Long-term results in childhood rhabdomyosarcoma: A report from the Italian cooperative study RMS 79

Background: The results obtained by protocols for children with rhabdomyosarcoma (RMS) have improved in recent decades. Survival curves usually reach a plateau 3 years after the diagnosis, suggesting that long-term survival can be expected, but late events are known to occur. We analyzed the long-term results of the RMS 79 protocol to investigate the type and impact of such events. Procedure: From 1979 to 1987, 163 children with RMS diagnosed at 21 Italian institutions were registered. Each institution was contacted every year to record patients' status after the end of treatment. When patients were lost to follow-up, their status was checked by inquiring at the Registry Offices of the towns of residence and the cause of death or occurrence of second cancers was investigated by contacting the patients or their family by phone. Results: Overall, 16 patients had late events, that is, 7 tumor recurrences, 6 second tumors, and 3 deaths due to treatment-related complications. The overall survival rates dropped from 62.6 at 3 years to 52.8 at 20 years. By multivariate analysis, the characteristics influencing long-term survival were histology, tumor site and size, and IRS group. Factors predictive of any kind of late event were tumor site and IRS group. Conclusions: Major late events can significantly affect the long-term survival of children with RMS. Modern protocols should provide for a much longer follow-up than is usually considered to confirm the results achieved and enable possible correlations between primary treatment and late events to be investigated.