Childhood leukemia in south-west Sardinia (Italy).

AIM AND BACKGROUND: Public concern on an increased incidence of childhood leukemia in SW Sardinia prompted the authors to an epidemiological investigation. METHODS: Incident childhood neoplasms observed in the Cagliari province (Sardinia--Italy) in 1974-1989 were registered. Expected cases of the most frequent childhood cancers were calculated for each town, based on the sex-and age-specific incidence rates in the province. RESULTS: An excess risk of childhood acute lymphoblastic leukemia (ALL) was observed in Carbonia, a town located in the SW part of the province. The risk was highest in 1983-85, when 7 cases occurred versus 0.8 expected (RR = 8.7; 95% C.I. = 4.6, 16.3). No spatial clustering of ALL cases was observed within the town. CONCLUSIONS: A significantly higher than expected incidence of childhood ALL was observed in the town of Carbonia in 1983-85. In alternative to chance, possible exposure to environmental pollutants from a near industrial settlement is discussed as the cause of the observed excess, but it is far to be proven. Other hypotheses, including a viral infection in a population with increased susceptibility, as suggested for new urban settlements, cannot be discarded.

Analysis of risk factors in a cluster of childhood acute lymphoblastic leukemia.

A case-control investigation of childhood acute lymphoblastic leukemia was conducted in the town of Carbonia (Sardinia, Italy). Parents of 9 cases diagnosed between 1980 and 1989 and 36 controls were interviewed at their respective residences. None of the risk factors analyzed was associated significantly with childhood acute lymphoblastic leukemia. The following were associated with an increased risk for childhood acute lymphoblastic leukemia: parents born outside of Carbonia, family history of cancer, alcohol consumption by fathers that exceeded 60 g/d, exposure of fathers to solvents at their workplaces, maternal smoking, use of antinausea medications during pregnancy, and presence of a well in the backyard. Chance and recall bias likely played a role in generating positive associations. The increases in childhood leukemia risk associated with the presence of a well and with use of antinausea medications during pregnancy are consistent with previous reports and require further investigation.

Childhood Acute Lymphoblastic Leukemia: A Cluster in Southwestern Sardinia (Italy).

In response to public concern about an increase in the incidence of leukemia among children in southwestern Sardinia (Italy), incident cases of childhood cancer (ages 0-14) were ascertained among residents in the province of Cagliari, which comprises all of southern Sardinia, in 1974-89. Completeness of the ascertainment of leukemia cases was validated by comparison with estimates derived from official statistics of mortality and survival curves. A significant excess risk of childhood acute lymphoblastic leukemia (cALL) was found for children residing in the town of Carbonia. The risk was highest in 1983-85, when seven cases occurred versus 0.8 expected. No birth-cohort effect was observed. The cALL incidence rate was significantly higher among children born and residing in Carbonia than among children born in Carbonia but residing elsewhere. However, the cALL cases did not cluster within the town of Carbonia. The proximity of the largest industrial settlement in the region of Sardinia raised the suspicion that environmental pollution was responsible for the observed excess. Information about industrial emissions from this settlement prior to the appearance of the cALL cluster was not sufficient to reject or confirm the hypothesis.