Childhood leukaemia incidence below the age of 5 years near French nuclear power plants

A recent study indicated an excess risk of leukaemia among children under the age of 5 years living in the vicinity of nuclear power plants in Germany. We present results relating to the incidence of childhood leukaemia in the vicinity of nuclear power plants in France for the same age range. These results do not indicate an excess risk of leukaemia in young children living near French nuclear power plants.

UV radiation exposure, skin type and lymphoid malignancies: results of a French case-control study

OBJECTIVES

Investigating the relationship between skin type, UV exposure, and lymphoid malignancies (LM).

METHODS

We conducted a hospital-based case-control study in France, including 813 incident cases of non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HL), lymphoproliferative syndrome (LPS) or multiple myeloma and 748 controls.

RESULTS

Positive associations between HL and blond/red hair (OR = 1.8 [0.8-3.8]), very fair/fair skin (OR = 1.6 [1.0-2.5]) were observed. High propensity to burn was associated with HL (OR = 1.5 [1.0-2.2]) and LPS (OR = 1.4 [1.0-2.1]). Poor ability to tan was significantly associated with HL (OR = 1.7 [1.0-2.8]). Having light hair with high propensity to burn was associated with NHL (OR = 1.5 [0.9-2.5]) and significantly with HL (OR = 3.4 [1.4-8.4]). Having dark hair with high propensity to burn was significantly associated with LPS (OR = 1.5 [1.0-2.2]). The associations with HL and NHL were significant for men only, with significant interactions. Outdoors activities since leaving school or in the last decade were not related to LM. Only an almost negative trend was observed. Prior exposure to artificial UV was not associated with LM.

CONCLUSION

These results suggest a positive association between the most reactive and palest skin types and NHL or HL in men and do not rule out a slight negative relationship between UV exposure and LM.

Up-to-date monitoring of childhood cancer long-term survival in Europe: leukaemias and lymphomas

BACKGROUND

In recent decades, following the introduction of effective chemotherapy, the prognosis of children with leukaemia and lymphoma has dramatically improved, but data reflecting further possible improvement achieved in the 1990s are scarce.

METHODS

Using the Automated Childhood Cancer Information (ACCIS) database, we carried out a period analysis of 10-year survival for the 1995-99 period. Analyses were carried out by diagnostic groups, age-group at diagnosis, sex and four European regions.

RESULTS

Ten-year survival estimates for the 1995-99 period were 73% for any type of leukaemia, 78% for acute lymphoid leukaemia and 52% for acute non-lymphocytic leukaemia. The corresponding 10-year survival rates for all types of lymphomas, Hodgkin lymphoma, and non-Hodgkin lymphoma were 84, 91 and 79%, respectively. These figures are much higher than those obtained by traditional (cohort-based) methods of survival analysis. A large difference in prognosis is still observed between the East and other parts of Europe.

CONCLUSION

Major improvement in prognosis for children with leukaemia or lymphoma has been ongoing in Europe during the 1990s, but further monitoring and investments are required to remove the large regional differences between European regions.

Hodgkin's disease incidence and survival in European children and adolescents (1978-1997): report from the Automated Cancer Information System project

This paper reports the geographical patterns and time trends of incidence and survival of Hodgkin's disease (HD) in children and adolescents in Europe over the period 1978-1997. Data on 4230 HD cases were gathered from 62 paediatric or general cancer registries in 19 European countries by the Automated Cancer Information System (ACCIS). European annual incidence rates in 1988-1997 were estimated at 5.8 per million in children (world age-standardised) and at 29.7 per million in adolescents, with higher rates in the East and South. Incidence rates increased steeply with age, while the male predominance, marked for the youngest children, vanished in the highest age groups. Over the period 1978-1997 incidence rates increased in age groups 10-14 years (+1% per year) and 15-19 years (+3.5% per year), mainly due to the nodular sclerosis subtype. Age and sex distribution of cases remained unchanged with time. The overall 5-year survival rate was higher in children (93%, 95% confidence interval (CI) 92-94) than in adolescents (89% (95% CI 87-91)) for the period 1988-1997. Five-year survival increased significantly in all regions from 87% to 93% in children and from 80% to 88% in adolescents between 1978-1982 and 1993-1997. In future, detailed documentation of cases in the cancer registries with respect to standardised diagnostic subtypes, stage of extension, and treatments, will help to refine interpretation of international and temporal variations in incidence and survival.

