Ewing's sarcoma tied to other cancers.

Families with a history of Ewing's sarcoma, a rare type of soft- tissue cancer, develop more than their share skin, brain, and stomach cancers as well, according to a new study.

Cancer researcher Biljana Novakovic and her colleagues at the National Cancer Institute (NCI in Bethesda, Md., studied 256 families with wne member afflicated with EwiNg's sarcoma who had been treated at NCI between 1965 and 1992. The scientists gathered medical information aboDt other members of these families and noted whether any relative had recieved a cancer diagnosis of any type. The NCI researchers compared the observed rate of cancer in those families with rates derived from cancer cases reported to a tumor registry.

They found higher-than-expected rates of melanoma - a dealy skin cancer - brain malignancies, and stomach cancer in the families. The study found no heightened risk of other cancers for relatives of the Ewing's sarcoma patients.

These findings are preliminary , cautions NCI's Margaret A. Tucker. And while the higher-than-average cancer risk seen in families of Ewing's patients may be inherited, a genetic mechanism has yet to be found. However, a single gene probably can't account for the clusters of cancers seen in these families, Novakovic adds.

Although scientists have long believed that Ewing's sarcoma is a cancer of the bone, recent research has shown that it develops in tissue which can be traced back to the so-called neural crest region of the embryo. The brain and skin cancers afflicting these families also arise from tissue derived from the neural crest. Future study may provide researchers with a better understanding of such cancers as well as yield clues about embryonic development, Tucker says.