Prognosis and Prognostic Factors

In a 1999 study of 605 children, the prognosis was most favorable (5-year survival rates, 50%–70%) for children who initially presented with Stage 1 or Group I disease and embryonal/botryoid histology with small tumors and for those with local or regional nodal recurrence. Patients with Group I alveolar rhabdomyosarcoma or undifferentiated sarcoma had 5-year overall survival (OS) rates of 40% to 50%. This population of patients with improved outcomes encompasses only 20% of all patients with a relapse.[1][Level of evidence C1]

In a 2014 study of 24 children, 22 (82%) children with initially localized orbital sarcoma survived at least 5 years after relapse following re-treatment with curative intent.[4][Level of evidence C1]

A 2005 study of 125 patients with nonmetastatic rhabdomyosarcoma whose disease recurred after previous complete remission observed that favorable factors at initial diagnosis included: nonalveolar histology; primary site in the orbit, genitourinary/nonbladder-prostate, or head/neck nonparameningeal regions; tumor size of 5 cm or smaller; local relapse; relapse after 18 months from the primary diagnosis; and lack of initial radiation therapy (RT).[2]

A report of 337 patients with nonmetastatic rhabdomyosarcoma in 2008 observed that favorable factors at initial diagnosis were age 10 years or younger, embryonal histology, tumor size of 5 cm or smaller, favorable site, and lack of initial RT.[5]

In a 2009 study of 234 patients who had a relapse after achieving complete remission and completing primary treatment, the favorable prognostic factors for 3-year OS were reported. These factors were favorable primary site, local relapse, time to relapse of more than 12 months, tumor size of 5 cm or smaller, and no previous RT.[6][Level of evidence C1]

A 2011 study of 474 patients with nonmetastatic rhabdomyosarcoma who had complete local control at the primary site noted the unfavorable factors for survival 3 years after first relapse. These unfavorable factors included relapse with metastatic disease, previous (initial) RT, tumor size more than 5 cm, time to relapse of less than 18 months, regional lymph node involvement, alveolar histology, and unfavorable disease at primary diagnosis.[7]

In 2013, 90 patients with nonmetastatic alveolar rhabdomyosarcoma were re-treated with additional chemotherapy, with or without local re-excision of the primary site (if indicated) and with or without RT. The four most important factors for survival after relapse were no lymph node involvement, no metastases, adequate local therapy, and a second complete remission. The OS rate at 5 years was 21%.[8][Level of evidence C1]

A single-institution, retrospective review identified 23 patients with central nervous system (CNS) relapse after initial treatment for rhabdomyosarcoma.[9][Level of evidence C1] High-risk features at initial presentation included 16 alveolar patients, 13 Stage 4 patients, and 13 patients with primary tumor in parameningeal locations. All of the patients died. Twenty-one patients died of CNS disease, and two died of metastatic disease at other sites. Median survival post-CNS relapse was 5 months (range, 0.1–49 months).