among adolescents: A population-based case-control study in California

BACKGROUND

The incidence of testicular germ cell tumors (TGCT) is increasing steadily in the United States, particularly among Latinos. TGCT is thought to be initiated in utero and exposure to endocrine-disrupting chemicals, suspected contributors to TGCT pathogenesis, during this critical developmental period may contribute to the rise.

OBJECTIVES

To assess the relationship between fetal exposure to agricultural endocrine-disrupting pesticides (EDPs) and TGCT risk among adolescents in a diverse population in California.

METHODS

We conducted a registry-based case-control study of TGCT. Cases, diagnosed between 1997 and 2011, were 15-19 years of age (n = 381). Controls were matched on birth year and race/ethnicity (n = 762). Quantities (kilograms) of 33 pesticides applied within 3 km and 1 km radii of each individual's address before birth were estimated using the Pesticide Use Reporting database. Odds ratios (OR), 95% confidence intervals (CI), and population attributable risk (PAR) were calculated for each EDP (using log-2 transformed values). Risk models considered race/ethnicity, birth year, and neighborhood socioeconomic status.

RESULTS

A doubling of nearby acephate applications (3 km and 1 km radii) and malathion applications (1 km radius) was associated with increased risks of TGCT among Latinos only (OR = 1.09; 95% CI:1.01-1.17; 1.30; 95% CI:1.08-1.57, and 1.19; 95% CI:1.01-1.39, respectively), whereas application of carbaryl within a 3 km radius increased TGCT risk in non-Latinos only (OR = 1.14, 95% CI:1.01-1.28). We estimate that acephate was associated with approximately 10% of the TGCT PAR, malathion with 3% and carbaryl with 1%.

CONCLUSIONS

TGCT among adolescents in California was associated with prenatal residential proximity to acephate and malathion among Latinos, and with carbaryl among non-Latinos. These results suggest that the rise in TGCT risk among Latinos may be associated with exposure to these pesticides.

The Evolving Epidemiology of Nasopharyngeal Carcinoma

BACKGROUND

The epidemiology of nasopharyngeal carcinoma (NPC) has long been a source of fascination due to the malignancy's striking geographic distribution, the involvement of the oncogenic Epstein-Barr virus (EBV), the unique association with intake of Chinese-style salt-preserved fish, and etiologic heterogeneity by histologic subtype.

METHODS

This review summarizes the current epidemiologic literature on NPC, highlighting recent results from our population-based case-control study in southern China.

RESULTS

Findings from our case-control study provide new insight into the epidemiology of NPC, including a diminished role of Chinese-style salt-preserved fish, a profound impact of EBV genetic sequence variation, modest positive associations with passive smoking and household air pollution, and possible effects of oral health and the oral microbiome. Recent findings from other studies include a protective association with infectious mononucleosis, suggesting a causal role of early EBV infection; familial risk conferred by shared genetic variation in the host antibody-mediated immune response to EBV infection; and an unclear association with occupational exposure to formaldehyde.

CONCLUSIONS

To shed further light on the interplay of environmental, genetic, and viral causes of NPC, large pooled studies must accumulate sufficient cases with detailed exposure data.

IMPACT

New epidemiologic findings have reshaped the causal model for NPC.

Increasing Incidence of Testicular Germ Cell Tumors among Racial/Ethnic Minorities in the United States

BACKGROUND

The incidence of testicular germ cell tumors (TGCT) has been rising in the United States and is notably higher among white men. Previously, our group reported that rates were rising among Hispanic men in certain areas. This study sought to determine whether the patterns noted in our prior publication remained evident in more recent years and to determine whether any new patterns have emerged.

METHODS

Data from 51 U.S. cancer registries were examined. Racial/ethnic-specific incidence rates per 100,000 man-years were calculated overall and by census region. Annual percent changes (APC) were estimated, and joinpoint models were fit. Differences in regional incidence were examined using the Wald test.

RESULTS

During the time period 2001 to 2016, 126,575 TGCTs were recorded. TGCT incidence was highest among non-Hispanic whites (NHW; 6.63/100,000), followed by Hispanics (4.20), American Indian/Alaska Natives (AI/AN; 3.27), Asian/Pacific Islanders (A/PI; 1.72), and non-Hispanic blacks (NHB; 1.27). TGCT incidence increased significantly among all men; the greatest increase was experienced by A/PIs (APC: 2.47), followed in order by Hispanics (2.10), AI/ANs (1.71), NHBs (1.28), and NHWs (0.41). Significant differences in rates by region were seen for all men except NHBs, with the highest rates among Hispanics (5.38/100,000), AI/ANs (4.47), and A/PIs (2.37) found in the West, and among NHWs (7.60) and NHBs (1.51) found in the Northeast.

CONCLUSIONS

Although TGCT incidence remained highest among NHWs between 2001 and 2016, the greatest increase was experienced by A/PI men.

IMPACT

Rising rates of TGCTs among men of all racial/ethnic backgrounds in the United States suggest that future attention is warranted.

Update on epidemiologic considerations and treatment trends in testicular cancer

PURPOSE OF REVIEW

We aim to give an overview of the epidemiology and treatment trends of testicular germ cell tumors (TGCTs), with an emphasis on recent trends.

RECENT FINDINGS

The incidence of TGCT appears to be increasing, particularly in developed countries, although the reasons are not well understood. There is evidence of racial differences in predisposition to TGCT, with white men having highest risk and men of African or Asian descent having lower risk. In the United States, the incidence of TGCT among Hispanics appears to be rising most quickly. A recent genomic analysis indicates there is no highly penetrant major TGCT susceptibility gene. Incorporation of multidisciplinary care has led to excellent long-term cure rates; however, access to care and insurance remains barriers in young men. Recent treatment trends have centered on maximizing oncologic outcomes while minimizing long-term morbidity.

SUMMARY

Emerging population-level data provide critical insight into the evolving demographics of TGCT, which may allow for elucidation of biologic and environmental determinants of TGCT. Further, identification of socioeconomic barriers to excellent clinical outcomes will allow for targeted interventions to patients with unique demographic and socioeconomic considerations. Treatment trend analyses suggest that the field is moving toward minimizing treatment-related morbidity.

