August 4 (HealthDay News) -- Immunotherapy shows promise in treating children with high-risk sarcomas, according to a U.S. National Institute of Health pilot study.

The study involved a new dendritic vaccine as well as a standard flu vaccine to potentially strengthen the immune system following chemotherapy.

While the dendritic vaccine didn't perform as well as hoped, children did respond well to the standard flu vaccine. This suggests that boosting immune function in children with sarcoma may be an effective approach. The dendritic vaccine included peptides derived from each patient's individual cancer in a way designed to alert the system to the unique genetic alteration on the cancer cells.

The study of 52 patients with recurrent and/or metastatic Ewing's sarcoma or alveolar rhabdomyosarcoma also found that those who received immunotherapy had better-than-normal survival. Patients who received immunotherapy had a 43 percent five-year overall survival, compared to 31 percent for those who didn't receive immunotherapy.

Overall, outcomes for these tumors have improved over the past 40 years, but there hasn't been substantial improvement for patients with recurrent or metastatic disease, noted the study's senior investigator, Dr. Crystal Mackall, of the National Cancer Institute's Pediatric Oncology Branch.

"This study shows that immunotherapy is safe and well-tolerated, and could ultimately be beneficial for this high risk population," she said in an American Association for Cancer Research news release. "We now know that the immune system of patients recovering from chemotherapy is malleable, so we just need to find the best immunological approach to exploit this window of opportunity."

The study was published in the Aug. 1 issue of the journal Clinical Cancer Research.

SOURCE: American Association for Cancer Research, news release, Aug. 1, 2008