Based on Stage, Clinical Group and histology patients are now placed in different risk categories.
LOW RISK
- Embryonal pathology in favourable sites, as long as no distant metastatic disease (Clinical Groups I, II and III).
- Embryonal pathology at unfavourable sites if either completely resected disease or microscopic residual disease (Clinical Groups I and II).
These patients have a 5-year failure-free survival (FFS) of 85% on Intergroup Rhabdomyosarcoma Studies (IRS)-III (1984 – 1991)1 or IV (1991 – 1997).
Results of IRS-III and IRS-IV showed that non-metastatic tumors of embryonal histology arising in favorable sites (Stage 1) and also those with tumors in unfavorable sites (Stages 2 and 3) that are grossly resected (Clinical Groups I and II) have good 5-year FFS (~83%) and overall survival (OS) (~95%).
Subset A
Patients with embryonal RMS with
- Stage 1 (favorable site), Clinical Group I (completely resected) tumors
- Stage 1, Clinical Group IIA (microscopic residual disease, no regional node involvement) tumors
- Stage 1, Clinical Group III (gross residual disease) orbital primary tumors
- Stage 2 (unfavorable site, size < 5 cm, no regional node involvement), Clinical Group tumors
Patients in subset A have a five year failure free survival of just over 80% and a five year overall survival of over 90% with two-drug chemotherapy (Vincristine (V) and Dactinomycin (A) (VA) for 32 -54 weeks.
Subset B
Patients with embryonal RMS with
- Stage 1, Clinical Group IIB or C (regional node involvement without [B] or with [C]microscopic residual disease) tumors
- Stage 1, Clinical Group III non-orbital primary tumors
- Stage 2, Clinical Group II tumors
- Stage 3 (unfavorable site, size > 5 cm and/or regional node involvement), Clinical Group I or II tumors
Patients in Subset B achieved similar outcome
INTERMEDIATE RISK
Embryonal rhabdomyosarcoma with gross residual disease (Clinical Group III) occurring at unfavourable sites (stage 2 & 3).
Non-metastatic alveolar rhabdomyosarcoma at any site.
Metastatic embryonal rhabdomyosarcoma less than 10 years old has been considered in this risk group previously, but is currently included in the open high risk COG protocol (ARST 0431).
HIGH RISK
Metastatic rhabdomyosarcoma at presentation.