Childhood leukaemia incidence around French nuclear installations using geographic zoning based on gaseous discharge dose estimates

The present study investigated for the first time the incidence of childhood leukaemia (1990–2001) around French nuclear installations using a geographic zoning based on estimated doses to the red bone marrow due to gaseous radioactive discharges. The observed number of cases of acute leukaemia (O=750) in 40 km² centred on 23 French nuclear installations between 1990 and 2001 was lower than expected (E=795.01), although not significantly so (standardised incidence ratio SIR=0.94, 95% confidence interval=(0.88–1.01)). In none of the five zones defined on the basis of the estimated doses was the SIR significantly >1. There was no evidence of a trend in SIR with the estimated doses for all the children or for any of the three age groups studied. This study confirmed that there was no evidence of an increased incidence of childhood leukaemia around the 23 French nuclear sites.

Spatial and space-time clustering of childhood acute leukaemia in France from 1990 to 2000: a nationwide study

This study aimed to investigate the spatial and space–time distributions of cases of childhood acute leukaemia (CL) during 1990–2000 over the whole French territory. A global spatial heterogeneity and a spatial autocorrelation were first considered using the methods proposed by Potthoff and Whittinghill, Moran and Rogerson methods. The presence of space–time interaction between the places of residence and the dates of diagnosis was investigated with the Knox's test. Finally, the Kulldorff's statistic permitted to scan the whole territory in search for localised clusters. Two time periods were considered (1990–1994, 1995–2000). Overall, a statistically significant spatial heterogeneity of a very small magnitude was observed in the incidence of CL over 1990–1994, but neither over 1995–2000 nor over the whole time period. Moreover, a significant overdispersion of 5.5% was evidenced for 0–4 year children living in isolated areas with more than 50 inhabitants per km². Cases older than 10 years living in the same area at diagnosis also tended to cluster within 6 months.

Population-mixing at the place of residence at the time of birth and incidence of childhood leukaemia in France

The association between the risk of childhood leukaemia before age 7 years and population-mixing at the place of residence at birth was investigated by retrospectively considering all the children born in mainland French communes between 1st January 1990 and 31st December 1998. An increased risk of acute lymphoblastic leukaemia was found with higher levels of migration for children residing at birth in isolated communes with a population density > or =50 people per km2 (SIRR = 2.59, 95% CI: 1.48-4.49). No association was observed with lower population densities. For children residing in non-isolated communes at birth, the results were similar but less marked. The risk tended to increase only for population densities > or =5000 people per km2 (SIRR = 1.57, 95% CI: 0.99-2.52). The findings are consistent with epidemic models and support the hypothesis of an infectious aetiology relating to population-mixing. Population density may be seen as an indicator of the opportunity of contacts between inhabitants and should therefore be taken into account when investigating an infectious hypothesis. This is the first systematic study of population-mixing at the place of residence at the time of birth to be conducted on a national scale.

Survival in France after childhood acute leukaemia and non-Hodgkin’s lymphoma (1990–2000)

This article describes the survival after childhood acute leukaemia (AL) and non-Hodgkin's lymphoma (NHL) of French population aged less than 15 years. The French National Registry of Childhood Leukaemia and Lymphoma recorded 3995 cases of acute lymphoblastic leukaemia (ALL), 812 of acute myeloid leukaemia (AML) and 1137 of NHL over the period from 1990 to 2000. Overall survival rates at 5 years were 82% (95% CI 80-83), 58% (95% CI 54-61) and 87% (95% CI 85-89) for ALL, AML and NHL, respectively. Survival after AL increased from 77% (95% CI 75-80) in 1990-1992 to 85% (95% CI 83-87) in 1997-2000 for ALL and from 47% (95% CI 41-54) to 61% (95% CI 55-67) for AML. Among AL cases, children aged 1-4 years had the most favourable prognosis. Down's syndrome was associated with poor survival after ALL. No gender-related variations in survival were in evidence. The results reported herein are similar to those reported by other European registries and clinical trials.

Household exposure to pesticides and risk of childhood acute leukaemia

OBJECTIVES

To investigate the relation between childhood acute leukaemia and household exposure to pesticides.

METHODS

The study included 280 incident cases of acute leukaemia and 288 controls frequency matched on gender, age, hospital, and ethnic origin. The data were obtained from standardised face to face interviews of the mothers with detailed questions on parental occupational history, home and garden insecticide use, and insecticidal treatment of pediculosis. Odds ratios were estimated using unconditional regression models including the stratification variables parental socioeconomic status and housing characteristics.

RESULTS

Acute leukaemia was observed to be significantly associated with maternal home insecticide use during pregnancy (OR = 1.8, 95% CI 1.2 to 2.8) and during childhood (OR = 1.7, 95% CI 1.1 to 2.4), with garden insecticide use (OR = 2.4, 95% CI 1.3 to 4.3), and fungicide use (OR = 2.5, 95% CI 1.0 to 6.2) during childhood. Insecticidal shampoo treatment of pediculosis was also associated with childhood acute leukaemia (OR = 1.9, 95% CI 1.2 to 3.3).