Nasopharyngeal carcinoma: A review of current updates

Nasopharyngeal carcinoma (NPC) is a rare malignancy worldwide, but it is endemic in a few areas including Southern China, Southeast Asia, North Africa and the Arctic. The underlying mechanisms behind this remarkable geographic distribution remain unclear. Although Epstein-Barr virus (EBV) infection has been suggested as a necessary cause of undifferentiated NPC, EBV itself is not sufficient to cause this malignancy. Other co-factors, such as environmental risk factors, and/or genetic susceptibility, may interact with EBV to play a role in the carcinogenesis of NPC. Survival rates differ significantly between NPC patients in early stages and late stages. Due to the close associations between EBV infection and NPC risk, EBV-related biomarkers have been used for early detection and screening for NPC in a few high-incidence areas. In the present review article the latest updates are discussed.

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.

Biological aspects of human migration and mobility

This paper reviews how migration, both geographical and social, impacts on variation in some human biological traits. Migration and mobility are considered in relation to anthropometric traits and indices, psychometric traits, health, disease and nutrition, temperature regulation and metabolism, mental health and gene flow. It is well known that migration is important in disease transmission but, as this paper demonstrates, migration can have both positive and negative impacts on both donor and recipient populations for a wide range of human traits.

Reproductive risk factors associated with breast cancer in women in Bangui: a case-control study

Background

Breast cancer (breast Ca) is recognised as a major public health problem in the world. Data on reproductive factors associated with breast Ca in the Central African Republic (CAR) is very limited. This study aimed to identify reproductive variables as risk factors for breast Ca in CAR women.

Methods

A case–control study was conducted among 174 cases of breast Ca confirmed at the Pathology Unit of the National Laboratory in Bangui between 2003 and 2015 and 348 age-matched controls. Data collection tools included a questionnaire, interviews and a review of medical records of patients. Data were analysed using SPSS software version 20. Odd ratios and 95% confidence intervals (CI) for the likelihood of developing breast Ca were obtained using unconditional logistic regression.

Results

In total, 522 women with a mean age of 45.8 (SD = 13.4) years were enrolled. Women with breast Ca were more likely to have attained little or no education (AOR = 11.23, CI: 4.65–27.14 and AOR = 2.40, CI: 1.15–4.99), to be married (AOR = 2.09, CI: 1.18–3.71), to have had an abortion (AOR = 5.41, CI: 3.47–8.44), and to be nulliparous (AOR = 1.98, CI: 1.12–3.49). Decreased odds of breast Ca were associated with being employed (AOR = 0.32, CI: 0.19–0.56), living in urban areas (AOR = 0.16, CI: 0.07–0.37), late menarche (AOR = 0.18, CI: 0.07–0.44), regular menstrual cycles (AOR = 0.44, CI: 0.23–0.81), term pregnancy (AOR = 0.26, CI: 0.13–0.50) and hormonal contraceptive use (AOR = 0.62, CI: 0.41–0.93).

Conclusion

Breast Ca risk factors in CAR did not appear to be significantly different from that observed in other populations. This study highlighted the risk factors of breast Ca in women living in Bangui to inform appropriate control measures.

Germ Cell Testicular Cancer Incidence, Latitude and Sunlight Associations in the United States and Australia

International patterns suggest germ cell testicular cancer (GCTC) incidence may be lower in lower latitudes. To investigate this possibility, we examined GCTC incidence by latitude (population centroid in 2000) for men ≥15 years within two reasonably homogeneous countries, the United States and Australia. In the United States, we examined age-adjusted incidence/latitude trends using data from states (2001-2010) and local-area registries (1980-2011). In Australia, we evaluated incidence/latitude trends in 61 Statistical Divisions (2000-2009). In U.S. White men (68 566 cases), state incidences increased by latitude, rising 5.74% (4.45-7.05%) per 5°North latitude increment. Similar trends were found for seminoma and nonseminoma subtypes (P < 0.001). In U.S. Black men (2256 cases), the association was also seen (4.9%; 0.2-9.7%). In local U.S. data, similar increases in incidence with latitude were present in each of the last three decades. In Australia (6042 cases), the incidence increased by 4.43% (95% CI: 1.54-7.39%) per 5°South, and trends for subtypes were similar. Thus, we found that incidence of GCTC in both White and Black men increased significantly with distance from the equator, approximately 1% per degree within the range of latitudes studied.

Incidence of testicular germ cell tumors among US men by census region

BACKGROUND

The incidence of testicular germ cell tumors (TGCTs) in the United States is notably higher among white men versus other men. Previously, however, it was reported that rates were rising among Hispanics in certain areas. To determine whether this finding was evident in a wider area of the United States, data from 39 US cancer registries were examined.

METHODS

Racial/ethnic-specific incidence rates per 100,000 man-years were calculated overall and by census region for the period of 1998-2011. Annual percentage changes (APCs) were estimated, and joinpoint models were fit. Differences in incidence by region were examined with the Wald test.

RESULTS

From 1998 to 2011, 88,993 TGCTs were recorded. The TGCT incidence was highest among non-Hispanic whites (6.57 per 100,000), who were followed by Hispanics (3.88), American Indians/Alaska Natives (2.88), Asians/Pacific Islanders (A/PIs; 1.60), and non-Hispanic blacks (1.20). The incidence significantly increased among Hispanics (APC, 2.31; P < .0001), with rates rising in all regions except the South. Rates rose slightly among non-Hispanic whites (APC, 0.51; P = .0076). Significant differences in rates by region were seen for Hispanics (P = .0001), non-Hispanic whites (P < .0001), and A/PIs (P < .0001), with the highest rates among Hispanics in the West and with the highest rates among non-Hispanic whites and A/PIs in the Northeast.

CONCLUSIONS

Although the incidence of TGCTs remained highest among non-Hispanic whites between 1998 and 2011, the greatest increase was experienced by Hispanics. Rising rates of TGCTs among Hispanics in the United States suggest that future attention is warranted. Reasons for the increase may include variability in birthplace, changing exposures, genetic susceptibility, and the length of US residence.

