Local Control Management: Surgery
In recent years, the predominant site of treatment failure in patients with initially localized rhabdomyosarcoma has been local recurrence. Both surgery and radiation therapy are primarily measures taken to produce local control, but each has risks, as well as benefits. Surgical removal of the entire tumor should be considered initially, but only if major functional/cosmetic impairment will not result. With that proviso, complete resection of the primary tumor with a surrounding margin of normal tissue and sampling possibly involved lymph nodes in the draining nodal basin is recommended. Important exceptions to the rule of normal margins exist (e.g., tumors of the orbit and of the genitourinary region).[2,3] The principle of wide and complete resection of the primary tumor is less applicable to patients known to have metastatic disease at the initial operation, but it is a reasonable concept if easily accomplished.
Patients with microscopic residual tumor following their initial excisional procedure appear to have improved prognoses if a second operative procedure (primary re-excision) to resect the primary tumor bed before beginning chemotherapy can achieve complete removal of the tumor.
Clinical and/or imaging evaluation of regional lymph nodes is an important part of pretreatment staging. Pathologic evaluation of regional nodes is currently required for all patients with extremity primary rhabdomyosarcoma and boys aged 10 years and older with paratesticular rhabdomyosarcoma, because microscopic tumor is often documented even when the nodes are not enlarged. (Refer to the Regional and in-transit lymph nodes section of this summary for more information.)
There is little evidence that debulking surgery (i.e., expected to leave macroscopic residual tumor) improves outcome, compared with biopsy alone.[Level of evidence: 2A] Second-look procedures (also known as delayed primary excision) can identify viable tumor that remains after initial chemotherapy; patients with viable tumor had shorter event-free survival (EFS) rates than did those without viable tumor, but there was no effect on overall survival (OS). Thus, the exact role of delayed primary excision remains undefined in rhabdomyosarcoma and is most appropriate if it is anticipated that a complete resection is possible and that the modest reduction in radiation dose will substantially decrease the risk for late effects.
Because rhabdomyosarcoma can arise from multiple sites, surgical care decisions and radiotherapeutic options must be tailored to the specific aspects of each site, and should be discussed with a multidisciplinary team including representatives of those specialties, as well as pediatric oncologists. Surgical management of the more common primary sites is provided in the Local Control Management with Surgery and RT by Primary Sites of Disease section of this summary.
Local Control Management: Radiation Therapy (RT)
Only 15% of patients present with Group I, completely resected disease, so RT is used in the majority of cases.