amplification predicts poor prognosis based on interphase fluorescence in situ hybridization analysis of bone marrow cells in bone marrow metastases of neuroblastoma.

Background: gene amplification is related to risk stratification. Therefore it is important to identify accurately the level of the gene as early as possible in neuroblastoma (NB); however, for patients with bone marrow (BM) metastasis who need chemotherapy before surgery, timely detection of the gene is not possible due to the unavailability of primary tumors.

Methods: gene status was evaluated in 81 BM metastases of NB by interphase fluorescence in situ hybridization (FISH) analysis of BM cells. The clinicobiological characteristics and prognostic impact of amplification in NB metastatic to BM were analyzed.

Results: amplification was found in 16% of patients with metastases, and the results were consistent with the primary tumors detected by pathological tissue FISH. amplification was associated with age, lactate dehydrogenase (LDH) levels and prognosis ( = 0.038,  < 0.001,  = 0.026). Clinical outcome was poorer in patients with amplification than in those without amplification (3-year EFS 28.8 ± 13.1 vs. 69.7 ± 5.7%,  = 0.005; 3-year OS 41.5 ± 14.7 vs. 76.7 ± 5.5%,  = 0.005).

Conclusions: amplification predicts a poor outcome in NB metastatic to BM, and interphase FISH of bone marrow cells provides a timely direct and valid method to evaluate the gene status.