Cancer in immigrants as a pointer to the causes of cancer

The early cancer studies on immigrants, which started to appear some 50 years ago, showed that the incidence in cancers changes to the level of the new host country in one or two generations. These findings were fundamental to the understanding of the environmental etiology of human cancer. Many immigrant groups originate from countries with no cancer registration, and, hence, the immigrant studies may provide estimates on the indigenous cancer rates. The Swedish Family-Cancer Database has been an important source of data for immigrant studies on various diseases. The Database covers the Swedish population of the past 100 years, and it records the country of birth for each subject. A total of 1.79 million individuals were foreign born, Finns and other Scandinavians being the largest immigrant groups. Over the course of years, some 30 publications have appeared relating to cancer in immigrants. In the present article, we will review more recent immigrant studies, mainly among Swedish immigrants, on all cancers and emphasize the differences between ethnic groups. In the second part, we discuss the problem of reliable registration of cancer and compare cancer incidence among non-European immigrants with cancer incidence in countries of origin, as these have now active cancer registries. We discuss the experiences in cancer registration in Morocco and Egypt. We show the usefulness and limitations in predicting cancer incidence in the countries of origin.

Recent trends in the incidence of testicular germ cell tumors in the United States

Testicular germ cell tumors (TGCT), which comprise 98% of all testicular malignancies, are the most commonly occurring cancers among men between the ages of 15 and 44 years in the United States (US). A prior report from our group found that while TGCT incidence among all US men increased between 1973 and 2003, the rate of increase among black men was more pronounced starting in 1989-1993 than was the rate of increase among other men. In addition, TGCT incidence increased among Hispanic white men between 1992 and 2003. To determine whether these patterns have continued, in the current study, we examined temporal trends in incidence through 2011. Between 1992 and 2011, 21 271 TGCTs (12 419 seminomas; 8715 non-seminomas; 137 spermatocytic seminomas) were diagnosed among residents of the Surveillance, Epidemiology, and End Results 13 registry areas. The incidence of TGCT was highest among non-Hispanic white men (6.97 per 100 000 man-years) followed by American Indian/Alaska Native (AI/AN; 4.66), Hispanic white (4.11), Asian/Pacific Islander (A/PI; 1.95), and black (1.20) men. Non-Hispanic white men were more likely to present with smaller tumors (3.5 cm) and localized disease (72.6%) than were men of other races/ethnicities. Between 1992 and 2011, TGCT incidence increased significantly among Hispanic white [annual percent change (APC) = 2.94, p < 0.0001], black (APC = 1.67, p = 0.03), non-Hispanic white (APC = 1.23, p < 0.0001), and A/PI (APC = 1.04, p = 0.05) men. Incidence rates also increased, although not significantly, among AI/AN men (APC = 2.96, p = 0.06). The increases were greater for non-seminoma than seminoma. In summary, while non-Hispanic white men in the US continue to have the highest incidence of TGCT, they present at more favorable stages of disease and with smaller tumors than do other men. The increasing rates among non-white men, in conjunction with the larger proportion of non-localized stage disease, suggest an area where future research is warranted.

Country of origin, age at migration and risk of cutaneous melanoma: a migrant cohort study of 1,100,000 Israeli men

Cutaneous melanoma (CM) is a common cancer with increasing incidence in many parts of the world where light-skinned populations live. We conducted a large-scale nationally representative migrant cohort study to assess country of origin and age at migration as predictors of CM, controlling for possible confounders. Data on 1,086,569 Israeli Jewish males, who underwent a general health examination before compulsory military service at ages 16-19 between the years 1967-2005, were linked to Israel National Cancer Registry to obtain incident CM up to 2006. Cox proportional hazards was used to model time to event. Overall, 1562 incident cases were detected during 19.3 million person-years of follow-up. Origin was a strong independent predictor of CM. Incidence was higher for European (hazard ratio [HR] = 4.08, 95% confidence interval [CI]: 3.55-4.67) and Israeli origin (HR = 2.92, 95% CI: 2.25-3.79) compared to N. African/Asian origin, adjusted for year of birth, years of education, residential socio-economic position, rural residence and body surface area (or height). Among those of European origin, the adjusted risk was significantly lower for those who immigrated after the age of 10 years (HR = 0.58, 95% CI: 0.45-0.73) but not for younger ages (HR = 1.02, 95% CI 0.84-1.23) compared to Israeli born. The high rates of CM among men of European origin and the almost twofold lower risk among those immigrating after age 10 provide solid support for the deleterious role of childhood sun exposure as a risk factor for melanoma. These findings will serve in directing public health and research efforts.

Brain metastasis of nasopharyngeal carcinoma: a case report and literature review

Central nervous system metastases from nasopharyngeal carcinoma (NPC) are uncommon. The patient presented was diagnosed with aggressive advanced NPC resistant to treatment and complicated by a solitary brain metastasis. A PubMed database search was conducted to review the existing literature regarding brain metastases of NPC, using the search terms “nasopharyngeal neoplasia,” “nasopharyngeal carcinoma,” “nasopharynx,” “radiotherapy,” “central nervous system,” and “brain” in section of “Title/Abstract.” The articles were first evaluated by title and then by abstract, and thereafter appropriate manuscripts were evaluated by full text. References of the published papers were also reviewed.

Can global variation of nasopharynx cancer be retrieved from the combined analyses of IARC Cancer Information (CIN) databases?

BACKGROUND

The international nasopharynx cancer (NPC) burdens are masked due to the lack of integrated studies that examine epidemiological data based on up-to-date international disease databases such as the Cancer Information (CIN) databases provided by the International Agency for Research on Cancer (IARC).

METHODS

By analyzing the most recently updated NPC epidemiological data available from IARC, we tried to retrieve the worldwide NPC burden and patterns from combined analysis with GLOBOCAN2008 and the Cancer Incidence in Five Continents (CI5) databases. We provide age-standardized rates (ASR) for NPC mortality in 20 highest cancer registries from GLOBOCAN2008 and the World Health Organization (WHO) mortality databases, respectively. However, NPC incidence data can not be retrieved since it is not individually listed in CI5 database. The trend of NPC mortality was investigated with Joinpoint analysis in the selected countries/regions with high ASR.

