Children treated for soft tissue sarcomas at greater risk of second cancers

A new study has found that although children treated for soft tissue sarcomas are surviving longer than they did in the past, they have an increased risk for second cancers, especially when initial treatment combined radiation and chemotherapy. This is according to analysis of data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute.

In their report, Dr. Rochelle E. Curtis and associates at the National Cancer Institute in Bethesda, Maryland, say other studies have also suggested this increased risk but those studies have been small in size, so she and her team conducted a large study to follow 1499 children who survived at least 1 year after a soft tissue sarcoma diagnosis - either rhabdomyosarcoma, fibromatous neoplasms, and other specified soft tissue sarcomas - between 1973 and 2000. The rates of malignancy were then compared with those expected in the general population based on gender, race, age, and calendar year.

Twenty seven of the children developed 28 second primary cancers, compared with the expected 4.5 cases. The most common second malignancies included acute myeloid leukaemia, cutaneous melanoma, and cancers of the oral cavity, breast, bone, and soft tissue.

This means that the relative risk was higher during the first 5 years of follow-up, about 12 times higher than expected, but decreased to 5-fold thereafter.

Other factors associated with higher risk included treatment since 1985 rather than earlier, age less than 10 years versus older and combined radiotherapy and chemotherapy compared with surgery alone.

The researchers found that the risk associated with combined therapy was highest for patients with fibromatous neoplasms, for whom the rate of second cancers was increased more than 70 times.

Dr. Curtis's group concluded that ' further studies of childhood soft tissue sarcoma survivors are needed to evaluate the independent and combined effects of therapy and genetic susceptibility in the development of various types of second cancers'.