[Value of prognostic factors in the Austrian A-NB87 Neuroblastoma Study].

AIMS

A multivariate analysis was performed to evaluate the impact of various prospectively evaluated risk factors.

PATIENTS AND METHODS

From January 1987 to December 1993, 120 patients were registered in the study. 108/120 patients were eligible. There were 49 girls and 59 boys with a median age at diagnosis of 14 months (range, 0 to 224 months). Patients were classified according to the Evans classification system. LDH, NSE, Ferritin, N-myc amplification, 1p-deletion and ploidy were evaluated at diagnosis. Treatment intensity was based on the results of primary surgery: surgery only for 22 (20%) stage I and IIA patients (macroscopic residue without lymph node involvement), the 9 IIB patients (8,5%) (macroscopic residue with lymph node involvement) had mild chemotherapy in addition (6 x VCR/CYC) and elective radiation (Rx). Stage III patients were divided into 2 groups: IIIA patients (n = 17/16%) had to have ferritin levels under 300 micrograms/ml, NSE lower than 100 ng/ml and age below 2 years at diagnosis and received 6 alternating cycles of DAMO/ MVDOC. If one of these three criteria was not fulfilled, patients were assigned to the more intensive treatment arm stage IIIB (n = 12/11%), i.e. 9 alternating cycles of DAMO/MVDOC/IPE. Stage IV pts (n = 35/32.5%) received 8 MVDOC/IPE cycles and 20 patients received megatherapy followed by stem cell reinfusion in addition. 13 stage IVs patients (12%) were registered and had elective VCR/CYC and/or liver radiation in case of poor clinical condition. The median observation time is 4.2 years (range, 1 to 7.5).

RESULTS

The survival rate at 3 years was excellent for localized disease and stage IVs with survival rates of 100% for stage I/IIA and 92% for stage IVs. Stage IIIA patients had an EFS rate of 81% whereas stage IIB patients achieved only 69%. Stage IV patients reached 51%, however outcome was especially poor for stage IIIB patients (20%) due to treatment related toxicities. The toxic death rate in the study was 13% (2 surgical deaths, 8 infections, 4 multiple organ failures). Univariate analysis demonstrated the following significant unfavorable risk factors: age over 1 year at diagnosis (58/108 pts, p = 0.006), NSE > 100 ng/ml (26/95 pts, p < 0.0001), Ferritin > 300 ng/ml (19/98 pts, p = 0.007), LDH > 300 (400) U/L, 51/87 pts, p = 0.004), presence of N-myc amplification (17/59 pts, p = 0.001), deletion of the short arm of chromosome 1 (19/74 pts, p < 0.0001) and di/tetraploidy (32/72 pts, p = 0.008). The power of these factors was even stronger in patients with localized disease whereas no significant prediction was observed for stage IV patients. Furthermore a significant correlation of the serological (NSE, ferritin, LDH) and biological factors (N-myc, deletion 1p, di/tetraploidy) was detected in this study. Only NSE was identified as an independent prognostic factor (p = 0.018) whereas no independent factor could be identified within the 3 biological parameters due to their high correlations (Kendall's tau for N-myc and deletion 1p:0.7). However, N-myc (p = 0.005) as well as deletion 1p (p = 0.01) were found significantly more important than di/tetraploidy.

CONCLUSIONS

Biological classification of neuroblastomas should be mandatory and be the prerequisite for any risk adapted treatment. One serological and 2 biological factors could be a good standard evaluation to identify neuroblastoma patients at risk.