RESULTS

GLOBOCAN 2008 revealed that the highest NPC incidence rates in 2008 were in registries from South-Eastern Asia, Micronesia and Southern Africa with Malaysia, Indonesia and Singapore ranking the top 3. WHO mortality database analysis revealed that China Hong Kong, Singapore and Malta ranks the top 3 regions with the highest 5-year mortality rates.

CONCLUSIONS

NPC mortality rate is about 2-3 times higher in male than that in female, and shows decrease tendency in those selected countries/regions during the analyzed periods. However, the integrated analyses of the current IARC CIN databases may not be suitable to retrieve epidemiological data of NPC. Much effort is required to improve the local cancer entry and regional death-reporting systems so as to aid similar studies.

[Undifferentiated nasopharyngeal carcinoma in adolescent and children]

Malignant tumours with nasopharyngeal primary location are relatively rare in children. One of the most frequent paediatric neoplasms in this region is the undifferentiated nasopharyngeal carcinoma tumour (UCNT). These tumours are usually revealed by nasal obstruction, headache or cervical nodal involvement. The nasopharyngeal mass can be discovered during an ear-nose and throat examination and confirmed after medical imaging investigation. Diagnostic is obtained by nasopharyngeal mass or cervical nodal biopsy. This tumor has a high chemo and radio-sensibility in children. Irradiation of the cavum and the nodes areas remains as the reference treatment of this disease. Most paediatric protocols add chemotherapy to radiotherapy. The value of concomitant or adjuvant chemotherapy is still debated in paediatric population. It was shown that the T and N staging at diagnosis determined by the classification TNM is a major prognostic factor. Due to the importance of the loco-regional sequelae after irradiation and the satisfactory global prognosis, the actual trend is a decrease in the total dose of irradiation delivered, particularly for patient with a good response to first chemotherapy. This article sheds light on the particularities of UCNT in paediatric patients.

Red and processed meat consumption and risk of ovarian cancer: a dose-response meta-analysis of prospective studies

Background:

During the last decade, the epidemiological evidence on consumption of meat and risk of ovarian cancer has accumulated.

Methods:

We assessed the relationship between red and processed meat consumption and risk of ovarian cancer with a dose-response meta-analysis. Relevant prospective cohort studies were identified by searching the PubMed and EMBASE databases through 21 January 2011, and by reviewing the reference lists of retrieved articles. Study-specific relative risk (RR) estimates were combined using a random-effects model.

Results:

Eight cohort studies were included in the meta-analysis. The summary RR for an intake increment of 100 g per week was 1.02 (95% confidence interval (CI), 0.99–1.04) for red meat and 1.05 (95% CI, 0.98–1.14) for processed meat. For an intake increment of four servings per week, the summary RR of ovarian cancer was 1.07 (95% CI, 0.97–1.19) for red meat (100 g per serving) and 1.07 (95% CI, 0.97–1.17) for processed meat (30 g per serving).

Conclusion:

Results from this dose-response meta-analysis suggest that red and processed meat consumption is not associated with risk of ovarian cancer. Although a lower consumption of red and processed meat may offer protection against other types of cancer, other interventions are needed to reduce the risk of ovarian cancer.

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.

What has happened to human fertility?

Semen quality appears to have declined in recent decades in some populations, e.g. north-western Europe. At the same time, couple fertility may have increased. Hypotheses are suggested for this apparent inconsistency. Alongside the deterioration of spermatogenesis there is clear evidence of an increase in other related problems, notably testicular cancer. The sharply rising trend in this condition started a century ago--decades earlier than sometimes thought. This and other evidence clearly indicates an environmental origin, but there is also a definite genetic component. The relationship of genetics and environment is discussed in the context of the puzzle that infertility is inherited, which appears to be impossible from an evolutionary standpoint. Poor semen quality is related not only to testicular cancer but also to zygote development, in which cancer-like disruption of the genetic apparatus is observed, with serious implications for offspring health. This needs to be seen in the context that human reproduction is prone to a higher degree of impairment than that of other mammalian species, in relation to spermatogenesis, couple fertility, early pregnancy loss and embryonic aneuploidy; female- and male-mediated pathways are both implicated. It is unclear whether such human specificity originated on an evolutionary/genetic or a historico-social timescale, which is important in relation to pathogenesis. The evidence clearly indicates that the currently most popular explanation for male reproductive system impairment, the endocrine disruption hypothesis, cannot explain the main features of the descriptive epidemiology. An alternative pathogenesis is outlined, and some possible exposures considered that could be responsible.

The human leukocyte antigen class I genes in nasopharyngeal carcinoma risk

Nasopharyngeal carcinoma (NPC) is a virally associated cancer which is highly prevalent in Southeast Asia and North Africa. Several linkage analysis studies suggested the association of susceptibility HLA (Human Leukocyte Antigen) alleles and haplotypes with NPC development. The HLA system is very polymorphic and according to the ethnic group studied, it has been found to have the capacity to confer susceptibility or resistance to NPC. Our aim was to review the most important described genetic associations of HLA class I in NPC and to comment on the inconsistent associations found in the different NPC incidence areas. We believe that the mechanisms of these associations may involve HLA genes through the differential capacity of each allele to present antigens. However, because HLA genes contain various linked candidate genes, HLA-NPC associations should be carefully interpreted.

Genes, chromosomes and the development of testicular germ cell tumors of adolescents and adults

Testicular germ cell tumors (TGCTs) of adults and adolescents are thought to be derived from primordial germ cells or gonocytes. TGCTs develop postpuberty from precursor lesions known as intratubular germ cell neoplasia undifferentiated. The tumors can be divided into two groups based on their histology and clinical behavior; seminomas resemble primordial germ cells or gonocytes and nonseminomas resemble embryonic or extraembryonic tissues at various stages of differentiation. The most undifferentiated form of nonseminoma, embryonal carcinoma, resembles embryonic stem cells in terms of morphology and expression profiling, both mRNAs and microRNAs. Evidence supports both environmental factors and genetic predisposition underlying the development of TGCTs. Various models of development have been proposed and are discussed. In TGCTs, gain of material from the short arm of chromosome 12 is invariable: genes from this region include the proto-oncogene KRAS, which has activating mutations in approximately 10% of tumors or is frequently overexpressed. A number of different approaches to increase the understanding of the development and progression of TGCTs have highlighted the involvement of KIT, RAS/RAF/MAPK, STAT, and PI3K/AKT signaling. We review the role of these signaling pathways in this process and the potential influence of environmental factors in the development of TGCTs.

