Multimodality approach is essential
- Surgery
- Multiagent chemotherapy
- Radiotherapy
Multiagent chemotherapy is required for all stages and clinical groups.
Local therapy can be surgery alone, a combination of radiotherapy and surgery or radiotherapy alone.
Local control strategies vary based on primary tumor site, histology and the RISK GROUP.
SURGERY
PRIMARY TUMOR
- Complete surgical resection at the time of diagnosis is ideal if feasible to attain either clinical group I (complete resection) or II (microscopic residual disease) status. In embryonal histology stage 2 or 3 tumors this changes the risk group from intermediate to low risk.
- Operative management depends on location and extent of the tumor and complete resection is attempted if possible without injury to surrounding vital structures than may cause long term morbidity (eye, bladder, facial involving branches of the facial nerve, etc)
- If an embryonal rhabdomyosarcoma has been completely excised with negative histologic margins (Clinical Group I) then radiation therapy (RT) may be avoided altogether.
- If surgery results in only microscopic residual disease (Clinical Group 2) then a lower dose of RT may be used (versus the dose required for gross residual disease).
- Unfortunately the majority of patients (approximately 75%) will have macroscopic residual disease (clinical group III) due to inability to perform safe, complete surgical resection at the time of diagnosis.
- Biopsy alone is performed in cases where resection would lead to unacceptable morbidity due to injury or loss of vital structures.
REGIONAL LYMPH NODES
- Physical examination and imaging evaluations (CT or PET-CT) of lymph nodes should be done pre-operatively
- Regional nodes - should be biopsied for staging purposes in extremity and genitourinary sites.
- Cervical nodes should not be biopsied unless there is evidence of involvement based on clinical exam or imaging.
- Radical neck dissections are not necessary and not recommended.
CHEMOTHERAPY
- The Intergroup Rhabdomyosarcoma Study Group (IRSG) formed in 1972 to coordinate rhabdomyosarcoma research in North America
- Overall survival at 5 years has improved from approximately 25% in the early 1970s when combination chemotherapy was first introduced to over 70% in the most recent IRS protocols.
- Vincristine, actinomycin D and cyclosphosphamide (VAC) have formed the basis for all IRS protocols and remain the first-line as no other drug combination has been shown to show significant survival advantage.
RADIATION THERAPY
Discussed in detail in the outlines of treatment for each risk category.