CONCLUSION

The results reported herein support the hypothesis that various types of insecticide exposure may be a risk factor for childhood acute leukaemia. The observed association with insecticidal shampoo treatment of pediculosis, which has never been investigated before, requires further study.

Ecological association between indoor radon concentration and childhood leukaemia incidence in France, 1990–1998

The objective of this study was to evaluate the ecological association between indoor radon concentration and acute leukaemia incidence among children under 15 years of age in the 348 geographical units (zones d'emploi, ZE) of France between 1990 and 1998. During that period, 4015 cases were registered by the French National Registry of Childhood Leukaemia and Lymphoma. Exposure assessment was based on a campaign of 13 240 measurements covering the whole country. The arithmetic mean radon concentration was 85 Bq/m (range, 15-387 Bq/m) and the geometric mean, 59 Bq/m (range: 13-228 Bq/m). A positive ecological association, on the borderline of statistical significance (P=0.053), was observed between indoor radon concentration and childhood leukaemia incidence. The association was highly significant for acute myeloid leukaemia (AML) (P=0.004) but not for acute lymphocytic leukaemia (ALL) (P=0.49). The standardized incidence ratio (SIR) increased by 7, 3 and 24% for all acute leukaemia, ALL and AML, respectively, when radon concentration increased by 100 Bq/m. In conclusion, the present ecological study supports the hypothesis of a moderate association between indoor radon concentration and childhood acute myeloid leukaemia. It is consistent with most previous ecological studies. Since the association is moderate, this result does not appear inconsistent with the five published case-control studies, most of which found no significant association.

Incidence of childhood leukaemia in the vicinity of nuclear sites in France, 1990-1998

Overall, 670 cases (O) of childhood leukaemia were diagnosed within 20 km of the 29 French nuclear installations between 1990 and 1998 compared to an expected number (E) of 729.09 cases (O/E=0.92, 95% confidence interval (CI)=[0.85–0.99]). Each of the four areas defined around the sites showed non significant deficits of cases (0–5 km: O=65, O/E=0.87, CI=[0.67–1.10]; 5–10 km: O=165, O/E=0.95, CI=[0.81–1.10]; 10–15 km: O=220, O/E=0.88, CI=[0.77–1.00]; 15–20 km: O=220, O/E=0.96, CI=[0.84–1.10]). There was no evidence of a trend in standardised incidence ratio with distance from the sites for all children or for any of the three age groups studied. Similar results were obtained when the start-up year of the electricity-generating nuclear sites and their electric nuclear power were taken into account. No evidence was found of a generally increased risk of childhood leukaemia around the 29 French nuclear sites under study during 1990–1998.

Acute childhood leukaemia and environmental exposure to potential sources of benzene and other hydrocarbons; a case-control study

AIM

To analyse the association between potential environmental exposure to hydrocarbons and the risk of acute childhood leukaemia.

METHODS

A hospital based multicentre case control study, stratified on centre, age, and sex, with 280 leukaemia cases and 285 controls was carried out. Data were collected by a standardised interview of the mothers.

RESULTS

No clear association was seen between maternal occupational exposure to hydrocarbons during pregnancy and leukaemia, or between residential traffic density and leukaemia. There was an association between dwellings neighbouring a petrol station or a repair garage during childhood and the risk of childhood leukaemia (OR 4.0, 95% CI 1.5 to 10.3), with a duration trend. The association, which appeared particularly strong for acute non-lymphocytic leukaemia (OR 7.7, 95% CI 1.7 to 34.3), was not altered by adjustment for potential confounding factors.

CONCLUSIONS

Results showed an association between acute childhood leukaemia and dwellings neighbouring auto repair garages and petrol stations, which are benzene emitting sources. These findings could be due to chance, although the strength of the association and the duration trend are arguments for a causal association.

Incidence of childhood leukaemia and non-Hodgkinʼs lymphoma in France: National Registry of Childhood Leukaemia and Lymphoma, 1990–1999

The French National Registry of Childhood Leukaemia and Lymphoma (NRCL) covers the whole French mainland population aged less than 15 years (approximately 11 million children) for all childhood haematopoietic tumours since 1 January 1990, except Hodgkin's disease, which has been registered since 1 January 1999. During the period from 1990 to 1999, 5757 cases of leukaemia, lymphoma and myelodysplastic syndrome were registered in the NRCL, with an average of 2.5 sources per case. The age-standardized incidence rates per million per year were 43.1 for leukaemia (34.3 for acute lymphoblastic leukaemia, 7.1 for acute myeloblastic leukaemia, 0.6 for chronic myeloid leukaemia and 0.5 for chronic myelomonocytic leukaemia), 8.9 for non-Hodgkin's lymphomas and 6.7 for Hodgkin's disease. Down's syndrome was present in 110 cases of acute leukaemia (2.5%) and three cases of non-Hodgkin's lymphoma (0.3%). The incidence of acute lymphoblastic leukaemia showed a typical peak at age 2 years for girls and 3 years for boys. The incidence rates of leukaemia and non-Hodgkin's lymphoma did not show any temporal trends over the 10 year period.

