Application of the Cox proportional hazard model revealed that T3-T4 classification of the tumour (HR, 6.36, p = 0.001) and de novo expression of NG2/CSPG4 mRNA (HR, 6.76, p = 0.017) were independent, robust prognostic factors for local tumour recurrence (Table 4; Figure 5). This evidence concerns the gene CSPG4 and neoplasm.