Breast Cancer among Immigrants: A Systematic Review and New Research Directions

This paper highlights the relationship between migration and female breast cancer. A comprehensive review aimed at identifying risk and protective factors that cut across races and ethnicities was performed. A total of 79 studies (1971-2005) from 16 countries were reviewed. The findings are consistent with existing knowledge about the importance of potentially modifiable environmental and behavioral determinants of risk, acting both pre- and post-migration. While the acculturation-based risk transition model is strong, it is not always supported. As a new direction for migrant studies, we extrapolate the review findings to the experience of Eastern European (EE) immigrants. Health data on this population, typically characterized by low health motivation and passive receipt of preventive efforts, are largely unavailable. Based on relevant theory, empirical and qualitative studies, two breast cancer prevention models for the EE immigrant population are proposed and the need for future research using ethnically disaggregated data is discussed.

Cancer risk in first generation migrants in North-Holland/Flevoland, The Netherlands, 1995–2004

As migrant studies can offer important information with regard to cancer aetiology, we estimated the cancer risk in first generation migrants using data of the Amsterdam Cancer Registry. The risk among western migrants was almost equal to the risk of the native population. Migrants from former Dutch colonies had a low cancer risk (standardised incidence ratios 0.69-0.81), while the lowest risks were observed for Turkey (0.66), Morocco (0.53) and sub-Sahara Africa (0.59). High risks in migrants from non-western countries were observed for cancer of the nasopharynx (China 51, Morocco 22), liver (China 13), gallbladder, cervix and thyroid, as well as for Kaposi's sarcoma, Hodgkin's lymphoma and mature T/NK-cell lymphoma. Cancer risk for breast, colorectum, lung, prostate, skin and testis was generally low. Although cancers related to infectious disease were relatively common among migrants from non-western countries, the low risks for mainly lifestyle related cancers resulted in a low overall risk.

The enigmatic epidemiology of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has a unique and complex etiology that is not completely understood. Although NPC is rare in most populations, it is a leading form of cancer in a few well-defined populations, including natives of southern China, Southeast Asia, the Arctic, and the Middle East/North Africa. The distinctive racial/ethnic and geographic distribution of NPC worldwide suggests that both environmental factors and genetic traits contribute to its development. This review aims to summarize the current knowledge regarding the epidemiology of NPC and to propose new avenues of research that could help illuminate the causes and ultimately the prevention of this remarkable disease. Well-established risk factors for NPC include elevated antibody titers against the Epstein-Barr virus, consumption of salt-preserved fish, a family history of NPC, and certain human leukocyte antigen class I genotypes. Consumption of other preserved foods, tobacco smoking, and a history of chronic respiratory tract conditions may be associated with elevated NPC risk, whereas consumption of fresh fruits and vegetables and other human leukocyte antigen genotypes may be associated with decreased risk. Evidence for a causal role of various inhalants, herbal medicines, and occupational exposures is inconsistent. Other than dietary modification, no concrete preventive measures for NPC exist. Given the unresolved gaps in understanding of NPC, there is a clear need for large-scale, population-based molecular epidemiologic studies to elucidate how environmental, viral, and genetic factors interact in both the development and the prevention of this disease.

Dietary intake changes and their association with ovarian cancer risk

There are reasons to suspect that dietary changes through adult life may modify risk for some cancers. We examined the association of recent and past dietary habits and changes in dietary intake over time with ovarian cancer risk. Long-term nutritional assessment was performed retrospectively in 631 incident cases of invasive epithelial ovarian cancer and in 1174 matched controls (matched by age +/- 2 y, country of origin, and period of immigration) as part of a nationwide case-control study of ovarian cancer conducted between the years of 1994 and 1996 in Israel. Using a 2-step quantified Food Frequency Questionnaire, participants were first asked about their consumption of food items 1 y prior to the interview, and then whether their consumption had changed over time. The time of the change and consumption level before the change were recorded, allowing reconstruction of daily intakes for several time points. The reported mean percentage of animal fat intake decreased by 1.3% in cases but by 1.9% in controls (P for difference = 0.003). Conditional multivariate logistic regression was used to estimate odds ratios adjusted for total energy, parity, and oral contraceptive use. Substituting nonanimal fat in preference to animal fat over a relatively short term (between 2 and 7 y prior to interview) decreased the risk of ovarian cancer [OR = 0.65/100 kcal (418.4 kJ), 95% CI = 0.50 - 0.85]. Our results suggest that substitution of nonanimal for animal fat during adult life might reduce the risk of ovarian cancer, but this requires confirmation in prospective studies.

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.

Novel germline mutations in breast cancer susceptibility genes BRCA1, BRCA2 and p53 gene in breast cancer patients from India

