Rhabdomyosarcoma in infants under one year of age: Experience of the institut Gustave‐Roussy

Abstract
Forty‐three infants under 1 year of age (median 4 months) with rhabdomyosarcoma (RMS), representing 11% of all childhood RMS seen over the same period, were treated and followed between 1955 and 1984 at our institute. Compared to the 340 older children (1‐16 years of age), there were no significant differences in male/female ratio, primary site, or clinical stage, but there was a higher frequency of alveolar and poorly differentiated histologic subtypes in infants aged under 1 year (P = 0.05 and P < 0.001, respectively) and increased frequency of botryoid RMS in older children (P < 0.02). Although children older than 1 year of age had a significantly higher complete remission rate (83% vs. 51%, P < 0.001), their 5 year overall survival (43%) was no different from that of infants under 1 year of age (35%). In the older group there was no survival difference between alveolar (38%) and nonalveolar (44%) histologic subtypes, but in infants younger than 1 year, alveolar subtype had a significantly poorer prognosis (13% vs. 47%, P = 0.01). Management of patients at this age group is difficult and major advances are needed to increase survival rates with a minimum of morbidity.