Children of farmers face an increased risk of developing Ewing’s sarcoma - tumors of bone and soft tissues that mainly affect children and adolescents - according to a new report.

Patricia C. Valery from Queensland Institute of Medical Research, Australia said that many studies of childhood cancers have supported a link between parental occupation in farming and the subsequent development of cancer in their offspring.

“Nevertheless, the biological mechanisms that underlie such associations remain uncertain,” she said.

Valery and her colleagues pooled findings from a total of seven studies that have looked into Ewing’s sarcoma (ES) and the Ewing’s sarcoma family of tumors (ESFT).

The pooled analysis showed an increase in ES risk for children whose mothers or fathers worked on farms, the investigators report in the International Journal of Cancer, with a stronger association if farm work occurred around the time of conception and during gestation.

The increase in risk was higher with maternal involvement in farm work than with paternal exposure, and the risk increased with increasing number of years of parental farming occupation after the child was born.

Results of ESFT analysis were similar, the investigators report.

“Overall, the evidence from our study plus other studies on ES supports the hypothesis of an association between ES, farm residency, and parental occupation in farming,” Valery concluded. However further understanding will require a degree of detailed study “that is not easily accomplished.”

SOURCE: International Journal of Cancer, July 10, 2005.