Mutations in breast cancer susceptibility genes, BRCA1 and BRCA2 account for more than 80% of hereditary breast and ovarian cancers. p53 tumor suppressor gene that controls cellular growth and differentiation is also known to be mutated in more than 50% of human cancers including breast cancer. We have carried out a study on BRCA1 and BRCA2 along with p53 gene mutations in both sporadic as well as familial breast cancer patients from India where breast cancer is fast emerging as a major cancer among premenopausal urban women. We examined 124 untreated primary breast cancer patients comprising 100 sporadic and 24 familial cases including 56 age-matched healthy controls for the presence of BRCA1, BRCA2 and the p53 gene mutations using PCR-SSCP and direct nucleotide sequencing. Certain frequently mutated exons such as 2, 5, 11, 13 and 20 of BRCA1, exons 2, 9, 11 (for 6174delT), 18 and 20 of BRCA2 and 4-9 exons of p53 gene were analyzed in sporadic breast cancer while all 22 coding exons of BRCA1 including its flanking intronic regions along with above mentioned exons of BRCA2 and p53 gene were analyzed in familial breast cancer patients. We identified six patients (25%) with BRCA1 mutation of which three were found to be of novel type one in exon 16 (4956insG) and two in exon 7 (Lys110Thr) (Ser114Pro) out of 24 familial breast cancer patients studied from two different geographic regions/populations of India. Two sisters from a single family (12.5%) out of eight families from Goa with Portuguese colonial origin showed presence of founder Ashkenazi Jewish BRCA1 mutation (185delAG) along with (IVS7 561-34T>C; IVS18 5271 + 66G > A). While from New Delhi, four (25%) of 16 breast cancer families showed BRCA1 mutations; a frame shift protein truncating (4956insG), a transition nonsense (Gln1395Stop) and two amino acid substitutions (Lys110Thr) and (Ser114Pro). Only one (4%) p53 mutation (Val97Ile) in its exon 4 along with BRCA1 mutation (4956insG) could be detected. No major sequence variation in BRCA2 gene was observed except for G203A at 5' UTR of exon 2, a common population polymorphism in two Goan patients who also showed silent nucleotide change for amino acid serine at codon 1436 of BRCA1 gene. None of the 100 sporadic breast cancer patients revealed any protein truncating or deleterious BRCA1 or BRCA2 gene mutation. Interestingly, three (3%) p53 mutations in its exon 5 were detected in sporadic breast cancer patients. Although three novel BRCA1 mutations including a founder Ashkenazi Jewish BRCA1 mutation were recorded in Indian women with familial breast cancer, the overall prevalence of BRCA gene mutations in Indian women with a family history of breast cancer appears to be low.

Genetic predisposition to testicular germ-cell tumours

Testicular germ-cell tumours (TGCT) are the most common neoplasm in young men. Various studies have suggested the existence of an inherited predisposition to development of these tumours. Genome-wide screens subsequently provided evidence of a TGCT susceptibility gene on chromosome Xq27 (TGCT1) that might also predispose to cryptorchism. However, this putative gene has yet to be identified, and other TGCT susceptibility genes probably exist. Completion of the human gene map and advances in genetic research will facilitate further investigation of genetic predisposition to TGCT. Insight into inheritance of TGCT might lead to the identification of individuals at increased risk of developing the disorder, increase our understanding of the mutation pathways that lead to sporadic cases, and contribute to improvement in diagnosis and treatment. Clinicians should record the family history of cancer and urogenital differentiation defects in patients with TGCT.

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.

High Incidence of Nasopharyngeal Carcinoma in Native People of Sarawak, Borneo Island

Nasopharyngeal cancer (NPC) is generally a rare malignancy with a few well-known exceptions, notably South-East China. In this article, we describe evidence of a high risk of NPC in the population of Sarawak State, Malaysia, and particularly in one native ethnic group. Sarawak State is one of the two provinces of Malaysia located on the island of Borneo. The native population (71.6%) includes the Iban, Malay, Bidayuh, Melanau, and diverse smaller ethnic groups. The Chinese are the largest nonindigenous group (27.5%). We identified 392 newly diagnosed cases (292 males and 100 females) of NPC in 1996–1998 in Malaysian citizens, permanent residents of Sarawak. Age-standardized rates by sex and ethnic group were compared with the highest rates in the world. The age-adjusted rate (ASR) in Sarawak residents was 13.5/100,000 [95% confidence interval (CI) 12.2–15.0] and 6.2/100,000 (95% CI 5.7–6.7) in males and females, respectively. The risk in the Bidayuh people was 2.3-fold (M) and 1.9-fold (F) higher than the Sarawak average, and about 50% higher than that in Hong Kong—the highest recorded by any population-based registry for the same period. Local dietary habits, environmental exposures, and genetic susceptibility deserve investigation in this population.

Similar BCL-X but different BCL-2 levels in the two age groups of north African nasopharyngeal carcinomas

Nasopharyngeal carcinomas (NPCs) are consistently associated with the Epstein-Barr virus (EBV). As Bcl-2 and Bcl-X are co-expressed in EBV-transformed B-lymphocytes, we attempted to determine their status in malignant NPC cells. A retrospective series of 100 NPC specimens from untreated Tunisian patients was investigated by immuno-histochemistry. Twenty seven of the patients were below 30 years old and therefore classified in the "juvenile" form of north African NPCs. Bcl-2 and Bcl-X expression was assessed semi-quantitatively using a score based on the percentage of positive cells and staining intensity. Intense Bcl-X expression was detected in malignant cells of 100% biopsy samples with similar scores for patients below 30 years or those aged 30 or over. Bcl-2 was detected in 89% biopsies but its expression differed considerably between the samples. The average Bcl-2 score was much lower for patients under 30 years (4.4+/-1.5 compared to 6.5+/-2 for older patients; P<10(-6)). Multivariate analysis demonstrated that no other clinical parameter, except the primary tumor size, was correlated to the Bcl-2 score. Bcl-X and Bcl-2 are co-expressed in 89% of NPCs whereas their expression is mutually exclusive in other head and neck carcinomas (particularly squamous cell carcinomas, SCC). The constantly high expression of Bcl-X is consistent with it being induced by the EBV protein Epstein-Barr nuclear antigen 1 (EBNA1), as recently reported in a murine model. The contrasted levels of Bcl-2 expression in the two age groups strengthen the hypothesis that these clinical forms result from distinct oncogenic mechanisms.

Cytogenetic and molecular analysis of a family with three brothers afflicted with germ-cell cancer

A thorough cytogenetic investigation and an analysis of detailed questionnaires were performed in a family with three brothers afflicted with germ-cell tumors (GCTs), in an attempt to detect a congenital factor related either to a hereditary genetic background or an environmental/lifestyle influence. One brother had an intracranial tumor in the pineal region and the two others had testicular tumors. Peripheral blood was studied by traditional karyotyping, multicolor-FISH, high-resolution comparative genomic hybridization (HR-CGH), and molecular analysis of selected loci on sex chromosomes (Yq11 region, TSPY, and the androgen receptor gene); however, no abnormalities were detected. The HR-CGH analysis of microdissected histological components of the overt tumors and the adjacent carcinoma in situ demonstrated a pattern of genomic imbalances characteristic for sporadic GCTs, including gain of 12p. The questionnaire and interview revealed a history of different cancers in the extended family, and a possible in utero and/or infantile exposure of the three brothers with GCTs to compounds suspected of endocrine-disrupting properties. Although no genetic aberration was detected in this family, we suspect the presence of a recessive hereditary factor pre-disposing to cancer, which probably was manifested as GCTs in the three brothers because of an adverse effect of an environmental factor on the early germ-cell differentiation.

