Rhabdomyosarcoma in infants younger than 1 year: a report from the Children's Oncology Group

Abstract

Background: Rhabdomyosarcoma (RMS), the most common soft-tissue sarcoma in children, occurs less commonly in infants. Historically, poorer outcomes have been reported for infants diagnosed with RMS than for older children.

Methods: The authors analyzed the characteristics, treatment administered, outcomes, and patterns of failure for infants aged < 1 year with nonmetastatic RMS who received multimodal therapy on Intergroup Rhabdomyosarcoma Study (IRS) protocols IRS-IV, D9602, and D9803.

Results: Seventy-six infants with nonmetastatic RMS were treated on the 3 protocols from 1991 to 2005. Their median age was 7.4 months (range, 0.1-12 months). Tumor histology included embryonal (57%), alveolar (21%), and undifferentiated sarcoma/other (22%). A parameningeal primary tumor site was less common in this infant cohort (3%) than in all patients who were treated on IRS-IV (25%). The estimated 5-year failure-free survival and overall survival rates (95% confidence interval [CI]) were 57% (95% CI, 44%-67%) and 76% (95% CI, 65%-85%), respectively, for infants compared with 81% (95% CI, 79%-83%) and 87% (95% CI, 85%-89%), respectively, for children ages 1 to 9 years. Twenty-three of 32 infants with treatment failure had local recurrence/progression with distant failure (n = 3) or without distant failure (n = 20). The overall local failure rate was 30%. The median time to treatment failure was 13 months. The failure-free survival rate was worse for infants who had IRS Group III tumors and for those who received less than protocol-recommended radiation therapy.

Conclusions: Infants with RMS appeared to have worse outcomes than older patients, in part because of high rates of local failure. The authors concluded that concerns regarding morbidity in infants and reluctance to use aggressive local control measures may lead to higher rates of local failure.

Conflict of interest statement

Disclosures: None of the authors have financial relationships or interests to disclose

Copyright © 2011 American Cancer Society.

Figures

Figure 1

Age at diagnosis is prognostic of outcome in RMS. Infants have poorer FFS than older patients with RMS. (A) Estimated 5-year FFS (95% CI) by age group are 57% (44%,67%) for age

Figure 1

Age at diagnosis is prognostic of outcome in RMS. Infants have poorer FFS than older patients with RMS. (A) Estimated 5-year FFS (95% CI) by age group are 57% (44%,67%) for age

Figure 2

Failure-Free Survival by IRS Group. Estimated 5-year FFS (95% CI) by IRS Group are 89% (62%,97%) for Group I, 69% (37%, 87%) for Group II, and 39% (24%,53%) for Group III (p-value = 0.0022).

Figure 3

Outcome for infants Group III tumors was compared between those who received any RT and those who received no RT. (A) Estimated 5-year FFS are 47% (24%,67%) with RT and 32% (14%,51%) without (p-value = 0.17). (B) Estimated 5-year OS are 63% (37%,80%) with RT and 58% (35%,76%) without (p-value = 0.49).

Figure 3

Outcome for infants Group III tumors was compared between those who received any RT and those who received no RT. (A) Estimated 5-year FFS are 47% (24%,67%) with RT and 32% (14%,51%) without (p-value = 0.17). (B) Estimated 5-year OS are 63% (37%,80%) with RT and 58% (35%,76%) without (p-value = 0.49).