Association of polymorphisms in the Tau and Saitohin genes with Parkinson's disease

BACKGROUND

The Saitohin gene has recently been identified in intron 9 of the Tau gene. Because an association between Parkinson's disease and Tau has been described, Saitohin represents a candidate gene for Parkinson's disease.

OBJECTIVE

To test these two genes for their association with Parkinson's disease in a large community based case-control study.

RESULTS

Cases (n = 208) were more often homozygotes for the Tau H1 haplotype than controls (n = 483; odds ratio (OR) = 1.71 (95% confidence interval, 1.20 to 2.43); p = 0.003), and the saitohin Q allele was in complete linkage disequilibrium with the H1 haplotype. This association was stronger among cases with Parkinson's disease onset below 65 years (< or =65 years: OR = 2.52 (1.49 to 4.25); p<0.001) than among those with older onset (>65 years: OR = 1.20 (0.73 to 1.98); p<0.47).

CONCLUSIONS

The data suggest that there is a functional polymorphism at this locus involved in Parkinson's disease.

Infectious diseases in the first year of life, perinatal characteristics and childhood acute leukaemia

The objective of the present study was to investigate the role of early common infections and perinatal characteristics in the aetiology of childhood common leukaemia. A case–control study was conducted from 1995 to 1998 in France, and included 473 incident cases of acute leukaemia (AL) (408 acute lymphoblastic leukaemia (ALL), 65 acute myeloid leukaemia (AML) age-, sex- and region-matched with 567 population-based controls. Data on the medical history of the child and his/her environment were collected using self-administered questionnaires. Analyses were conducted using nonconditional logistic regression. A slight negative association with early infections was observed (OR=0.8; 95% CI (0.6–1.0)). The association was stronger for early gastrointestinal infections. Early day-care was found to be associated with a decreased risk of AL (OR=0.6; 95% CI (0.4–0.8) and OR=0.8; 95% CI (0.5–1.2) for day-care starting before age 3 months and between 3 and 6 months, respectively). No association with breast-feeding was observed, irrespective of its duration. A birth order of 4 or more was associated with a significantly increased risk of AL (OR=2.0; 95% CI (1.1–3.7) with ALL). A history of asthma was associated with a decreased risk of ALL (OR 0.5; 95% CI (0.3–0.90). Although the results regarding birth order and breast-feeding do not fit with Greaves' hypothesis, the study supports the hypothesis that early common infections may play a protective role in the aetiology of childhood leukaemia, although this effect was not more marked for common ALL.

Day-care, early common infections and childhood acute leukaemia: a multicentre French case-control study

We conducted a case-control study to investigate the role of early infections in the aetiology of childhood acute leukaemias. The study included 280 incident cases (240 acute lymphoblastic leukaemia and 40 acute non-lymphoblastic leukaemia) and 288 hospital controls, frequency matched by age, gender, hospital, catchment area of the hospital and ethnic origin. Data were obtained from standardised face-to-face interviews of the mothers. The interviews included questions on early common infections, day-care attendance, breast-feeding, birth order and infantile diseases. Odds ratios were estimated using an unconditional regression model including the stratification variables, parental socio-economic status and perinatal characteristics. Birth order was not associated with childhood leukaemia (acute lymphoblastic or acute non-lymphoblastic). A statistically-significant inverse association was observed between childhood leukaemia and day-care attendance (odds ratio=0.6, 95% Confidence Interval=(0.4-1.0)), repeated early common infections (> or = 4 per year before age two, odds ratio=0.6 (0.4-1.0)), surgical procedures for ear-nose-throat infections before age two (odds ratio=0.5 (0.2-1.0)) and prolonged breast-feeding (> or = 6 months, odds ratio=0.5 (0.2-1.0)). In the multivariate model including day-care attendance, early common infections and breast-feeding, results concerning breast-feeding remained unchanged. A statistically significant interaction between day-care attendance and repeated early common infections was observed. When the interaction was taken into account, the simple effects of day-care and early common infections disappeared (odds ratio=1.1 (0.5-2.3) and odds ratio=0.8 (0.5-1.3), respectively) while the joint effect of day-care attendance and early common infections was negatively associated with childhood leukaemia (odds ratio=0.3 (0.1-0.8)). All the above associations were observed both for acute lymphoblastic leukaemia and acute non-lymphoblastic leukaemia. Our results support Greaves' hypothesis, even though they are not specific of common leukaemia.