Age at immigration and duration of stay in relation to risk for testicular cancer among Finnish immigrants in Sweden

Although the incidence of testicular cancer is increasing, substantial differences in incidence between countries and populations exist. These differences cannot be explained solely by genetic differences, but environmental exposures, particularly early exposures, have been implicated in the etiology of testicular cancer. To assess whether early exposures contribute to the incidence of testicular cancer, we identified 93 172 Finnish men who immigrated to Sweden between 1969 and 1996 and followed them for the occurrence of testicular cancer. The risk of testicular cancer was lower for Finnish immigrants to Sweden than for the Swedish general population (standardized incidence ratio [SIR] = 0.34, 95% confidence interval [CI] = 0.21 to 0.53). The reduced risk was associated with both seminomas and non-seminomas. Neither age at immigration nor duration of stay in Sweden had any impact on the reduced risk. Although the type of environmental exposures remains unknown, the results strongly indicate that early exposures are major determinants for testicular cancer.

Infertility and environmental pollutants

While it has long been known that female fertility is impaired by oestrogen exposure, it is unclear whether environmental pollutants with weak oestrogenic effects are sufficiently potent and prevalent to have biological effects in humans. Male fertility, or sperm concentration at least, appears to have deteriorated, and there is substantial spatial variation at both national and global level, as well as a genetic component. Sperm morphology and motility are implicated too. There is good evidence for an increase in testicular cancer, and possibly in other conditions that certain spatial characteristics plus evidence on heritability suggest are linked to impaired spermatogenesis. A candidate agent would need to have started increasing in the early 20th century. Weak environmental oestrogens are not responsible. Candidates include agents affecting endogenous maternal oestrogen levels, environmental anti-androgens (although these cannot explain the epidemiological findings), and dioxin and related compounds. Genetic damage should be considered as a unifying hypothesis, possibly focused on the Y-chromosome.

Pathogenic roles for Epstein-Barr virus (EBV) gene products in EBV-associated proliferative disorders

Epstein-Barr virus (EBV) is associated with a still growing spectrum of clinical disorders, ranging from acute and chronic inflammatory diseases to lymphoid and epithelial malignancies. Based on a combination of in vitro and in vivo findings, EBV is thought to contribute in the pathogenesis of these diseases. The different EBV gene expression patterns in the various disorders, suggest different EBV-mediated pathogenic mechanisms. In the following pages, an overview of the biology of EBV-infection is given and functional aspects of EBV-proteins are discussed and their putative role in the various EBV-associated disorders is described. EBV gene expression patterns and possible pathogenic mechanisms are discussed. In addition, expression of the cellular genes upregulated by EBV in vitro is discussed, and a comparison with the in vivo situation is made.

Cancer risks among long-standing spouses

We estimated risks for concordant and discordant cancers in spouses in order to quantify cancer risks from the shared environment. The study was restricted to spouses who had one or more children in common and who lived together for at least 15 years after the first child's birth. The nation-wide Family-Cancer Database was used as the source of family and cancer data. Standardised incidence ratios were calculated for concordant and discordant cancers in spouses after 50 years of age. Among the 18 cancer sites considered, only three sites, stomach, lung and bladder, showed concordant increases of cancer among spouses, standardised incidence ratios ranging only from 1.19 to 1.38. Additionally, gastric and pancreatic cancer were associated among spouses, as did many cancers which were related to tobacco smoking or human papilloma virus infection. By contrast, standardised incidence ratios of colon, rectal, renal and skin cancers showed no increases among spouses. Shared lifestyle among family members seems to explain only a small proportion of familial cancer susceptibility. Because lifestyles are likely to differ more between parents and offspring than between spouses, familial cancer risks between parents and offspring are even more likely to be due to heritable than environmental effects.

Cancer risks in second-generation immigrants to Sweden

We used the nationwide Swedish Family-Cancer Database to analyze cancer risks in Sweden-born descendants of immigrants from European and North American countries. Our study included close to 600,000 0-66-year-old descendants of an immigrant father or mother. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for 17 cancer sites using native Swedes as a reference. All cancer was marginally below the Swedish incidence in offspring of immigrant origin. Decreased SIRs were observed for breast cancer among Norwegian descendants, melanoma among descendants of Hungarian fathers and ovarian and bladder cancer among descendents of Finnish mothers, all consistent with the difference in cancer incidence between Swedes and the indigenous populations. Cervical cancer was increased in daughters of Danish men, whereas thyroid cancer and non-Hodgkin's lymphoma were in excess in offspring of parents of Yugoslav and Asian descent. Even these results agreed with the high incidence rates in parents compared to Swedes, except that for non-Hodgkin's lymphoma other explanations are needed; these may be related to immune malfunction. Comparison of the results between the first- and the second-generation immigrants suggest that the first 2 decades of life are important in setting the pattern for cancer development in subsequent life. Birth in Sweden sets the Swedish pattern for cancer incidence, irrespective of the nationality of descent, while entering Sweden in the 20s is already too late to influence the environmentally imprinted program for the cancer destiny.

Cancer risks in childhood and adolescence among the offspring of immigrants to Sweden

We used the nation-wide Swedish Family-Cancer Database to analyse the risk of nervous system tumours, leukaemia and non-Hodgkin's lymphoma in age groups 0-4 and 0-19 years among Swedish-born offspring of immigrants. The study included 850 000 individuals with an immigrant background, including European, Asian and American parents. We calculated standardised incidence ratios for the above three malignancies using Swedish offspring as a reference. Subjects were grouped by region or by selected countries of parental origin. No group differed significantly from Swedes in the occurrence of nervous system neoplasm or leukaemia. Offspring of Yugoslav fathers (SIR 2.27) and Turkish parents were at increased risk of non-Hodgkin's lymphoma. The highest risk was noted for non-Hodgkin's lymphoma among young offspring (0-4 years) of two Turkish parents (6.87). The currently available limited data on rates for childhood non-Hodgkin's lymphoma in these countries do not explain the risk in the offspring of immigrants. Yugoslavs and Turks are recent immigrant groups to Sweden, and their offspring have been subject to much population mixing, perhaps leading to recurring infections and immunological stimulation, which may contribute to their excess of lymphomas.

