An unresolved issue in rhabdomyosarcoma treatment: The duration of chemotherapy.

Clinical trials have tested different chemotherapy regimens to improve outcome for patients with rhabdomyosarcoma (RMS), but therapy duration has never been explicitly evaluated. North American trials evolved from longer (104 weeks) to shorter duration (24-42 weeks). In Europe, treatment duration similarly evolved from 35 to 48 to 22 weeks for lower risk patients and from 56 to 72 to 27 weeks for higher risk patients. There was no evidence that chemotherapy duration influenced outcome over time. The recent RMS2005 trial showed an improved survival with the addition of 24 weeks of low-dose chemotherapy. Treatment duration remains a question to be addressed in future trials.