BACKGROUND: Rhabdomyosarcoma (RMS) is the most common
soft tissue sarcoma in
children . Alveolar RMS (
ARMS ) is characterized by FOXO1-related
chromosomal translocations that result in a poorer clinical outcome compared with embryonal RMS (ERMS). Because the chromosomal features of RMS have not been comprehensively defined, we analyzed the clinical and
laboratory data of childhood RMS
patients and determined the
clinical significance of
chromosomal abnormalities in the
bone marrow .
METHODS: Fifty-one Korean
patients with RMS < 18 years of age treated between 2001 and 2015 were enrolled in this study. Clinical factors,
bone marrow and
cytogenetic results, and overall
survival (OS) were analyzed.
RESULTS: In total, 36
patients (70.6%) had ERMS and 15 (29.4%) had
ARMS ; 80% of the
ARMS patients had stage IV
disease . The
incidences of
bone and bone marrow metastases were 21.6% and 19.6%, respectively, and these results were higher than previously reported results. Of the 40
patients who underwent
bone marrow cytogenetic investigation, five
patients had
chromosomal abnormalities associated with the 13q14 rearrangement.
Patients with a
chromosomal abnormality (15 vs 61 months, P=0.037) and
bone marrow involvement (17 vs 61 months, P=0.033) had a significantly shorter median OS than those without such characteristics. Two novel rearrangements associated with the 13q14 locus were detected. One
patient with concomitant MYCN amplification and PAX3/FOXO1 fusion showed an aggressive
clinical course .
CONCLUSIONS: A comprehensive approach involving conventional
cytogenetics and FOXO1 FISH of the
bone marrow is needed to assess high-
risk ARMS patients and identify novel
cytogenetic findings.