Estimates of cancer incidence and mortality in Europe in 1995

Cancer incidence and mortality estimates for 1995 are presented for the 38 countries in the four United Nations-defined areas of Europe, using World Health Organization mortality data and published estimates of incidence from national cancer registries. Additional estimation was required where national incidence data was not available, and the method involved incorporating the high quality incidence and mortality data available from the expanding number of population-based cancer registries in Europe. There were an estimated 2.6 million new cases of cancer in Europe in 1995, representing over one-quarter of the world burden of cancer. The corresponding number of deaths from cancer was approximately 1.6 million. After adjusting for differing population age structures, overall incidence rates in men were highest in the Western European countries (420.9 per 100,000), with only Austria having a rate under 400. Eastern European men had the second highest rates of cancer (414.2), with extremely high rates being observed in Hungary (566.6) and in the Czech Republic (480.5). The lowest male all-cancer rate by area was observed in the Northern European countries, with fairly low rates seen in Sweden (356.6) and the UK (377.8). In contrast to men, the highest rates in women were observed in Northern Europe (315.9) and were particularly high in Denmark (396.2) and the other Nordic countries excepting Finland. The rates of cancer in Eastern European women were lower than in the other three areas, although as with men, female rates were very high in Hungary (357.2) and in the Czech Republic (333.6). There was greater disparity in the mortality rates within Europe--generally, rates were highest in Eastern European countries, notably in Hungary, reflecting a combination of poorer cancer survival rates and a higher incidence of the more lethal neoplasms, notably cancer of the lung. Lung cancer, with an estimated 377,000 cases, was the most common cancer in Europe in 1995. Rates were particularly high in much of Eastern Europe reflecting current and past tobacco smoking habits of many of its inhabitants. Together with cancers of colon and rectum (334,000), and female breast (321,000), the three cancers represented approximately 40% of new cases in Europe. In men, the most common primary sites were lung (22% of all cancer cases), colon and rectum (12%) and prostate (11%), and in females, breast (26%), colon and rectum (14%) and stomach (7%). The number of deaths is determined by survival, as well as incidence; by far the most common cause of death was lung cancer (330,000)--about one-fifth of the total number of cancer deaths in Europe in 1995. Deaths from cancers of the colon and rectum (189,000) ranked second, followed by deaths from stomach cancer (152,000), which due to poorer survival ranked higher than breast cancer (124,000). Lung cancer was the most common cause of death from cancer in men (29%). Breast cancer was the leading cause of death in females (17%). Cancer registries are a unique source of information on cancer incidence and survival, and are used here with national mortality to demonstrate the very substantial burden of cancer in Europe, and the scope for prevention. Despite some provisos about data quality, the general patterns which emerge in Europe verify the role of past exposures and interventions, and more importantly, firmly establish the need for cancer control measures which target specific populations. In particular, there is a clear urgency to combat the ongoing tobacco epidemic, now prevalent in much of Europe, particularly in the Eastern countries.

Study of human leukocyte antigen class I phenotypes in Moroccan patients with nasopharyngeal carcinoma

Previous reports demonstrated an association between the human leukocyte antigen (HLA) and risk for nasopharyngeal carcinoma (NPC) among the Chinese in Singapore, a population with a high incidence of this malignancy. In our study, we assess the association between HLA and NPC in Morocco, a median-prevalence area for this cancer, where NPC presents the particularity of also affecting young individuals. Using the standard microlympho-cytotoxicity test, we typed a total of 154 Moroccan NPC patients and 257 unrelated healthy controls for their HLA-A and B antigens. The results of these analyses show that the frequencies of HLA-A10, HLA-B13 and HLA-B18 were found to be higher in the NPC group than in the control group, whereas HLA-A9 was associated with a decreased risk. After correction for the number of specificities tested, these differences were statistically significant only for HLA-B18 (corrected p value [pc] < 0.023, relative risk [RR] = 4.14) and HLA-A9 (pc < 0.023, RR = 0.45). The comparison of the distribution of the HLA antigens in younger and older cohorts of patients shows that the incidence of HLA-A10 and HLA- B18 was higher in the older group, whereas the frequencies of HLA-A19 and HLA-B13 were significantly higher in younger patients compared with controls. The presence of both HLA-A19 and HLA-B13 phenotypes correlated with an increased risk of developing NPC among overall patients compared with controls. According to the sex distribution, increased frequency of HLA-B18 was found in male and female NPC patients compared with controls, whereas the frequency of HLA-A10 was higher only in male NPC patients compared with controls.

Frequency and genome load of Epstein-Barr virus in 509 breast cancers from different geographical areas

Since the few data exploring a possible association between Epstein-Barr virus (EBV) and breast cancer are conflicting, we investigated this association together with the influences of geographical areas. 509 breast cancers were sampled from areas with varying risks of nasopharynx carcinoma (NPC) such as North Africa (Algeria and Tunisia, high-risk area); southern France (Marseille, intermediate-risk area); and northern Europe (northern France, the Netherlands and Denmark; low-risk areas). Polymerase chain reaction (PCR) of a subregion of EBV BamHIC encoding the EBERs demonstrated that 31.8% of the tumours contained the viral genome. No significant differences were observed among the geographical areas. However, positive samples showed higher loads of the EBV genome in the NPC high- and intermediate-risk areas than in the low-risk areas. EBV type 1 was the dominant strain. In situ hybridization studies using a(35)S-labelled riboprobe for EBER1 and a laser capture microdissection, combined with quantitative PCR, showed that EBV localization was restricted to some tumour epithelial cell clusters. EBV could not be detected in the stroma. Considering the whole population covered, the presence of the EBV genome was not correlated with age, menopausal status, tumour, size, nodal status or histological grade.